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2010-03-26
The time-lag argument for the representational theory of perception
Hello

I would be very grateful for people's thoughts on the following particular form of the time-lag argument for the representational theory of perception:

1) One's vision is dependent on visual information travelling from one's eyes to the visual areas of one's brain, and then being processed, all of which does not happen instantaneously, but takes a finite amount of time, however small.

2) Therefore, the content of one's vision in the present is always the world of the past, however recent.

3) The past, however recent, cannot itself exist in the present, by definition, although a representation of it can.

4) Therefore, what one directly experiences, visually, when one looks at the world cannot be the world itself, and must instead be merely a mental simulation of it, generated by one's brain from the information that it receives from one's eyes.

A common objection to the time-lag argument is that what follows from the perceptual lag is not that we do not experience the world directly, but 'merely' that we cannot directly experience the world without a delay. However, I think that the above form of the argument anticipates this objection - that is, if we experience the world with a delay, then what we directly experience must be the world of the past, and yet the world of the past cannot exist in the present, although a representation of it can.

For example, the visual lag is about 100ms, or 0.1s. Given that lag, someone walking in front of you at a relatively slow pace of 1 metre per second will have actually travelled about a further tenth of a metre from where you perceive them to be at any moment. Likewise, a car travelling at 10 metres per second - about 22 miles per hour - will have travelled about a further metre from where you perceive it to be at any moment. In both of these cases the content of your vision in the present is clearly not the world of the present, but of the past. And as the argument points-out, the past cannot itself exist in the present, by definition, although a representation of it can.

With respect to step 4, I of course appreciate that there are plenty of counterarguments against this statement, but I'm really just interested here in people's thoughts on the above argument.

I've posted the first draft of a 'popular philosophy' article (1,155 words) on the above form of the time-lag argument on my website:

http://www.chainsofreason.org/this-is-a-simulation-1

With best wishes

Derrick

2010-03-29
The time-lag argument for the representational theory of perception
Very interesting. Haven't read the other comments yet, but is this supposed to be an argument against naive realism?

I like where you are going, but it would help me if you could explain how step 3 follows from step 2.  Suppose the content of my visual state is an event that took place a little while ago.  Why does this imply that my visual state represents, rather than contains, that event?  I am not sure what it means to say that the past can't exist in the present, or why this is relevant.  Why couldn't I say that my visual state contains, rather than represents, an event that doesn't exist in the present (whatever that means)? Or why can't I say that it contains the present fact designated by "A little while ago, this"?

All of this is very interesting to me because I am currently thinking about the explanatory power of naive realism.  It would help me if you were more explicit.

best,

Mohan

2010-03-31
The time-lag argument for the representational theory of perception
Reply to Mohan Matthen
'if we experience the world with a delay, then what we directly experience must be the world of the past, and yet the world of the past cannot exist in the present, although a representation of it can'.

This argument contains a suppressed premiss, namely, that we can only directly experience what exists in the present. (If I directly experience something, it exists simultaneously with my
experience of it.)
That needs defending, in fact.

Suppose the past is real, past events exist but they are before the time at which I write these words. So these past events, though they do not exist now,
exist, just as Mt. Everest, though it does not exist here (where I am), exists. This is called Eternalism. Time is like space, and past moments are as real as present ones,
just not present (just as other places are real as this place, only not here.) Well then, as these events are real and cause my present perceptual experience,
why can't I experience them directly even though what I experience doesn't exist in the present?

On the other hand if one might agree with Augustine that the past is no more, it's vanished like the snow, only the present moment is real, There is only one moment of time.
This is called Presentism. The Present moment alone is real.
Then there is a problem, for how can I directly experience what doesn't exist?

Thanks for the interesting argument.

2010-04-02
The time-lag argument for the representational theory of perception
Dear Derrick,
To a first approximation your assessment of the time lag argument must be right. There are dozens of ways of arguing this. In fact if a student of perception puts themself in the position of testing their hypothesis in any practical way whatever they will find themselves compelled to conclude that what we experience is something constructed in the brain from sensory inputs both recent and past. The nature of the construct is always as much dependent on the nature of the sense organs as on the physical influences from outside. 'Directly experiencing the world' turns out to be a pseudodynamic folk concept that cannot be explicated without self-contradiction. 

However, the reason why there may still be debate amongst philosophers about what is done and dusted fact in physiology labs is that the alternative to direct perception that you give in (4)  is also inconsistent with science. What we experience is not a mental simulation of the world. It is an experience determined by physical laws operating both outside and inside the brain. The operation of these laws does not in itself have any appearance (because appearance is always appearance to something). There is no 'stuff' out there that our experience 'simulates'. Such an idea is as self contradictory as the direct perception one and modern physics shows empirically that it is invalid. All we can say is that the world consists of 'what is really going on' and that this is the operation of instances of dynamic physical laws. There is no such thing as a 'veridical' experience, in the sense of being 'truly like the world', simply one that depends on the dynamics of our current environment in a way that we can readily dissociate from influences from e.g. the dynamics of some past event that flavours our interpretation of the present or some inconsistency in the dynamics of our sensory organs. 

Another way of putting it is that the concept of 'representation' is too imbued with intuitive category mistakes that it is best jettisoned. Our experience is not a re-presentation of a world (that has previously been 'presented'). It is not even a presentation, I suspect. It is an actuality determined by the operation of instances of dynamic laws that are real and concrete but unenvisageable as 'stuff in a space'.

Jo E

2010-04-02
The time-lag argument for the representational theory of perception
Hi,

I don't know whether this of any help, but I would have thought a possible weak point of the argument is premise 3. This premise sounds (because of the word "definition") like an analytic proposition and could perhaps be challenged as such eg "maybe the past can exist in the present" (though I'm not sure how!). Also, if one has ordinary language philosophy sympathies, one might say, in relation to 4, what we mean by "direct experience" is just what we see, whether it was 4 seconds ago or not. I suppose, like most philosophical problems, it depends on ones philosophical stance (ie one's metaphilosophy).

Best Wishes

Garry 

2010-04-02
The time-lag argument for the representational theory of perception
I think there is something wrong with premise three. The premise contains the assumption that only the present exists. If the past does not exist in the present, then it is not true that the past exist in the present. Since it is now the present, then it is not true that the past exists. This might be a defensible position, but it is not very attractive. The view would entail denying the existence of the holocaust for example. It is widely accepted that the Nazi Holocaust is in the past. But if the past does not exist, it means that the holocaust does not exist. So as well as being metaphysically unattractive, such a view is actually illegal in some countries.
If this feels like word play and some kind of logical fun and games, then consider more deeply. How short is the present? How is the present located? A way to answer the first question would be to list journal articles that you consider to be contemporary. What is the most recent philosophy paper that you consider to be in the past? What are you doing now? The problem here is that there does not seem to be a minimum unit that is non arbitrary, and if you just take a one dimensional point on a time line, then premise three means that nothing with any duration exists at all.
When talking about cosmology some people like to say in a tone of wonder that when we look at the stars, we are looking at events that took place thousands of years ago. According to premise three, this means that we are looking at events that do not exist. People will also say in this context, that this star that we see here may no longer exist, since it may have collapsed in the time it took the light to travel to earth. We would then get something like this pair of claims:
1. This star we now perceive used to exist
2. This star does not now exist.
The conclusion is
3. What we now perceive does not now exist.

This seems fine, but it does not seem to follow that the object that we are picking out by ostensive definition "That star (pointing at the star)" does not exist"; this cannot follow because we are picking out the thing by ostension. And we are not pointing into our visual cortex but out at the night sky in the direction of the star.


2010-04-02
The time-lag argument for the representational theory of perception
Hi Derrick,

I have some comments and criticisms of your argument.  I also have a suggestion for an alternative way of approaching the issue.

I think you are making a common error by regarding experience as the result of neurological functioning, and not as some aspect (or aspects) that very functioning itself.  For, if we suppose that visual experience is the way that the eyes and brain respond to visual stimulation, then experience begins the moment light interacts with the eyes.  We should therefore reject your first premise. Information our eyes receive from light may directly contribute to our visual experiences, and partially (if not wholly) constitute some level of experience.

Your second point is worded strangely.  You say, "the content of one's vision in the present is always the world of the past."  I could see you wanting to claim that visual content is always a representation of the world of the past (though, again, I do not think you have made a case for this claim).  However, I see no motivation for the claim that the content of visual perception is the actual world of the past. 

Also, I can think of two reasons to reject your third point.  First, what if we take the notion of a block universe seriously?  If time is something like another spatial dimension, as physicists are known to suggest, then the past, present, and future might exist simultaneously.  Second, the objects we perceive persist over time.  The tree I see still exists, even though it takes me some time to form a representation of it.  Of course, it may have changed slightly during that time; but my representation need not be a perfect copy for it to be a useful representation of the present world, and not merely an outdated representation of time past.  Whatever lag might exist must be small enough to allow for the sorts of activities which our genes (if not our dreams) require.

As for your fourth point, there is a difference between a representation and a simulation.  Even if we were compelled to accept your first three points, it would not follow that we experience simulations, as opposed to representations.

Finally, here is an alternative way of observing the indirect relationship between objects and experience.  I will focus on vision, though I think similar arguments can be made for other sense modalities.  In the case of vision, all we directly perceive with our eyes is light.  Our eyes respond to light, which itself is responding to other objects, and we construct images of those objects.  Perhaps we have some innate templates, so that we do not have to construct the first objects we see from scratch.  But, as we construct objects, we learn how to see differently.  Our new visual experiences are shaped by the ways we have constructed the contents of past visual experience.  So, on the one hand, we do create visual contents, and they can represent the world. On the other hand, we must use information from the world to create the contents of visual experience.  It cannot all come from us, or there would be no feedback, no development, no interaction.  So the fact that we are constructing representations does not mean our experience is only of those representations.  We do experience the representations, of course--but that is a different sort of experience, an experience of reasoning, reflection, and so on.  In sum, there is a way of experiencing which is not an experience of a representation, but which is a process of forming a representation.  When we experience representations, we experience the world indirectly.  But when we create representations, we are experiencing the world directly.

Regards,
Jason
March 29, 2010

2010-04-02
The time-lag argument for the representational theory of perception
The greatest hockey player Wayne Gretzky's quote; "I skate to where the puck is going to be, not where it has been."

The fact that we have time lags in our perception and motor skills; or this is how and why we develop skills and thought.  We can say that time is "figured in" to all of the networks and formulas which is skill memory.

2010-04-02
The time-lag argument for the representational theory of perception
Hi Derrick,

I wonder what becomes of "the present" if this argument is true. Presumably "the present" is when light - which is reflected off objects - hits the retina, and it is only after the time it takes the brain to process this (0.1 seconds, you say) that we "perceive" these objects as being present (for us). I don't disagree with this, but then, it seems a necessary procedure in order for any perception - or the subjective acknowledgment of those objects from which light has been reflected - to occur. That is, I side with the objection, which you note, "that we cannot directly experience the world without a delay". This is just a repeat of your first statement.

On your last statement, I'm unsure why "what one directly experiences, visually, when one looks at the world cannot be the world itself". What would it be a visual experience or representation of, if not the "world itself"? When you go on to say "and must instead be merely a mental simulation of it, generated by one's brain from the information that it receives from one's eyes," I wonder what you mean by "simulation". Do you allow for the processing of visual information - that you speak about in your first statement - to normally provide us with reliable information about the world (from which the light hits our retinas)? Or, is it just a "simulation"? Or, do you consider there to be little difference between a "simulation" and "processed visual information"?

I don't disagree that there is a time lag, but I see it as a time lag which is necessary in order for us to have "direct experiences". We might consider an ideal situation in which the processing of visual information - from light hitting the retina to "object acknowledgment" - is instantaneous and without delay, but I assume that the processing of information (or work, generally) always requires some time. It is this instantaneous, lag-less "objective present" which you appear to refer to as "the world itself", of which we can only ever have a representation or simulation, but isn't the "object acknowledgment", which follows the processing of visual information, just what we mean by a direct (visual) experience?

I think part of the problem here may be your assumption that a "direct experience" must occur in the "objective present" (when light hits the retina). That is, it could be that what we usually mean by "the present" is not the "objective present". I have merely presumed here, following you, that the "objective present" is when light strikes the retina. However, I take it as generally accepted that the present moment is indexical, and is therefore defined by the time at which we are conscious, even if our consciousness is of events which occurred 0.1 seconds in the past of some "objective present".

Luke.

2010-04-02
The time-lag argument for the representational theory of perception
Reply to Mohan Matthen
Hello Mohan

Thanks very much for your reply.
... is this supposed to be an argument against naive realism?
I would say that the argument is more specifically against direct perception, rather than direct (or naive) realism, although the conclusion can of course be used as the main premise of a very simple argument against direct realism.
... it would help me if you could explain how step 3 follows from step 2.
Step 3 is actually just a premise, like step 1.
Suppose the content of my visual state is an event that took place a little while ago.  Why does this imply that my visual state represents, rather than contains, that event? I am not sure what it means to say that the past can't exist in the present, or why this is relevant. Why couldn't I say that my visual state contains, rather than represents, an event that doesn't exist in the present (whatever that means)?
... (expand) Isn't it true by definition that the past and present exist at different moments at time, and so the past cannot exist in the present? And if so, then if what you are directly experiencing, visually, in the present is the world of the past, then what you are directly experiencing must actually be merely a representation of the past, not the past itself.
 Or why can't I say that it contains the present fact designated by "A little while ago, this"?
Sorry, I'm not sure what you mean here.

Derrick

2010-04-02
The time-lag argument for the representational theory of perception
Reply to Jim Stone
Hi Jim

Thanks very much for your reply.

You say:
... as these events are real and cause my present perceptual experience, why can't I experience them directly even though what I experience doesn't exist in the present?
But as we are experiencing something - a perception, a thought, an emotion, a memory, etc. - whatever it is that we are directly experiencing in the present must, by definition, exist in the present as it is being experienced. And if, as you agree above, what we experience, perceptually, in the present is the past, but the past itself doesn't actually exist in the present, then it must be merely a representation of the past that exists in the present.

With best wishes

Derrick

2010-04-02
The time-lag argument for the representational theory of perception
Hi Derrick,

Thanks.  Now, I can better see where you are going with this.

Gareth Evans proposed that when you see something happening, you see it as happening now.  You would like to amend this -- actually you see it as happening a few milliseconds ago. And you think that if this is true, then since what happened in the past does not now exist, you must be representing what happened.

Though I am a proponent of representationalism, I don't think that your conclusion is compelled without further metaphysical premises.  It is possible to hold that there are eternally existing facts.  For example, you could hold that the event of Caesar crossing the Rubicon in 49 BC (or 2149 years ago) is an eternally existing event.  On this view, when you see a blue ball bouncing, you are in contact with the event of the blue ball bouncing a little while ago.

As Jim Stone said earlier in the thread, perhaps you are assuming presentism -- the view that past entities no longer exist in any sense at all.  But that's a pretty radical view with many counter-intuitive consequences.  For example, it has the consequence, barring desperate remedies, that it is not now true that Caesar once crossed the Rubicon. 

Do you want your theory of perception to rest on a metaphysical thesis of this sort?  I would much rather argue for representationalism on cognitive-science grounds, in the manner of Jonathan Edwards earlier in the thread (though he finds reasons to be dubious of that direction as well). 

best,

Mohan


2010-04-02
The time-lag argument for the representational theory of perception

‘But as we are experiencing something - a perception, a thought, an emotion, a memory, etc. - whatever it is that we are directly experiencing in the present must, by definition, exist in the present as it is being experienced.’

This is a fallacy of equivocation.

‘Whatever it is that we are directly experiencing in the present’ might mean

(1) Whatever it is we have a present experience of

or

(2) Whatever it is in the present that we are experiencing.

Your assertion is true for (2) but it simply doesn’t follow that it is true for (1),
which is what your argument needs. Indeed, put in (1) and your assertion is false,
for it isn’t true BY DEFINITION that whatever it is that we have a present experience of must exist in the present. 

2010-04-03
The time-lag argument for the representational theory of perception
I have to admit to being somewhat dismayed by the usage of words in this debate. I understand philosophy to be about taking maximum care over the premisses introduced into argument. That starts with making sure that words are unambiguous. Within science there is a tacit acceptance that words often have several meanings relating to completely different ontological categories and although this is sloppy and potentially hazardous it is usually resolved by being clear about context. Thus time and space relate to at least three quite different sorts of concept, dynamic, historic and experiential. Only certain meanings of time have a present (and even these are not necessarily commensurable). If you try talking of a present using time in another sense you get into this sort of mess. 'Exists' has several different meanings. 

It worry that philosophers, rather than being picky about what words mean, often find it hard to accept that almost all the important words in metaphysics have this sort of ontologically diverse polysemy. This is all the more odd since a ten year old child can see that 'the event of Caesar crossing the Rubicon exists' tells us more about the muddled structure of our language than about the nature of the world. They would be puzzled because it uses words in a context that we learn to avoid because it tends to force us to conflate meanings. Peirce, Russell, Frege, Carnap, Sellars and others had things to say about this but I am unclear that any of them fully understood the complexity of metaphysical, rather than just operational, dichotomies underlying our words.


I could expand, but maybe I should just give a pointer to the principles (http://appearancesandrealities.blogspot.com) that seem to me to underly the current question.


2010-04-03
The time-lag argument for the representational theory of perception
Adams, “Time and Thisness;” Bourne, A Future for Presentism; Bigelow, “Presentism and Properties;” Hinchliff, “The Puzzle of Change;” Keller and Nelson, “Presentists Should Believe in Time-Travel;” Markosian, “A Defense of Presentism;” McCall, A Model of the Universe; Sider, Four-Dimensionalism; Sider, “Presentism and Ontological Commitment;” Tooley, Time, Tense, and Causation; Zimmerman, “Persistence and Presentism;” Zimmerman, “Temporary Intrinsics and Presentism.”

If you haven't done them already, I think these readings are helpful on your concerns about our talk about time. Also the recent literature on three- and four- dimensionalism.
Thanks for the reference to your blog, which I've looked at and will return to.

All the best, Jim

2010-04-03
The time-lag argument for the representational theory of perception
Now, now, Jonathan, please stay calm. 

It is fairly standard (though not absolutely de rigeur) to hold that 'exists' has the same meaning even when applied to different kinds of things, e.g.:

The number seven exists

and

The event of Caesar crossing the Rubicon exists.

Of course, what it is for an abstract object to exist is different from what it is for an event to exist -- but it does not follow that the meaning of 'exists' is different in these cases.  (Compare: what it is to win in chess is different from what it is to win in rugby, but the same sense of 'win' applies to both.)  My sense of 'exists' is that given by Quine: to exist is to be the value of a bound variable.

Again, it is absolutely de rigeur to hold that tense modifies 'exists' but that 'exists' has the same sense in 'exists in the past' (or 'existed') and 'exists in the present' (or 'existed').  (Compare: 'cross' has the same sense in 'crossed', 'is now crossing' and 'will cross'.)

In any case, my point had nothing to do with meanings of 'exists' and could have been made without using the world.  The point is that Caesar crossing the Rubicon now is a different (putative) event from Caesar having crossed the Rubicon in 49 BC. 

I know that event-talk is difficult for non-philosophers to digest, and the statement I just made would be controversial even within philosophy, for reasons not unrelated to the worries you raise, Jonathan.  But the time-lag argument has to take a position on the above, and I was suggesting that maybe that was a can of worms that Derrick did not want to open.

2010-04-04
The time-lag argument for the representational theory of perception
Hi Jo

Thanks very much for your reply.

You say that you agree that what we directly experience, perceptually, is not the world itself, but that you don't believe that it is a representation/simulation of the world. However, if the content of our perceptions is an experience of the world, but not a direct experience of the world, then doesn't that lead inevitably to the conclusion that what we directly experience, perceptually, is a representation of the world?

You write:
Such an idea is as self contradictory as the direct perception one and modern physics shows empirically that it is invalid.
I don't see how modern physics shows that the conclusion is invalid. Indeed, we know for certain that we do experience mental representations of the world, in the form of memories.

With best wishes

Derrick

2010-04-04
The time-lag argument for the representational theory of perception
Reply to Garry Todd
Hi Gary

Thanks very much for your response.

Step 3 is certainly open to challenge, it's just that I can't myself see how one could do so successfully.

Re step 4, I actually would myself say that what we directly experience, visually, is just what we see - but if what we see in the present is the world of the past, which can't itself exist in the present, then what we directly experience, visually, must be merely a representation of it.

With best wishes

Derrick

2010-04-04
The time-lag argument for the representational theory of perception
Jonathan,

I appreciate your concerns but we shall not forget that words convey a thought or an idea. Let us assume that words mean what they generally mean to a layman and then understand and resolve the issue.

The crux of the issue is the confusion about an event happening and its perception by us. These are two unrelated phenomena in the sense that occurrence of an event has nothing to do with its perception (an event may occur without the presence of any observer unless we believe in Jordan's suggestion that observer creates the observed) and perception of an event, at least as per the Einstein's school (QM suggests that observer affects what is being observed), does not and cannot affect that which has happened.

In the normal sense of the words, past remains past and does not merge with the present but TOR allows the possibility that past, present, and future can merge at a single point.

However, as far as I can see it, the problem being discussed arises out of the confusion discussed above and not because of any scientific or philosophical analysis and as such, needs to be resolved more through the common sense rather than scientific or philosophical analysis.

Steps 1 to 4 are not related to each other and it is wrongly presumed that they 2 must naturally follow from 1 or 3 must be a consequence of 2.......




2010-04-05
The time-lag argument for the representational theory of perception
Reply to Jonny Blamey
Hi Jonny

Thanks very much for your response.

You write:
The premise [step 3] contains the assumption that only the present exists.
However, the premise is not saying that only the present exists, but that, by definition, only the present exists in the present. In the case of your example of the Nazi Holocaust, the premise doesn't exclude the possibility that this event occurred in the past - it merely excludes the possibility that this past event, which ended decades ago, can be said to be occurring in the present.
How short is the present?
I would say that the present is the instant in time separating the past and the future.
... if you just take a one dimensional point on a time line, then premise three means that nothing with any duration exists at all.
I don't see why one would derive that from step 3 if one defines the present as an instant in time.
When talking about cosmology some people like to say in a tone of wonder that when we look at the stars, we are looking at events that took place thousands of years ago. According to premise three, this means that we are looking at events that do not exist.
In this context, step 3 leads to the conclusion that we are looking at events that do not exist in present.

Re our vision of a dead star, you say that something must exist because we are pointing to it, but an hallucinator can point to an hallucinated object when asked to, even though no such object exists. In the case of the dead star, different people will all point in the same direction because they are all receiving the same visual information about the direction that the star was in when it originally emitted the light that is being received.

With best wishes

Derrick

2010-04-05
The time-lag argument for the representational theory of perception
Hi Jason

Thank you very much for your response.

You write:
if we suppose that visual experience is the way that the eyes and brain respond to visual stimulation, then experience begins the moment light interacts with the eyes.  We should therefore reject your first premise. Information our eyes receive from light may directly contribute to our visual experiences, and partially (if not wholly) constitute some level of experience.
But, as the first step states, our vision is the output of the visual process - we can't see until every step in the visual process has been completed. Therefore, our visual experience doesn't begin with light striking our eyes, which is merely the input to the visual process. I don't see how, as you suggest, the light striking our eyes could, in itself, contribute to our visual experience, before the information has reached the brain and been processed.
Your second point is worded strangely.  You say, "the content of one's vision in the present is always the world of the past."  I could see you wanting to claim that visual content is always a representation of the world of the past (though, again, I do not think you have made a case for this claim).  However, I see no motivation for the claim that the content of visual perception is the actual world of the past.
I believe that the use of the words 'content of' means that step 2 isn't stating either way whether what we directly experience, visually, is the world or a representation of it. For example, someone could say that the content of a photograph is the world of the past, and one wouldn't think that they were suggesting that the photograph contained the actual world of the past.
Also, I can think of two reasons to reject your third point.  First, what if we take the notion of a block universe seriously?  If time is something like another spatial dimension, as physicists are known to suggest, then the past, present, and future might exist simultaneously.
According to my understanding of this theory, I don't think that it states that the past, present and future exists simultaneously. I think that it states that, contrary to 'common sense', the past and future exists just as much as the present does. But I think that it still holds that the past exists in the past, and the future exists in the future.
Second, the objects we perceive persist over time.  The tree I see still exists, even though it takes me some time to form a representation of it.  Of course, it may have changed slightly during that time; but my representation need not be a perfect copy for it to be a useful representation of the present world, and not merely an outdated representation of time past.  Whatever lag might exist must be small enough to allow for the sorts of activities which our genes (if not our dreams) require.
But a representation of the past existing in the present isn't the same as the past itself existing in the present. Step 3 doesn't claim that the representation of the past isn't useful, but simply that it is indeed a representation of the past that exists in the present, not the past itself.
As for your fourth point, there is a difference between a representation and a simulation.  Even if we were compelled to accept your first three points, it would not follow that we experience simulations, as opposed to representations.
But if what we directly experience, visually, is a mental representation of the world, then I don't see why it cannot be said that that mental representation is a simulation of the world, given that it isn't that world itself. A simulation is simply as an imitation of something, and such a mental representation would indeed be an imitation of the world.

Re your last paragraph, I'm afraid I couldn't follow your argument. I don't understand why the creation of mental representations constitutes experiencing the world directly just because the information being processed is derived from the world.

With best wishes

Derrick

2010-04-05
The time-lag argument for the representational theory of perception
FEELINGS FOLLOW THEIR CAUSES

(1) A robot interacts with objects in the world via sensorimotor interactions (I/O).

(2) None of its inputs are simultaneous with its outputs, because the I/O is in real-time, serial and causal.

(3) Some I/O lags will be longer than others.

(4) A sentient robot like us also feels something during its sensorimotor interactions.

(5) In particular, when it is having an optical interaction with a chair, it feels like it's seeing a chair.

(6) The feeling, though hard to localize precisely in time, occurs in real time, and, though impossible to explain causally, is no doubt also part of the I/O causal sequence in real time.

(7) Hence feeling, too, like all output, is not simultaneous with the input that causes it, even when it feels like it.

(8) The only mystery in this is how and why the robot feels at all, not whether or why there is a lag.

(9) Perception is not "direct"; it merely feels direct -- but that's apparently good enough for government work.

(10) Don't ask whether we perceive objects (simultaneously) or their "representations" (after a delay). 

(11) Ask why and how our sensorimotor functions are felt at all. 

(12) That is the explanatory gap (q.v.) 

Stevan Harnad



2010-04-05
The time-lag argument for the representational theory of perception
Sound is produced at place A and it perceived at place B after t seconds.

Does it mean sound exists at place B?

No, it simply means that information has traveled to place B and has taken t seconds to do so and has manifested itself to a medium capable of manifesting that information.

Generation of sound and its manifestation are two different phenomena. We can manifest sound only in a specific range and if we cannot manifest sound of a specific frequency because of our natural observational limitations then it does not mean sound was not generated.

In your question, each step is independent of other steps.



2010-04-05
The time-lag argument for the representational theory of perception
Please, can you give me a link so I can explore to what you say here? I love it :) Thanks!

2010-04-05
The time-lag argument for the representational theory of perception

Hello, Jonathan and your repliers, it seems to me that there is an equivocation on "present" in this matter. The verb to present is to introduce someone or something, but the noun "the present" contrasts with past and future. What we get in sense perception, even with the time lag, is presented not represented, since to represent is to present again,and one cannot re-present what has never been presented. (One might simulate it.) he old notion of a species present did allow the recent past to be present, so the information we get in sense perception would then count as present, as well as presented. Its as direct as we get, what Hume called an impression, not an idea, which is always a representation, unless one thinks there are innate ideas. Its true that we may experience our current emotions without the small time lag there is in sense perception, so they may be more direct, and Hume's term "reflective impression" for them might have been better applied to sense perception, since not only is there the time lag, there is the influence of old information in how we interpret what we sense. Sorry if this seems pickily linguistic, and overly respectful to Hume, but I do think he avoids the sort of mess you are getting into. However, some, like Donald Ainslie, think there is what he calls "image-content" in a Humean sense impression, so they do then become simulaters, if not strictly re-presentations. I suggest you check whether you can insert that hyphen whenever you are tempted to call something a representation, or to espouse a representational view of sense perception. 

Thanks for the stimulus. Recently Bill Lycan gave a talk at Otago on whether sense content was intentional, taken to mean representational, and I have been arguing with him about that dubious equation.  Thanks, Annette Baier


2010-04-05
The time-lag argument for the representational theory of perception

Post script: Of course I meant "impression of reflection," not, as I sloppily wrote, "reflective impression," for what Hume called our emotions. And for all I know there is some time lag in our emotional responses to things--certainly there was in my felt need to correct what I had written. Annette Baier  


2010-04-09
The time-lag argument for the representational theory of perception
Second P.S. And of course I meant "specious present." A.C.B. 

2010-04-09
The time-lag argument for the representational theory of perception
Reply to Stevan Harnad
"(9) Perception is not "direct"; it merely feels direct -- but that's apparently good enough for government work."

Stevan, as one who works for the governement I have to say I agree. The truth is, if we didn't have time lags built in to the present, we would not see the present let alone the past or the future so the argument itself would not exist.  Cognitively the argument is we can only see so much of the true brightness of the sun because our pupils contract and can only see so much of the darkness of the night because they can only dilate so much.

2010-04-09
The time-lag argument for the representational theory of perception

Hi

I find this argument and the debate very interesting as I am actually thinking about related issues at the moment.

It appears crucial here to get a clearer concept of ‘direct experience’.

If direct experience requires that what we experience exists simultaneously with our experience of it, then, assuming as I do that premise one is true, there might be a problem on all metaphysical views on time, presentism and eternalism alike.  However, this appears to be rather a hidden premise that has to be argued for.

I wonder whether one could not just say that a direct experience is one that we are having when we are in perceptual contact with an object. As a matter of fact, one might then add, perceptual contact between experienced object and experiencer is a transtemporal relation: its relata are located at different times.  This interpretation of what a direct experience is then is still a problem for presentists, because one of the relata does not exist anymore.  The eternalist though could say that  we are having a direct experience when we are in perceptual contact with an object located in the past, and we are aware of the content of our experience as presently occurring, but actually, due to the time lag, what we experience as present is necessarily past.  I agree here with many previous contributions that, if we can reject the idea that direct experience involves simultaneity of experienced object and experience, the eternalist has no problem.  

 However, two questions arise from this:

 (1) Can we reject the idea that direct experience involves simultaneity of experienced object and experience? And if so, that is,  if direct perception is merely being in perceptual contact with what has occurred a little time ago, this time being the duration of the time lag, then what would be an indirect experience?

(2)What could a presentist say?

If anybody has some answers, that would be helpful.

Thanks,

Akiko.


2010-04-09
The time-lag argument for the representational theory of perception
Dear Derrick, So this is the nub of the problem. We grow up tending to think our 'experiences of the world' are just the world - what we might call naïve direct realism. If we study perception (just being at a lecture by Ken Aizawa will do fine) we come to understand that the dynamic processes reliably and immediately (without mediation or further dynamic mechanism) associated with our experiences are not processes in the outside world but processes in our brains. Perception is indirect in this sense. However, the next hurdle to get over is what we might call naïve indirect realism. This is the idea that our experience is an internal 'model' or simulation or presentation of some 'things' in the outside world of a similar ontological category to the experience. Thus, we might wonder if the 'real world' is actually larger or slower (or in your case earlier) than it seems to us, or that colours in the real world are more like sounds. This is just as wrong, which may be why some philosophers have felt justified in going back to direct realism.

We have no evidence for an 'actual outside world'. Kant said it would be unknowable but I would not dismiss it on positivist grounds. We have no reason even to consider it and physics shows that it is not there. What we have is something different. We have evidence of what I find easiest to describe as 'what is really going on'. What we have evidence for is a dynamic universe consisting of instances of operation of dynamic laws of disposition to generate experience. These instances of operation of laws exist in no other sense that we have any idea of than as dispositions to determine experiences, but in that sense we have overwhelming evidence that they exist. Mass, charge, spin, length and duration are all parameters of these instances of operation of laws, contributing in various ways to dispositions to generate experience. They are concrete in that they are instances. However, they are unenvisageable, having only dispositional rather than qualitative properties. Berkeley was right in many ways but wrong if he believed that this universe only existed in the minds of humans. Before we evolved the dynamics were really going on and had real dispositions to entrain more dynamics with more dispositions, that would tend to lead to experiences if tested with a subject today.

The key point is that experiences and the instances of operation of dynamic laws that determine experiences are quite different types of entity. In simple terms they are actualities and potentials for change of actuality. They exist in quite different senses; the counterintuitive nature of their dichotomy presumably fuelled the writings of Parmenides, Heraclitus, Zeno and others. We have no evidence of any 'stuff', only real (in one sense) experience and real (in another sense) potentials for experience. This does not mean that there are two sorts of reality in a dualist sense, merely that we use the word 'real' to describe the world in two different ways that effectively 'cut at different joints'. If we conflate the two uses we end up with the sort paradox we are discussing.

To my mind this is all bog standard science. I suspect it was always appreciated by the real innovators in science but it takes effort to get used to so many practical scientists continue happily in naive realist modes. However, quantum theory makes it transparent that the mass, length and time of physical laws are merely parameters of dispositions that behave in a way that is incompatible with their being simultaneously actual. Relativity debars an actual universe because there is no such thing as simultaneous existence. Actuality and potentiality are incommensurable. The time of one is completely different from the time of the other. One time is a quality of experience and the other is part of a dynamic metric.

So in the end it becomes clear that 'experiences of the world' still has within it a category mistake. These are experiences determined by the world of what is really going on. They are not 'of the world' in the intuitive sense. I would agree that the word 'representation' may be sufficiently elastic to be usable, and indeed I have used it at times. Presentation might seem preferable but may encourage the category mistake more. What worries me most is simulation.

I hope that gives an idea why I think the two options offered are both untenable. 

Best wishes

Jo E

2010-04-09
The time-lag argument for the representational theory of perception
Reply to Luke Culpitt
Hi Luke

Thanks very much for your response.

You write:
I wonder what becomes of "the present" if this argument is true.
I don't think the argument actually has any implications for what we mean by the present - the present is just the current instant, regardless of whether what we are experiencing, perceptually, in the current instant is the world of the current instant or a mental representation of a past instant.
... I'm unsure why "what one directly experiences, visually, when one looks at the world cannot be the world itself". What would it be a visual experience or representation of, if not the "world itself"?
The last step doesn't say that our vision isn't an experience of the world, but that it is not a direct experience of the world. That is, it is stating that our vision is an indirect experience of the world, because it is merely a mental representation of the world.

Re your questions about the use of the term simulation, a simulation of reality can be 100% accurate or completely fictional, or somewhere in between - all that matters is that the person experiencing the simulation thinks that they are directly experiencing reality. For example, consider dreams. In the case of perception, I would say that the simulation is generated from the processing of visual information, and is sufficiently accurate for us to interact fairly successfully with the world.
I don't disagree that there is a time lag, but I see it as a time lag which is necessary in order for us to have "direct experiences".
But if you agree that the content of your perceptions in the present is the world of the past, and also agree(?) that the world of the past cannot itself exist in the present, by definition, then this seems to me to lead inevitably to the conclusion that what you directly experience, perceptually, cannot be the world itself, and therefore must be merely a mental representation of it.
I think part of the problem here may be your assumption that a "direct experience" must occur in the "objective present" (when light hits the retina). That is, it could be that what we usually mean by "the present" is not the "objective present". I have merely presumed here, following you, that the "objective present" is when light strikes the retina. However, I take it as generally accepted that the present moment is indexical, and is therefore defined by the time at which we are conscious, even if our consciousness is of events which occurred 0.1 seconds in the past of some "objective present".
I would say that the 'objective present' is the only present, and is simply defined as the current instant (which may or may not be when light is hitting the retina). I think the concept of the present is completely independent of the perceptual process and perceptual experience. The present would still exist even if we didn't.

With best wishes

Derrick


 

2010-04-09
The time-lag argument for the representational theory of perception
Reply to Mohan Matthen
Hi Mohan
As Jim Stone said earlier in the thread, perhaps you are assuming presentism -- the view that past entities no longer exist in any sense at all.  But that's a pretty radical view with many counter-intuitive consequences.  For example, it has the consequence, barring desperate remedies, that it is not now true that Caesar once crossed the Rubicon. 
I think it is important to distinguish between things in the past and facts about things in the past. I'm saying that the past doesn't exist in the present, by definition. In the case of Caesar, I would indeed say that both the man himself, and his crossing of the Rubicon, are things which no longer exist in any sense at all. I don't think that this is a radical position - it doesn't contradict any statement about the existence, in the past, of Caesar, and the occurrence, in the past, of his crossing of the Rubicon.
Do you want your theory of perception to rest on a metaphysical thesis of this sort?  I would much rather argue for representationalism on cognitive-science grounds ...
I don't actually think of the argument as being metaphysical - to me, it's just an argument about the nature of perception which relies on basic knowledge about both the perception process and the nature of the past and present. However, a cognitive science argument would be preferable in that it would be a more direct argument, if you'll excuse the pun.

With best wishes

Derrick









2010-04-09
The time-lag argument for the representational theory of perception
'I would indeed say that both the man himself, and his crossing of the Rubicon, are things which no longer exist in any sense at all.'

This does sound like presentism. If we understand you. It is indeed a radical view, exceedingly controversial and widely rejected, though
it is certainly widespread outside of philosophy and physics--the 'ordinary person's' view ('the past is no more, the future is yet
to be, only the present is real').   Multiple objections to it, in fact. There are some presentists left, but nobody is in a position to help themselves to it as a premise
in an argument.
 

2010-04-14
The time-lag argument for the representational theory of perception
Reply to Jim Stone
[I should say, as the originator of this thread, that I can only post twice in 24 hours, because I don't have 'pro' status, and I won't necessarily respond to posts in order, although I am intending to answer all posts.]


Hi Jim

You write:
nobody is in a position to help themselves to it as a premise in an argument
Anyone is free to construct arguments using whatever premises they want - whether others accept the premises used is another matter.
It is indeed a radical view, exceedingly controversial and widely rejected ... Multiple objections to it, in fact.
The same used to be true of the view that the Earth orbits the Sun and not vice versa.

Even opponents of presentism don't believe that the past and future exist in the present. They believe that the past and future exist 'out there' in time, whether behind or ahead of our current 'location' in time, in the same way that an object exists out there in space, whether in front of us or behind us. That is, whereas the common view of time is that the contents of the past exist merely in our memories and physical records, opponents of presentism would say that Caesar, for example, literally exists in the past - but they wouldn't say that Caesar exists in the present, in any sense whatsoever. And so they wouldn't disagree with step 3: 'The past, however recent, cannot itself exist in the present, by definition, although a representation of it can.'

Derrick

2010-04-14
The time-lag argument for the representational theory of perception
Hello

I unfortunately don't have time to reply to all the posts above, but I've found them all very interesting and valuable.

While I don't believe that the objections raised so far are valid, I've been trying to think of a way of re-presenting the argument (!) in order to side-step them. I'd again be very grateful for your feedback:

1) Your vision is dependent on visual information travelling from your eyes to the visual areas of your brain, and then being processed, all of which does not happen instantaneously, but takes a finite amount of time, however small.

2) Therefore, the content of your vision lags behind events that are occurring in the scene in front of your eyes, however slightly.

3) If the content of your vision lags behind events occurring in the scene in front of your eyes, then the content of your vision cannot be literally the same thing as the scene in front of your eyes.

4) Therefore, what you directly experience, visually, when you look at the world cannot be the world itself, and must instead be merely a mental representation of it, generated by your brain from the information that it receives from your eyes.

As I stated at the beginning of this thread, given that the visual lag is about 0.1s, someone walking in front of you at a relatively slow pace of 1 metre per second will have actually travelled about a further tenth of a metre from where you perceive them to be at any moment. Likewise, a car travelling at 10 metres per second - about 22 miles per hour - will have travelled about a further metre from where you perceive it to be at any moment.

Derrick







2010-04-14
The time-lag argument for the representational theory of perception
I've made step 3 more concise:

 
1) Your vision is dependent on visual information travelling from your eyes to the visual areas of your brain, and then being processed, all of which does not happen instantaneously, but takes a finite amount of time, however small.

2) Therefore, the content of your vision lags behind events that are occurring in the scene in front of your eyes, however slightly.

3) If the content of your vision lags behind the scene in front of your eyes, then they cannot be literally the same thing.

4) Therefore, what you directly experience, visually, when you look at the world cannot be the world itself, and must instead be merely a mental representation of it, generated by your brain from the information that it receives from your eyes.




2010-04-14
The time-lag argument for the representational theory of perception
A quick point in relation to Stevan Harnad's analysis. Experience is, as far as I can see, just input. Its content may or may not (e.g. locked on, paralysis during anaesthetic induction) reflect the operation of motor servo mechanisms but in itself it is input. For X to experience Y, I think Y must influence X. If X then has an output in terms of influencing Z that influence on Z cannot be part of X's experience, except through some subsequent input. I cannot see how experience can be input/output. In ordinary operational terms it is certainly not what we mean by experience (Somerset experienced heavy snowfalls). The functionalist suggestion that experience is determined by I/O or 'role in the world' appears to be based on a misconceived externalist argument. So I think the issue about timing of input stands.

2010-04-14
The time-lag argument for the representational theory of perception

Dear Jonathan,<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

Doesn’t the brain compensate for the time-lag? We know that the brain uses all sorts of background information, learned or inherited, in making sense of the skimpy information it receives from the senses, and we know it also tries to put things right when the information it receives seems abnormal in some way (so, e.g., we ‘see’ a picture of a whole face when we are actually presented with a picture of half a face in one-half of the visual field). So if we see an approaching object, perhaps the visual information is adjusted by the brain to take account of the 0.1 second time-lapse, so that we see a representation of where the object is (or ought to be) rather than where it was 0.1 seconds ago. I have a vague (and possibly mistaken) recollection of reading something like this in a book on the brain.

 

You say that: 'Directly experiencing the world' turns out to be a pseudodynamic folk concept that cannot be explicated without self-contradiction.

 

I suspect you are right, but I would like to see the self-contradiction spelt out.

 

You say: There is no 'stuff' out there that our experience 'simulates'. Such an idea is as self contradictory as the direct perception one and modern physics shows empirically that it is invalid.

 

Again, I would like to see the self-contradiction spelt out. And what bit of physics are you referring to?

 

Best wishes,

 

Danny


2010-04-14
The time-lag argument for the representational theory of perception
Hi, all of you who are worried about time lag, I recommend R le Poidevin on the specious present, in the Stanford Encyclopedia. William James took the concept fro. a psychologist Kelly (or Clay) and he thought it lasted between 2 seconds and one minute, but the latter seems too long for us to think of as present all together. For the perception of change and motion, we must be aware of an interval, even if there is a time lag. But if we are aware of intervals, we could be aware of the time from the impinging of light rays on the retina till the information is processed, all of that interval seeming present to us. But I am mot a presentist, merely a believer in presentation as well as re-presentation, and one who thinks there is no veil of perception, that sense perception is as direct as we get to what is outside us. Annette B. 

2010-04-14
The time-lag argument for the representational theory of perception
Hi Derrick,

"I don't think the argument actually has any implications for what we mean by the present - the present is just the current instant, regardless of whether what we are experiencing, perceptually, in the current instant is the world of the current instant or a mental representation of a past instant."

You appear to equate the present moment with the time at which light hits our eyes (before being processed and perceived/experienced). But why should we accept that this is the present moment? Why not, instead, at the time that light is reflected from its object/s, or somewhere in between, or even before that? On the other hand, I am saying that the present moment is the moment at which we are conscious/perceiving/experiencing, regardless of the content of our perceptions. To use your terms, I am saying that the present moment is after the processing "lag", and is the time at which we are (at which we find ourselves) conscious. You don't seem to disagree with this placement of the present moment, when you say that "the content of your perceptions in the present is the world of the past". The issue I have with this is that "the world of the past" implies that the present moment is not now when I am perceiving, but earlier when light hit my eyes. But again, what grounds do we have to consider this moment prior to perception as the present moment, such that the content of our present perceptions can be said to be of "the world of the past"? This is the implication for the present with which I am concerned.

"The last step doesn't say that our vision isn't an experience of the world, but that it is not a direct experience of the world. That is, it is stating that our vision is an indirect experience of the world, because it is merely a mental representation of the world."

If our vision only counts as an "indirect experience of the world", then what could possibly count as a "direct experience of the world"? What difference can you discern between a "direct experience of the world" and a mere "mental representation of the world"? Presumably, a direct experience is one which involves no time lag between light hitting our eyes and our perceptions, but this would not allow for any experience at all, assuming that some brain processing is required in order for us to have conscious experiences. The implication is that a direct experience can only ever be had with the so-called lag. Also, I'm unclear on what an "indirect experience" could possibly mean. If all experiences must be indirect, then what purpose does the distinction between "direct" and "indirect" serve?

"But if you agree that the content of your perceptions in the present is the world of the past, and also agree(?) that the world of the past cannot itself exist in the present, by definition, then this seems to me to lead inevitably to the conclusion that what you directly experience, perceptually, cannot be the world itself, and therefore must be merely a mental representation of it."

Again, if this is true, then what would count as a direct experience?

Luke.

2010-04-14
The time-lag argument for the representational theory of perception
To clarify, 'you cannot help yourself to P as a premiss' is philosopher-speak for 'if you include P as a premiss you will need to support it.'

We weren't clear whether presentism really is an (implicit)  premise in your argument, but it seemed it might be.
You can of course construct any argument you please. If presentism is in it the argument depends on a highly
controversial premise that will need substantial defending if your argument is to persuade the
audience you have in mind. .

As I see it, the difficulty in your argument (s) is the inference to 4, which appears invalid. IF presentism
plays a role it is in supporting that inference. Best, Jim

2010-04-19
The time-lag argument for the representational theory of perception
Reply to Tone Haugen
Hi Tone

This is the link:

http://www.chainsofreason.org/this-is-a-simulation-1

With best wishes

Derrick

2010-04-19
The time-lag argument for the representational theory of perception
I'd like to address two of the main objections being made.


- The first main objection is that step 3 in the first version of the argument, at the start of this thread, assumes presentism, and presentism is highly controversial and has very little support.

However, I think that step 3:
The past, however recent, cannot itself exist in the present, by definition, although a representation of it can.
is compatible with both presentism and eternalism.

Presentism states that the past and future don't exist in any sense whatsover, and so the above statement seems to be clearly compatible with presentism.

However, while eternalism states that the past and future do exist, it states that the future (relative to our current point in time) exists in the future, and the past (relative to our current point in time) exists in the past. For example, in the case of the future, eternalism states that the future is 'already there' - but it doesn't state that the future is 'already here'. In the case of the space dimension, an object located behind or in front of you exists, but an object in front of you exists in front of you, not at your own location, and an objection behind you exists behind you, not at your location. Just as we wouldn't say that an object behind or in front of us exists at the same location as us, in any way whatsoever, so eternalism doesn't say that the past and future exists in the present, in any way whatsoever.

Therefore, the above statement is as compatible with eternalism as it is with presentism.

And if the world of the past cannot exist in the present, but the content of our vision in the present is the world of the past, then what we directly experience, visually, cannot be the world itself, and must be merely a mental representation of it.


- The second main objection, which applies also to the second version of the argument, is that at least some aspect of our visual experience begins with light striking the retina.


This raises two questions:

1) Which specific aspects of our visual experience are caused simply by light striking the retina?
2) What is the mechanism for this event having an effect on our vision, given that at that point the information contained within the light has not reached the brain, nevermind been processed?

While we certainly wouldn't see at all if we didn't have eyes, so we equally wouldn't see at all if we had eyes but no brain. Therefore, the brain has to have a part in every aspect of our visual experience, whereas the above objection implies that there would at least some form of visual experience if your brain was removed but light was falling on your retinas.


2010-04-19
The time-lag argument for the representational theory of perception
I agree with Jim that Derryck's step 4 is a non sequitur, since a representation must re-present, and the information we get in sense perception is there for the first time, even if what it presents is a slightly past state of the world. What does follow is that the interval of world-process we get in sense perception is even more speciously a present state of the world than Williman James thought. He thought what we experience as present always includes some past time, but your argument seems to show that the states of the world sense percetion reveals are all past, by the time we perceive them. But we are perceiving them, not representing them, as we do later when we think about past perceptions. So what anyway, if our version of the world is slightly dated? If the past is the real past, not a fictional one, we still are getting the truth about the world. What I find slightly odd is if my awareness of my emotions is fully up to date, while my version of my visual field is a little out of date, especially if my current emotion is wonder at the red sunrise. The wonder may be really in the present, but the sunrise it reacts to is only speciously in the present. Only my meta-wonder at my wonder is fully in this moment. We oldies live in the past anyway, leaving to you younger ones to do your best to live in the present. (And why am I the only woman in this conversation?)    Annette B.

2010-04-19
The time-lag argument for the representational theory of perception
Reply to Luke Culpitt
Hi Luke

You wrote:

You appear to equate the present moment with the time at which light hits our eyes (before being processed and perceived/experienced).

The argument doesn't define the present in terms of any stage of the visual process. The present is simply now, regardless of what is happening now. That is, the present is indeed the moment when light hits the eye if that is what is happening in the present moment. But the present might also be the moment when a particular event in our visual perception occurs if that is what is happening in the present moment.

If our vision only counts as an "indirect experience of the world", then what could possibly count as a "direct experience of the world"?

If what we directly experience, visually, is merely a mental representation of the world, then this is an indirect experience of the world. If what we directly experience, visually, is the world itself - which is most people's understanding of vision - then this a direct experience of the world.

Presumably, a direct experience is one which involves no time lag between light hitting our eyes and our perceptions, but this would not allow for any experience at all, assuming that some brain processing is required in order for us to have conscious experiences.

This is the fundamental problem with direct perception which the argument is highlighting. The argument shows, in my view, that the perceptual lag makes direct perception impossible, and yet the perceptual lag is clearly an unavoidable fact of the perceptual process.

Derrick

2010-04-19
The time-lag argument for the representational theory of perception
Hello again,

 The argument appears to be that, because it takes an amount of time (no matter how small) for "visual information" to reach the "visual area" of one's brain one can never experience the world directly, and such a conclusion seems to be a reductio of the argument. It is a bit of a stumper, but the argument, on the face of it, reminds me of one of Zeno's paradoxes - achilles and the tortoise. In this paradox, Achilles can never beat the tortoise in a race if Achilles agrees to give the tortoise a head start, because firstly, Achilles would have to traverse half the distance between himself and the tortoise, but before he could traverse this distance, he would have to traverse a half of this distance and so on ad infinitum. Consequently, Achilles can never beat the tortoise. I realise this paradox is not exactly of the same form as the time lag argument but there may be some way of comparing them to find a way out? For instance, one could make an analogy between "Achilles will never catch the tortoise" and "There will always be a gap between the world as it is, and how (or when) one sees it". The conclusion of the Achilles argument is seen as a reductio of the argument itself, one of the premises must be wrong if it leads to an obviously absurd conclusion, and perhaps a similar result could be inferred from the time lag arguments conclusion. One of the dubious assumptions
in Zeno's argument that led to the conclusion, is that time and space are infinitely divisible. Perhaps a solution to your argument is something along the lines of - there is a time gap but this does not mean that our perception of the world is not direct/instantaneous? This is all very sketchy and ill thought out, I realise, but the similarity between the two arguments seemed very relevant to me but it may turn out to be merely that - a similarity.

Best Wishes

Garry 

2010-04-19
The time-lag argument for the representational theory of perception

Dear Danny,

The brain is good at collating sensory inputs to compensate for neural path lengths and generate a coherent narrative. However, I know of no evidence that the brain 'presents things to experience' where it guesses they will be in 0.1 seconds and it does not seem plausible. If a bird flies up to a tree we do not see it appear the other side and then vanish (because in fact it flew into a nesthole). Initiating movements on the basis of predicted need is a different matter (we feel our movements respond in the right time frame because our sense of our movement is also subject to lag). I do not think any of this is relevant to Derrick's point that the relationship between our experience and what is going on in the world is indirect. It reinforces the view that experiences are mediated by internally constructed patterns.

The contradiction in 'directly experiencing the world' is quite well put by Luke Culpitt. 'I experience the world' can be just a statement of a given datum. 'I directly experience the world' invokes a language of process or dynamics, contrasting with 'indirectly', but in all the senses of dynamics I can think of experience is indirect. If direct means without intervening steps then it must be indirect because the world is not touching my cerebral cortex. If direct means 'without being presented in a way dictated by the pathways of informing' again it must be indirect because the informing consists of nothing more than these pathways. (If this were not so and 'the true quality of an object O' is carried through events P, Q, R and S to ourselves we have a problem of infinite complexity because we should get the true quality of every linked event P, Q, … A, B, …  and back to the Big Bang as well.)

Another possible meaning of 'direct' is that it does not involve a 'second transduction' in which information carried by light and synapses is 'converted back' to 'sense data' to be experienced. This relates to the flawed argument about infinite regress with homunculi. There are in fact (pace Dennet) a very large (but not infinite) number of transductions. The mistake is to ascribe to any of these some special ontological category of 'sense data' that 'simulates' 'outside stuff'. If the world, inside and out, is made of the same sorts of dynamics generating actualities, as is simplest to suggest, then these extra categories are redundant.

Moreover, experience simulating outside stuff hits a contradiction because experience is an actuality involving a datum or given, so must be from the viewpoint of that to which the datum is given. Any equivalent in the outside world would also need to be an actuality based on a datum to something. But 'stuff' is a folk concept falsely divorced from viewpoint. In a rational analysis the only account we can divorce from viewpoint is dynamics. The whole point of physics is to build this viewpoint-free dynamic account. The price is that dynamics are unenvisageable and only simulable by more unenvisageable dynamics - envisaging is always from a viewpoint, even if we can employ several levels of envisaging involving 'thicker' or 'thinner' qualia.

So the dynamics of what is really going on when 'a ball bounces on a table' can give rise to an actual experience of a ball bouncing on the table for me. These dynamics also give rise to countless actualities of interaction between ball and table and components thereof but none of these will bear any resemblance to 'a ball bouncing on a table' in any sense simulated in my experience. The actuality is totally dependent on the pathways by which the 'given' arrives and these will bear no relation to mine.

 The empirical refutation of 'actual stuff out there' comes from both QM and relativity. In modern (QM) dynamics a pure dynamic system (the operation of a single set of dynamic rules between two actualities of measurement) can only be considered as a whole, involving extended time and space. There are no actualities along the way - the principle of superposition. This only seems strange if we make the mistake of equating actuality with dynamics in the first place, whereas the two are mutually exclusive. Relativity debars simultaneous existence of separate events because time t for one object does not equate to any one specific time for any other event. Again, the idea of simultaneity is a folk mistake based on conflation of actuality and dynamics.  


2010-04-19
The time-lag argument for the representational theory of perception

I think I broadly agree with Annette Bairer, and I'd like to suggest a very different approach to the idea that we don't have visual experiences with intentional content.  (Which is not to say that I don't like hers, and I think her insistence that we don't have representations with presentations indicates the  extent to which we've taken on board a technical way of speaking that may not be sufficiently examined.)

Here's the problem: 
Background:  we are products of evolution and our visual system is supposed to enable swift and broadly accurate reactions in our niche.  It really seems not designed for our uttering small truths about the details, at which in fact we are actually quite bad.  Getting the details right is very energetically expensive; we are much more gist creatures.  Now stuff like the time-lag is utterly irrelevant to our evolutionary success as long as we're in our niche; maybe in a possible world with changes that are much faster, we'd count as too slow to last as a species,  but that's not us in our world.  Further, we can and often do react to many different elements in the visual process before we get to the stage of perceptual organization and object identification. 

The crux:  talk about "the visual experience and its representative content" may well not be needed to describe how  vision, when functioning well, helps us in our niche.  Further, descriptions of the so-called perceptual experience tend to buy into the false "photograph-of-the-room" picture of perception.  Finally, incorporating the idea of representations, with reference and truth-values, incorporates interests  (e.g., in truth) and models (e.g., linguistic) that are  pretty foreign to what vision evolved to do. 

Or to put it briefly:  the time-lag looks like a problem only if we incorporate optional models and interests.  It shouldn't be  used as a reason for incorporating them.  That gives us a kind of circularity that makes mistakenly representationalism inevitable.

To explain:  if there's that problem, we need representational content, but that's because the notion of representation content creates the problem.


2010-04-19
The time-lag argument for the representational theory of perception

Jonathan&Danny:

Actually, there is some good evidence that the brain predicts how things are *now* based on inputs that came in a short time ago, coming from work by Mark Changizi.   (Anne: these short time-lags, it turns out, *are* relevant to our niche!)  For an overview of this work, see his (2008) "Perceiving the Present and a Systematization of Illusions", Cognitive Science 32(3): 459-503.  (There's also a brief presentation here: http://changizi.wordpress.com/2010/01/11/why-we-see-illusions-in-four-slides/ .)  It turns out that this hypothesis systematically explains an impressive number of visual illusions.

This suggests a different argument against direct perception, that doesn't rely on something like Derrick's controversial premise (3).  Something like:

1) If a veridical perception is direct, it presents a particular event, E.

2) For a veridical perception to present a particular event E directly, event E must be causally implicated in actions based on that perception.

3) In some cases of veridical perception, no particular event E presented by the perception is causally implicated in actions based on that perception (from Changizi's "Perceiving the Present" results).

---------------------------------------------------------------------------------------------------------

Therefore at least some veridical perceptions are not direct.

Direct perception theorists think that the content of your perception just is some particular event (probably complex).  That event should then be one of the causes of actions based on that perception.  Changizi's results suggest that, at least sometimes, we act based on what our brain predicts is the current situation from inputs about how things were out there a moment before.  If we act quickly, then, our action is caused by events in the past, not any current event that our perception presents.  (I'm assuming it isn't plausible to say that the perception directly presents those past events - that's not consistent with introspection or psychophysics.  This is where my argument has an advantage over Derrick's.)  

On the other hand, when we act slowly, inputs from event E have time to arrive and confirm the brain's prediction, thus making E causally relevant to the action. So the case is shakier against the direct perception theorist when we act slowly.  Of course, you might try to remove the dependence on action from the argument, but then you seem more likely to get tied up in knots over the specious present.  But maybe you folks can soup this up in some other way to make the conclusion stronger.  (And apologies if I'm ignoring something that's already come up - I confess I haven't read this huge thread in its entirety!)

Dan


2010-04-19
The time-lag argument for the representational theory of perception
'What I find slightly odd is if my awareness of my emotions is fully up to date, while my version of my visual field is a little out of date, especially if my current emotion is wonder at the red sunrise. The wonder may be really in the present, but the sunrise it reacts to is only speciously in the present. Only my meta-wonder at my wonder is fully in this moment. We oldies live in the past anyway, leaving to you younger ones to do your best to live in the present. ...    Annette B.'

Such is life....

2010-04-19
The time-lag argument for the representational theory of perception
On the contrary, Dan.  I said that the time lag is irrelevant to our success in our niche.  In fact, I think I  said  that it is utterly irrelevant and I probably should have said that it is largely or almost entirely irrelevant to our success.  I should also have made explicit the assumption that the "we" have "normal" vision. 

That's not to say that the time lag isn't noticed by our visual system, or that it is irrelevant to our understanding of how vision works.  There's are general coordination problems the nervous system has to solve to put data from  different sensory sources together, since  there will be different time lags involved.  Further, we do know is that there circumstances requiring action where the time-lag could cause problem, if  there weren't compensations for it.  The frog does not aim at where the  fly was, but, hopefully, at  where it is now.   I take it that's what Changizi is talking about when he  says, "The detection of these empirical regularities was motivated by a hypothesis, called "perceiving the present," that the visual system possesses mechanisms for compensating neural delay during forward motion."

It's also possible to tease apart the compensations so that we make mistaken judgments; e.g., the flash-lag effect.  So the time lag can cause problems in labs.  I think that  also there may be some concerns with its causing problems in highly complex technical environments, but that's arguably not a niche problem.  Still, frogs may be stuck if flies get a lot faster, and perhaps the time lag effect explains in part why some athletes seem unbeatable.  So I shouldn't have said "utterly." 

Still, I think it is very significant that it does not cause a problem with anything like the generality of the epistemic problem that remains when we notice that Changizi's perceiving the future seems to be restricted to forward motion.  The point I'd like to suggest is that it should be a mistake to let epistemic problems create the categories  in terms of which we should describe what well functioning vision is - that is, the categories that (I've argued elsewhere) should be used in understanding vision.

2010-04-21
The time-lag argument for the representational theory of perception
Reply to Anne Jacobson

Hi Anne,

Sorry - I agree with you that the time lag isn't very relevant to success in vision-based action.  Not very relevant, that is, given the adaptations in our visual systems, which do a great job of compensating.  All I meant was that the fact that there *are* those adaptations shows that the (uncompensated) time lag is relevant to success.


2010-04-25
The time-lag argument for the representational theory of perception
Hi Annette

You wrote:

I agree with Jim that Derryck's step 4 is a non sequitur, since a representation must re-present, and the information we get in sense perception is there for the first time, ...

I think that the proposed mental representation is indeed a re-presentation - it's a mental re-presentation of what was physically presented to the eyeballs 0.1s earlier. The information that a digital camera receives is received by the camera 'for the first time', but the image on the screen on the back of the camera is still a re-presentation - it's a re-presentation of the information presented to the lens of the camera a fraction of a second earlier.

So what anyway, if our version of the world is slightly dated? If the past is the real past, not a fictional one, we still are getting the truth about the world.

True, although a photograph provides truth about the scene that was in front of the lens, but it is not that scene itself, but a representation of it.

Best wishes

Derrick

2010-04-25
The time-lag argument for the representational theory of perception
Reply to Garry Todd
Dear Gary, I think your comment is very relevant. Zeno is one of the key sources for the point I was making about naive indirect realism. The value of Zeno's paradox is not much about the infinite divisibility of time and space. It is that it shows that the dynamic world cannot be just a sequence of actualities. If we try to explicate dynamics in terms of envisageable static actualities we hit a paradox. The solution is to realise that we should never have thought we could do this in the first place. Change and actuality are mutually exclusive complementary concepts. 
So the message is not, as you might seem to suggest, that Zeno allows us to fudge a time gap into an instantaneity. It is that there is no time gap between an outside actuality and in inside simulation thereof because there is no outside actuality of that sort (see my reply to Danny). The question 'do we experience what the world is like now or what it was like before' is based on a false assumption. The outside dynamic world of what is really going on is not 'like anything' in that sense. We gain information about what is really going on and inevitably it takes time to acquire that information, that's all. The entire vocabulary of modern philosophical debate on this is, I think, misguided. It bears no relation to physics and it does not do justice to the insights of the past going back to Presocratics. Leibniz has a clear account if you already know the point he is making but unfortunately he is opaque if not.
As an aside in relation to above posts the 'duration' of the specious present is not a duration in a dynamic sense. Experiential time is probably encoded in a combination of dynamic space and dynamic time (as some form of differential). Events in a brain lasting 20msec can encode a sense of a whole tune, a symphony or the passing of the years. There is absolutely no need to be puzzled by this because experiential time and dynamic time are totally different aspects of the world - not even similar enough for one to simulate the other. That is what Zeno was telling us.

2010-04-25
The time-lag argument for the representational theory of perception
Reply to Anne Jacobsen.
Hello Anne, and so sorry to have missed your contribution before. What you say about our niche, and the way we anticpate the near future, as do the frogs, makes good sense. Would you other represenationalists say we represent the future, when we make predictions? If so, you misuse the Englsih language. With both what we take to be present, in sense perception, and what we take to be future, there is no "re" in whatever is before our minds--its there for the first time, unless of course we had earlier predicted the present input, in which case even I would allow it to be, to some degree a "re-presentation."Only to some degree since we are unlikely to have forseen the full version of the present percept, only some aspects of it. And it is, even if a bit out of date, still a Humean "vivacious" impression, with the full dense complement of details, with what Descartes in the Sixth Meditation called their vividness, and "express-ness," even a sort of distinctness, even when they lack the clarity and distinctness of intellect's best products. It is what verifies predictions, and gives us the materials for ideas which represent some aspects of its rich content. But I am repeating myself, Annette B. 

2010-04-25
The time-lag argument for the representational theory of perception
Reply to Dan Ryder
Dear Dan,The Changizi idea does not seem to have much to do with compensating for the neural path lag, more to do with the complex specious nature of 'now' and its pervasion by kinaesthetic context, as indicated by scores of pages of James. The path lag is a constant but the modulation of the sense of present by motion will be variable. At least we are, I guess, agreed that it supports Derrick's basic premise that there is nothing direct about perception. I would be wary of implicating actions in any analysis of perception, which I think has to work in the absence of any action. I would agree with Derrick that the issue is much simpler. Direct is a non-starter. My caveat was that indirect, qua simulation, won't do either in the only ontological position that modern science leaves open to us.

2010-04-25
The time-lag argument for the representational theory of perception
Hi Derrick, and thanks for the response.

"The argument doesn't define the present in terms of any stage of the visual process. The present is simply now, regardless of what is happening now. That is, the present is indeed the moment when light hits the eye if that is what is happening in the present moment. But the present might also be the moment when a particular event in our visual perception occurs if that is what is happening in the present moment."

We appear to agree that we are perceiving in the present moment. We also seem to disagree over whether the content of those present perceptions is of the past or of the present. You say they are of the past, while I say they are of the present. If the content of what we perceive in the present is the "world of the past", then does this mean that we can never have (direct) perceptions of the "world of the present" - that the present is forever out of our perceptual grasp? But wasn't the present the time at which we are having perceptions, anyway? Instead of the present minus the lag time?    

2010-04-25
The time-lag argument for the representational theory of perception
Reply to Garry Todd
Hi Gary

What you say is interesting, but I'm personally generally not a fan of using arguments by analogy or reductio ad absurdum arguments. I think there is no substitute for tackling an argument head-on and identifying the flawed link, or links, in the chain of reasoning.

Best wishes

Derrick

2010-04-25
The time-lag argument for the representational theory of perception
Derrick,

I generally agree with what Anne Jacobson has said here, and I think a couple of the points I made in my first post were perhaps better expressed in hers.  One point I made is that perception does not involve a perfect replication of the objects we perceive.  So, even though my perception of event X may occur at some point after event X begins (a fact true of all perceptions of events except perhaps for those events which are constituted by direct interaction with our organism), event X may continue during my perception of it, and the information which constitutes my perception may not differ significantly from any present (here and now) facts about event X.  In other words, the time-lag does not necessarily create a disparity between the here and now and the content of the experience of the here and now, even if experience is a presentation of that reality.  The time-lag would only be significant for those events which occur at relatively high speeds.

More generally, part of the problem I see, and which I tried to point out earlier, is with the notion of experience.  There is a temptation to say that experience occurs some time after the brain has done some work.  Of course, the eyes do work, too, and can be considered functional parts of the brain.  (Where do you draw the line between the brain and nerves, if you draw one at all?) When the eyes interact with light, this is the beginning of the brain's (or neural system's) interaction with the world.  The question then is whether or not this first level of interaction constitutes some level of experience.  This is not an easy question, but it appears that the eye does have some functional characteristics which are capable of constituting some level of experience.  Consider that the eye has been likened to a sort of camera.  It has also been observed that the eye is not what we would consider a very good camera--but, then, the role of the eye in our perceptual system is not the same as the role of a camera in our daily life.  I do not think we should exaggerate the similarities between eyes and cameras, or judge one by standards we use to judge the other.  The point is only that the eye is capable of capturing or presenting images, and this can constitute one level of perceptual experience.

Thus, in my earlier post, I distinguished between two levels of experience:  There is a way of experiencing which is not the output of processing information about the world, but consists in the very processing of that information.

Here's a simple task which, though not conclusive, is suggestive.  Focus on something specific, such as the computer screen in front of you.  Now, close your eyes for a moment, and quickly open them again so that you are looking at the same object.  It will take you a moment to readjust your focus.  Why is that?  Why can't the brain just pick up right where it left off?  I think the reason is that our visual experience is complex, and it requires some regulatory feedback between the various parts of our neural system.  The eyes are part of that process.  The eyes have to latch on to an object, and our full visual perception cannot occur without that lower level perception.  If perception did not occur until after the eyes grasped an object, then why would we experience the process of focusing the eyes?  Part of what happens when we focus on an object is a synchronization between the eyes and higher-level neurological funcions.  The fact that we experience this synchronization suggests to me that what happens in the eyes is a part of our experience, and not merely a pre-experiential component of our information processing.  The lower level perception actually constitutes some aspect of the higher-level perception.

Of course, as you note, if all we had were eyes, we would not experience anything.  But this is no objection to my point.  I do not claim that eyes alone are sufficient for experience, just as I would not claim that the heart alone is sufficient for the pumping of blood.  But the heart does pump blood.

In sum, experience begins when information is presented, and this occurs as the eyes interact with light.  Thus, experience begins immediately upon our interaction with the world, and not at some later time.  We can thus reject your first premise.

If I am correct, then what can we conclude?  Perhaps we should be more sympathetic to the view that experience is not an object or state, but is rather an interactive process which occurs between ourselves and the world.  This may be why facts about experiences are not clearly facts about objects or properties of the world, and not clearly facts about dispositions or capacities, either.  See for example Ryle (1949, Chapter 7).  Perhaps this is something like what Anne Jacobson means when she says we should avoid the idea of perception as looking at a picture (or a film, I would add).

Regards,
Jason
April 21, 2010

2010-04-25
The time-lag argument for the representational theory of perception
Reply to Anne Jacobson
Hi Anne

Thanks for your comments.

I'm personally more interested here in what people think of the argument at the start of the thread, rather than in the representational theory of perception. That is, can you identify any steps in it which you think are problematic?

You seem to at least partially question step 1 - if so, please let me know what you think of my comments in my above post: http://philpapers.org/post/3583

Best wishes

Derrick

2010-04-25
The time-lag argument for the representational theory of perception
Hi everyone

I've come-up with a third version of the argument:

1) Your vision lags behind the scene in front of you by at least the roughly 0.1 seconds it takes visual information to travel from your eyes to the visual areas of your brain and then be processed.

2) Therefore, someone walking in front of you at a relatively slow pace of one metre per second will have actually travelled about a further tenth of a metre from where you perceive them to be at any moment.

3) If there is a difference, at any particular point in time, between what you are directly experiencing, visually, and the scene in front of your eyes, then they cannot be literally the same thing.

4) Therefore, what you directly experience, visually, when you look at the world cannot be the world itself, and must instead be merely a mental representation of it, generated by your brain from the information that it receives from your eyes.

Please let me know what you think.

Derrick

2010-04-28
The time-lag argument for the representational theory of perception
Derrick, I think the third step of your new version of your argument is still a mis-step. You contrast what we get in vision, "a mere mental representation of the world," with the world itself, and what you take to make it so mere, and so representational, is the small time lag. I think you need to ask if any state of mind is non-representational, in your sense (which is not mine, where a representation must be a repeat presenting) and why you regard such things as "mere." Vision too is part of the world, as are our mental states. What you get in vision is not old news, but as breaking as we get, and it is not a representation in the sense that your memory of what you saw this time yesterday would be--typically sketchy, with the details missing. What you get in vision is what Hume called an impression, quite different from the idea copies of it we get in "mere" thought and memory. Its as direct and up to date as we get, so, if you cannot contrast it with anything better, why call it "mere?" Merely asking, Annette B  

2010-04-28
The time-lag argument for the representational theory of perception

I have a lot of sympathy for Derrick's rephrased position (more or less the standard scientific one), with the caveat that 'experience' and 'representation' are difficult polysemic words. As transitive verb 'experience' probably has to have two forms. 'To experience the world' probably means 'get information about what is really going on outside' and has to be via many steps, but not via a 'proxy' of outside actuality, since there is none. (There is no 'replication of objects'.) 'To experience content' is a useful alternative form for philosophers of mind but needs to be treated as a different verb. The problems of representation have been covered.

Jason Streitfeld raises some interesting points. Firstly: 'Perhaps we should be more sympathetic to the view that experience is not an object or state, but is rather an interactive process which occurs between ourselves and the world.'

This, again, is the standard scientific position. The difficulty comes, as Jason indicates, when we want to identify the interface between self and world. There is often a tacit assumption that a brain is all 'self' in this context. However the physical dynamic interactions in brains are, as far as we know, exactly the same as those outside. We have no justification for ascribing some new 'experience-generating' property to all the interactions within brains but not to the linked interactions a bit, or much, further out in the world (superior colliculus, optic nerve, retina, cornea, tear film, contact lenses, cochlear, tympanum, room air, or wherever). Nothing relates the interactions within brains together in a way that does not relate them with outside interactions. So if we want to relate experience to an interaction, as we do, we have to say which one. We cannot pick an aggregate. There is no 'brain's interaction with the world' that includes multiple 'processes' within the brain (the two would seem mutually exclusive anyway).

'There is a temptation to say that experience occurs some time after the brain has done some work.'

This is not so much a temptation as experimentally demonstrated fact. Masking studies show you can block reportable experience after the retina has received signals. Nevertheless, I would agree with:

'The question then is whether or not this first level of [retinal] interaction constitutes some level of experience.  This is not an easy question.'

There may well be experiences involved in retinal interaction - millions of them - but not of the sort owned by the sorts of experiencing entities in brains that are also aware of being involved in philosophical debate. Nor would I want to suggest that such experiences relate to 'capturing or presenting images'. I am not sure what that could mean.

I am afraid that I do not think the thought experiment offered on focusing on a screen justifies rewriting several decades of work in physiology labs, which point to the conclusion that all features of visual percepts relate to events occurring after activation of visual cortex V1 area. There are multiple routes from there on that carry both 'low-level' perceptual and higher level conceptual information and quite a lot is known about how these routes relate and how they can be tricked into conflicting. We experience the process of focusing because the cortex initially gets poorly collated low-level data and only subsequently gets the benefit of better collation and higher level interpretation after ciliary body and temporoparietal cortical feedback have kicked in.

Jason concludes: '…experience begins when information is presented, and this occurs as the eyes interact with light.  Thus, experience begins immediately upon our interaction with the world, and not at some later time.  We can thus reject your first premise.'

If this relates to the experience of entities that are also aware of philosophical arguments then we have clear experimental evidence that it is not the case. Nevertheless, if some site of interaction deeper inside the brain is associated with an experience of both a screen and a philosophical argument then it is hard to deny the possibility that other interactions may also be associated with some sort of experience. Since the brain supports vast numbers of interactions that transmit the sort of information we would expect to encode experience we should, by default, assume that there will be vast numbers of experiences. All of these will be in keeping with our perceptions at the time (and contribute to reporting) but the evidence available indicates that multimodal experience (sound, vision, emotion, reason) can only be supported by interactions at the front of the brain because of the connection architecture. There should still be vast numbers of those. (As I indicated, we have no legitimacy for lumping interactions together.)

This conclusion surprises, confuses and upsets a lot of people but it is as far as I can see the only one that fits with natural philosophy rather than supernatural animism. No one experience need be more important nor more 'truly me' than another - which is perhaps the only significant missing argument in Leibniz's otherwise very reasonable account.


2010-04-30
The time-lag argument for the representational theory of perception

This post contains replies to several people:

------------------------

Hi Luke:

You wrote:
We also seem to disagree over whether the content of those present perceptions is of the past or of the present. You say they are of the past, while I say they are of the present.
Sorry, I might have missed this, but why do you believe that the content of your perceptions in the present is the world of the present if the content of your perceptions in the present is the world as it was at the beginning of the time-consuming perceptual process?
If the content of what we perceive in the present is the "world of the past", then does this mean that we can never have (direct) perceptions of the "world of the present"
That's what I believe.
 - that the present is forever out of our perceptual grasp?
I would say that we can perceive the world of the present, but only indirectly, via a mental representation, and after the fraction of a second it takes to create that representation.
But wasn't the present the time at which we are having perceptions, anyway? Instead of the present minus the lag time?
The content of our perceptions in the present exists in the present (obviously), but that content is actually the world of a fraction of a second in the past.

-------------------------

Hi Jason

You wrote:
In other words, the time-lag does not necessarily create a disparity between the here and now and the content of the experience of the here and now, even if experience is a presentation of that reality.
I think there is always be a very significance difference between the world and the content of our perceptions at the same point in time: whereas the former is the world of the present, the latter is world of the past. This applies even you are literally watching paint dry.
The time-lag would only be significant for those events which occur at relatively high speeds.
But even you do concentrate on differences of detail between the world and the content of our perceptions, even insignificant differences are still differences, and if the content of our perceptions literally is the world, then there cannot be any difference at all between the two at the same point in time. Also, there exist significant differences even at low speeds - such as the example I gave of a person walking at a relatively slow pace of 1m/s having travelled a further tenth of a metre from where we perceive them to be.
The question then is whether or not this first level of interaction constitutes some level of experience.  This is not an easy question, but it appears that the eye does have some functional characteristics which are capable of constituting some level of experience. ... The point is only that the eye is capable of capturing or presenting images, and this can constitute one level of perceptual experience.
But as I said above:

"This raises two questions:

1) Which specific aspects of our visual experience are caused simply by light striking the retina?
2) What is the mechanism for this event having an effect on our vision, given that at that point the information contained within the light has not reached the brain, never mind been processed?

While we certainly wouldn't see at all if we didn't have eyes, so we equally wouldn't see at all if we had eyes but no brain. Therefore, the brain has to have a part in every aspect of our visual experience, whereas the above objection implies that there would at least some form of visual experience if your brain was removed but light was falling on your retinas."

Re your experiment:
Why can't the brain just pick up right where it left off?
Because the brain quite rightly doesn't assume that the scene in front of our eyes has not changed while our eyelids were closed.
If perception did not occur until after the eyes grasped an object, then why would we experience the process of focusing the eyes?
Because it's only the eyes and the brain together which 'grasps' an object: the eyelids open, and the retinal image is blurred, which results, 0.1s later, in a blurred mental image, and the brain then sends instructions to the eyes which ultimately bring the retinal image into focus, which then leads to a mental image that is in focus.
I do not claim that eyes alone are sufficient for experience
But if the brain is necessary, then how can light striking the retina contribute immediately to visual experience?
In sum, experience begins when information is presented, and this occurs as the eyes interact with light.
But what is the actual mechanism for light striking the retina contributing immediately to visual experience? For example, why does an image being projected onto the retina contribute immediately to visual experience when an image projected onto your left cheek with a glass lens would not at all?

And which specific aspects of visual experience are, and are not, caused immediately by light striking the retina?

----------------------------------

Hi Annette

You wrote:
I think the third step of your new version of your argument is still a mis-step. You contrast what we get in vision, "a mere mental representation of the world," with the world itself, and what you take to make it so mere, and so representational, is the small time lag.
The third step in my most recent argument version of the argument doesn't refer to mental representations. It also doesn't refer to the time lag, but to the implication of the difference, at the same point in time, between the content of your vision and the scene in front of you (which happens to be caused by the time-lag, but that is not relevant at this particular point in the argument - the logic of step 3 would be applicable regardless of the reason for the difference). Step 3 is making the point that, given that difference at the same point in time, they can't be literally the same thing.

Re representation as re-presentation(!), I'd be interested in what you think of my reply above about this point, in which I said: 'I think that the proposed mental representation is indeed a re-presentation - it's a mental re-presentation of what was physically presented to the eyeballs 0.1s earlier. The information that a digital camera receives is received by the camera 'for the first time', but the image on the screen on the back of the camera is still a re-presentation - it's a re-presentation of the information presented to the lens of the camera a fraction of a second earlier.'

Your point here seems to be that, if vision is indeed a mental image, then the term 'representation' is inappropriate. But if vision is a mental image of the world, and not the world itself, then I don't see how it can be anything other than a representation of the world, just as a photograph is a representation of the world.

Re 'mere', I think this term is appropriate: Our impression is that vision is a direct experience of the world, and so if it is actually a mental representation of the world, and not the world itself, then it is legitimate to refer to that representation as a 'mere' representation, as opposed to the real thing - just as we refer to a 'mere' mirage.
What you get in vision is not old news
It's the world of 0.1 seconds ago, and that delay means that a car travelling at only 22mph will have travelled a further metre from where we perceive it to be.
Its as direct and up to date as we get, so, if you cannot contrast it with anything better, why call it "mere?"
You're right, but the problem for the 'common sense' theory of direct perception is that 'up to date as we get' is a delay of 0.1s in the case of vision. And that delay means that there is a difference, at the same moment in time, of 1 metre between where the car is located in reality and where it is located in our vision. And that difference, at the same moment in time, means that what we directly experience visually cannot literally be the same thing as the scene in front of our eyes. And that means that what we directly experience visually must be merely a mental image/representation of that scene. And such a mental image/representation can be contrasted with what we think we are directly experiencing, the scene itself - hence, 'mere'.

2010-05-02
The time-lag argument for the representational theory of perception
Hi Derrick,

"Sorry, I might have missed this, but why do you believe that the content of your perceptions in the present is the world of the present if the content of your perceptions in the present is the world as it was at the beginning of the time-consuming perceptual process?
"

Perhaps I'm just restating the naive realist position that you're arguing against, but I believe that we use "the present", in most cases, to denote both the time at which we are conscious, and the content of our conscious perceptions at that time. You wish to argue for a more objective perspective - to take into account the logic that there must be a time lag in visual processing between light hitting our eyes and our perceptions of that image, which explains why our perceptions lag behind the world (of the present) by a fraction. But do they? To accept this, I also have to agree that the "true" present moment - when the "world of the present" resides - is a (pre-lag) time prior to perception, at which we are unaware of the world - when light first hits our eyes. If this is the present moment then we can never be conscious of this "world of the present".

But then there is a second present moment to consider, which comes after the time at which light has hit our eyes, and after the brain processing lag. This is the post-lag present moment at which we have become conscious of the image contained in the light which hit our eyes.

But these can't both be the present moment.

Your argument is that we cannot become conscious - like we do at the post-lag present moment - of the world as it is at the pre-lag present moment. My argument is that the pre-lag present moment is not the present moment at all, and that the post-lag present moment is our usual referent of "the present". The content of our perceptions in the present moment are just what we call the present moment, or the world of the present. Instead of the second, more objective, pre-lag present moment which you've created 0.1 seconds earlier than it.    

"I would say that we can perceive the world of the present, but only indirectly, via a mental representation, and after the fraction of a second it takes to create that representation."

So, I ask again, is there such a thing as a direct perception? What form of perception would a direct perception take, since it cannot be merely an indirect mental representation?

"The content of our perceptions in the present exists in the present (obviously), but that content is actually the world of a fraction of a second in the past."

I would say that the "world of a fraction of a second in the past" looks just like the world did a fraction of a second ago.

2010-05-06
The time-lag argument for the representational theory of perception
This post contains responses to both Jonathan C.W. Edwards and Derrick Farnell.

Jonathan,

You take issue with my claim that experience can begin as the eyes first respond to light, observing that "studies show you can block reportable experience after the retina has received signals."

I accept that reportability requires significant cognitive processing.  However, we can distinguish between reportable experience and experience simpliciter.  So I do not think you have successfully countered my point.

Both you and Derrick object to my experiment about focusing. As I said, I do not think the experiment is conclusive, though I still think it is suggestive.  Consider your explanation (which, I think, is basically the same as Derrick's).  You say,  "We experience the process of focusing because the cortex initially gets poorly collated low-level data and only subsequently gets the benefit of better collation and higher level interpretation after ciliary body and temporoparietal cortical feedback have kicked in."

According to this view, we experience the initial act of focusing the eyes because the eyes capture blurred images and this information gets sent to the visual cortex.  We see clear images only later, after better images are received and feedback between various parts of the brain begins.  Thus, the experience of the blurred images cannot rely on temporoparietal cortical feedback.  It must occur by the simple fact of blurred images being received by the visual cortex.  But then why stipulate that the images must be transmitted to the visual cortex before they are experienced?  There doesn't seem to be any work for the cortex to do, so why can't the capturing of the image itself constitute some level of experience?

---------

Derrick,

1.  You say there is "a very significance [sic]  difference between the world and the content of our perceptions at the same point in time: whereas the former is the world of the present, the latter is world of the past. This applies even you are literally watching paint dry."

I understand that this is your position, though I do not think it follows from the fact of a time lag between an event and our experience of it.  Consider, first, a point I made in my first post in this discussion:  Events we see with our eyes occur before light strikes our eyes.  So, for me to see event X, there must be a lag between the beginning of event X and the moment my eyes receive information about event X.  So visual perception is always of events that occurred in the past.  However, this does not mean that the content of our perception is significantly different from what it is about at the same point in time.  We agree there is a difference--we just disagree about whether or not the difference is necessarily significant.

Consider this argument.  Some facts about X need not entail every fact about X. In other words, we can image Y which is in some way physically distinct from X, such that there are facts which are true of both X and Y.  (Clearly there are facts about X which are not true of Y, and vice versa.  This doesn't matter.)  Now, say we get information about X at t=1.  The information originated from X at t=0.  X has changed in the interrum, so that X no longer exists at t=1; X has become Y.  Is there a significant difference between X and Y?  Not necessarily.  All of the relevant facts about Y may be true of X, and vice versa.  (Here "relevant facts" may just be facts that we are capable of reporting.)

2.  In response to my rejection of your first premise, you ask: 

"1) Which specific aspects of our visual experience are caused simply by light striking the retina?
2) What is the mechanism for this event having an effect on our vision, given that at that point the information contained within the light has not reached the brain, never mind been processed?"

The second question presupposes that the functionality of the eye is not a part of the functionality of the brain, and that some processing must occur before any sort of experience can occur.  I don't think these are fair presuppositions, so I won't bother trying to answer the second question.

I am not sure that I should feel pressed to answer your first question, either. 

First, my view is not that some level of experience is caused "simply by light striking the retina."  Rather, it is that some level of experience is constituted by the direct response to light.  It is not enough to have light strike the retina, because the retina must be a part of a system functionally capable of responding to light in a certain way.  So light striking a detached retina would not produce an experience.

Also, you suggest that the eye itself is no more capable of constituting experience than the left or right cheek.  Yet, the eye is demonstrably capable of complex behaviors which do bear a resemblance to processes associated with visual imaging.  So let me turn your question around:  What is the difference between information contained in light which strikes the eyes and information contained in the output of neurological processing?  If experience is output, as you say, then experience is just information.  So how do you distinguish this particular type of information as such?  What makes some information experience, and other information not experience?

I think it makes more sense to regard experience as a process, and not as output or information.  Once that step is made, the question is:  what sorts of processes constitute experience?  And I say, why discount the processes that occur when the eyes respond to light?

I do not claim to have a clear account of any level of perception.  However, I think my view is at least plausible.  It is plausible that experience is complex, and that there are levels or aspects of experience which we cannot (presently) distinguish as such.  I think this view is rather similar to, or at least compatible with, Dennett's "Multiple Drafts" view of consciousness (Dennett, 1991).

Regards,
Jason
May 2, 2010

2010-05-06
The time-lag argument for the representational theory of perception
Luke, and anyone else

I've re-worded the version of the argument at the start of this thread so that it no longer refers to the present:

1) Your vision is dependent on visual information about the world reaching the visual areas of your brain, via your eyes, and then being processed, all of which takes a period of time, t.

2) Therefore, the content of your vision at any particular point in time, T, is actually the world of T-t.

3) However, the world of T-t cannot, by definition, itself exist at T - only the world of T can exist at T - although a representation of the world of T-t can exist at T.

4) Therefore, what you directly experience, visually, when you look at the world cannot be the world itself, and must instead be merely a mental representation of it, generated by your brain from the information that it receives from your eyes.

Derrick

2010-05-06
The time-lag argument for the representational theory of perception
Hi Derrick,

In your most recent formulation -- http://philpapers.org/post/3691 -- your first premise mentions 1/10 second as a rough minimal calculation from the time the light is at the EYES until some point at which an associated conscious experience is happening.  So, at best, your premises support the conclusion that it's impossible for there to be a direct perception of something external to the head, beyond the eyes.  

So, you overstate your case when you say that your premises imply that it is impossible to perceive the world directly.  For your premises are consistent with the possibility of perceiving at least some of what is in the head directly, which is what Bertrand Russell, for the last 50 or so years of his life, took to be the proper lesson of the time-lag argument.

Cheers, 

James Grindeland

2010-05-06
The time-lag argument for the representational theory of perception



1) One's vision is dependent on visual information travelling from one's eyes to the visual areas of one's brain, and then being processed, all of which does not happen instantaneously, but takes a finite amount of time, however small.

Hello fellow members,

Vision and visual information does not exist - what exists is the optically equipped and visually informed embrained observer and the photonic particles (datergy) which impact the observer's retinas after bouncing off the surface of (say) the apple, which when converted travels to the visual cortex and informs the brain of that which its exterior sensorial receptors (the eyes) have scanned.

Every object in the cosmos changes - if it did not - it would not exist in the first place. In the brief eventitive interstice betwixt the photonic bombardment of the eyes and the receipt of the visual datergy by the central nervous system the apple and the observer undergo certain changes. Both the apple and the observer have very slightly changed in the intervening period of delay. Even if the transfer was instantaneous the apple and the observer would not be EXACTLY the same objects as before for quantum change is continuous.

The delay is over so quickly that it would not even allow you time to blink. If you however you look at any object around you then blink, the object appears exactly the same as before you blinked. However, if somebody suddenly turned off the light at the same moment you blinked - when you reopened you eyes you would not be able to see the apple. Does that mean that the apple exists in a different existential modality? Yes, and it means that you do too - for you cannot see in the dark. It is possible that the apple has remained less changed, for  its rate of decomposition will have slowed slightly because of the absence of ultra-violet rays. But *nature* is unconcerned (sorry about the personification) with such tiny delays.

The complicated neuro-physiological variables of evolutionary survival involve concessionary modification of organic structure. In a successful species the centre of the neural-structure is physiologically located in what evolutionary elimination (sorry about the reification)  has deemed to be the safest structural position. In human animals, for structural reasons connected with its upright bipedal anatomy the command-centres of the body-wide neural-system are located at the top of the body within the skull out of harms way where it is protected from the potentially injurious environment within a thin bony brain-case. In other words after millions of years of trial and error *nature* is satisfied that the optical nerve length is adequate for the successful continuation of the species. In other words as far as *nature* (sic) is concerned the eye-brain configuration is the best possible and the length of the optic nerve is in accordance with optimum survival.

2) Therefore, the content of one's vision in the present is always the world of the past, however recent.

The *past* it is a reificative convenience that does not exist - it is no more than a useful fiction. That which once was Caesar  has now changed its existentially modality and still exists - though in changed forms, (some of which  could be in that coffee you are drinking.)  ;-)

3) The past, however recent, cannot itself exist in the present, by definition, although a representation of it can.

Ontologically Representations of antecedal visual events  do not exist. What exists is the presenting brain - what we see is only presentable to the neurologically equipped presenter.  What exist are contemporay objects (which we reify as such) which remind us of what was once observed prior to change.  Visual brain content does not exist - only that which is contained and its container exist. (i.e. the skull and the thinking meat therein)  Only the regarder and that which is regarded exists. When gazing at a *representation* one is not regarding the *past* one is regarding that which is present.

A picture, a sound, a model of  *the past* is not a representation of *the past* it is a currently existing configuration of dried paint particles or electrons on a PC screen or  some other material medium,  which is intelligible only when it is regarded by the an embrained human  - it is not the *past* he sees, but an image that reminds him of certain objects before he and they changed the existential modality.

4) Therefore, what one directly experiences, visually, when one looks at the world cannot be the world itself, and must instead be merely a mental simulation of it, generated by one's brain from the information that it receives from one's eyes.

If one looks at a brick wall - closes one's eyes - then opens them again - then bangs one's head hard on the brickwork, one will soon discover that it does not exist as a mere mental simulation, generated by one's brain from the information that it received from one's eyes before they were closed. This is *nature's* way of dealing with the situation.

Any doubts are easily expunged by using the head,  which is also a useful sensor, specially when used as a battering-ram (Dr. Jonson preferred to kick a stone or recommend his companion to do so) and although there might be another small delay before an egg-like lump appears,  one can be certain that both the headbanger and the wall exist.  :-) This is why nature is content with the current deterministic catenulate design node as far as the human sensor is concerned and the small delay is not a survival threat to our species.

Best wishes,

Jud Evans
Athenaeum Library of Philosophy.

http://evans-experientialism.freewebspace.com/study.htm


2010-05-06
The time-lag argument for the representational theory of perception
Reply to Luke Culpitt
Hi Luke

I think we're talking past each other, because we have different definitions of the present. You're defining the present in terms of the one's consciousness ('I believe that we use "the present", in most cases, to denote both the time at which we are conscious, and the content of our conscious perceptions at that time'), whereas I would define the present moment as simply the point in time which separates the future and the past.

Derrick

2010-05-10
The time-lag argument for the representational theory of perception
Hi Jason

I'm afraid that I'm not clear about your position.

For example, you state in an earlier post that
... experience begins the moment light interacts with the eyes.  We should therefore reject your first premise.
but you also state in your last post that:
my view is not that some level of experience is caused "simply by light striking the retina."
It would perhaps help if you could respond to the following specific point:

If your optic nerves were severed, or the visual areas of your brain were removed, then you would not have any visual experience at all. This leads to the conclusion that the processing in the brain, of the visual information received from the eyes, is a necessary component of the visual process. This in turn leads to the conclusion that light striking the retina only results in a visual experience once the visual information contained within that light has travelled from your eyes to your brain, and then being processed there, all of which takes time.

Derrick







2010-05-10
The time-lag argument for the representational theory of perception
Hi James

You wrote:
your premises are consistent with the possibility of perceiving at least some of what is in the head directly,
But perception is an experience - direct or indirect - of what is at the very start of the perceptual process. That is, we can only visually experience - directly or indirectly - those aspects of the world which impinge on our eyes, and the only thing impinging on our eyes is the light from the scene in front of us.

And even if visual perception were a direct experience of something physical inside one's head, that perception would still require a time-consuming processing of information, and so the same logic would still apply.

Derrick

2010-05-10
The time-lag argument for the representational theory of perception

Dear Jason,

When I talk of reportable experience I simply mean experience that is of the sort that can be reported, discussed or referred to, in the sense that your 'experience simpliciter', is patently discussable. The 'cognitive processes' of any subsequent reporting are irrelevant to an account of the experience.

I am glad that you admit that your thought experiment does not distinguish between explanations. You continue to talk as if 'images' are something that can be 'captured' or sent from one place to another.  We are dealing with an account of the dynamics of the world and the sort of rigorous account of dynamics that scientists use, and one would hope philosophers would be even more rigorous about, does not include this sort of folk concept. What is a 'sendable image' in your account?

Signals must be transmitted to the visual cortex before they are experienced as blurred for a very simple reason. A sense of blurring is based on the relation between signals encoding brightness in various parts of the visual field. Nothing in the retina has access to the relations throughout the visual field. The signals received in all the areas of my right retina are not linked up within the retina any more than they are with areas in your right retina. To get blurring, signals have to be brought together so that they can have a causal relation. That is what brains are for. This is trivially basic dynamics. (In a sense you answer your own question in the point about a detached retina!)

I realize that this basic analysis causes discomfort for many. Appeal to magical things like 'images' is apparently rife not only amongst philosophers, but also neuroscientists. Often there are also appeals to arbitrary 'functional systems' (as in your reply to Derrick), again magical constructs, that, to do any explanatory work, require invocation of retrograde causation (see my thread on the impossibility of functionalism). But if a problem gets difficult the answer is not an animistic Deus ex Machina, it is sticking to careful, if painful, argument.

The problem is not that Derrick is wrong. He is merely stating the first premise of a usable theory of experience. The problem comes with pinning down exactly which interaction is associated with an experience of the sort we are discussing. To resolve that is hard but to do it I think we need to clear our heads of all folk-ontological concepts like 'image', 'system', 'simulation' and probably 'representation' and 'presentation', not just once but time and time again. We need to get back to using dynamic accounts the way the great philosopher scientists like Newton and Leibniz intended them to be used, not all muddled up with the experiences they are intended to explain. Sadly that muddling is embedded in schoolroom teaching, but surely the whole point of philosophy is to unmuddle such schoolroom muddlings?


2010-05-24
The time-lag argument for the representational theory of perception
Dear Derrick, All power to your elbow on the basic premise. I take issue with your reply to James only to try and clarify why I think there are further layers.
You say that perception is an experience of what is at the very start of the perceptual process. You then seem to contradict that by saying that we can only experience what impinges on our eyes - which is surely not at the start of the process: 'the start' would seem to be the scene itself. I do realise that you are addressing a different point from James (which I think just is just at cross purpose to you) but the problem of the whole idea of 'an experience of a scene' has to do with the idea that there is any sort of 'start'. Take an 'experience of a rainbow'. Where does that start? We might say 'OK there is no structure that is a rainbow but at least there is a band of blue above bands of green and red that we can experience'. But the very aboveness of the blue is an artefact of the positions of sun, rain and me. There is no blue rain or red rain. If we experiencing anything it is probably the sun, or maybe the Big Bang. If we look at a face in a mirror are we experiencing the face or the reflection? If we hear Nellie Melba on the car radio are we experiencing Nellie, the CD, the wobbling of the speaker diaphragm, the electric perturbations that move the diaphragm, the air that hits our ears, or what. 'Experience of' contains a category error we need to work around. There is a  long sequence spreading back not only in the neurology but in the world beyond the head and there is no boundary relating to arbitrary 'systems' or 'objects' in the dynamics. The 'start' is something we impose in our defining of the 'object', as portrayed in experience, which is, in dynamic terms, ontologically empty.

The problem takes a slightly different form in the context of 'experiencing something physical inside one's head' where experiencing is a different verb, with a different metaphysical category of object - not the object conceived by the subject but by a third party and I wonder if 'the same logic applies'. If the experience (in this new sense) is of the input to a single interaction, then maybe it really is 'current', especially since in modern physics a single interaction occurs in a finite (i.e. extended) domain of time but cannot be broken down into separate points in time within this domain. That does not mean that it cannot be an experience of  (in the first sense) a decade encoded in 10 milliseconds but there may be no 'waiting for the kettle to boil'.

2010-05-24
The time-lag argument for the representational theory of perception
Responses to both Derrick and Jonathan follow.

Derrick,

You say, "If your optic nerves were severed, or the visual areas of your brain were removed, then you would not have any visual experience at all."

I agree.  You wouldn't have any visual experience.  Whether or not something occurring in the eye could be classified as "a visual experience" is another matter.  It depends on what we count as "a visual experience" and what would happen in an eye that was disconnected from the rest of the brain.


Jonathan,

You say, "When I talk of reportable experience I simply mean experience that is of the sort that can be reported, discussed or referred to, in the sense that your 'experience simpliciter', is patently discussable."

I agree that experience simpliciter is discussable, in theory.  But I think there are aspects, levels, or elements of experience which are, practically speaking, unreportable.  We may learn to access these elements in the future, and we may learn how to discuss them in neuroscientific terms--so the unreportability here is not necessary, but only contingent.

I will give you an example to illustrate what I mean.  This is something that I just came across, and I find it very interesting. If you go to this link, you can see an optical illusion published by Scientific American.  It shows a checkered board with squares alternating between light and dark shades of gray.  The illusion is that two of the squares (marked A and B) look like they are quite different shades, when in fact they are identical.  They are the same color and brightness.  The note attached to the picture says, "Our brain does not perceive the true brightness and color of each square . . ."  Yet, if you are good at manipulating your eyes, you can focus only on squares A and B, so that the rest of the picture fades into the background.  When only squares A and B are in focus, it is clear that they are the same shade and brightness.  (I am not sure why, but some people find it impossible to manipulate their focus in this way.  I guess I'm lucky.  I happened upon this "solution" to the illusion without much effort at all.)

Contrary to what Scientific American says, the brain does perceive the true brightness and color of each square.  Yet, that aspect of our experience is not reportable . . . or, at least, it takes some effort to adjust our vision to make it reportable -- and for some people, this adjustment may not even be possible.  Our reportable experience is what we are capable of saying truthfully about what we experience. But we can still have experiences (or aspects, levels, or elements of experiences) which we cannot report, or which we have a very strong tendency to report incorrectly.  It also seems plausible that there could be aspects of our experiences which we do not even know how to recognize as such--aspects which are not known in the way that color and brightness are known to us--and which we could therefore not even begin to think about reporting.

As for blurred vision, I will concede that point for now.  It is not crucial for any of my arguments.

You say, "The problem is not that Derrick is wrong. He is merely stating the first premise of a usable theory of experience."

Then perhaps you can answer the question I addressed to Derrick:  If experience is information (as would be the case if, as Derrick says, experience is output), then how do we distinguish between information which is experience and information which is not experience?  Perhaps you (and Derrick) want to argue for the existence of phenomenal information, though that notion carries some baggage associated with epiphenomenalism.

By the way, I don't see any reason to worry about terms like "image" when discussing the functionality of the eyes--I am under the impression that it is standard to talk about retinal images in all sorts of scientific contexts; nor do I find any problem with the terms "system" or "function" here.  (I do recall a PhilPapers discussion in which functionalism was criticized, and I recall observing that the variety of functionalism which is perhaps most alive today did not seem to be implicated.)

Regards,
Jason
May 15, 2010

2010-05-27
The time-lag argument for the representational theory of perception
To Derrick and Jonathan:

Jonathan says the perceptual process begins not at the perceiver's eyes (or other sense organ) but at the scene which the eyes see. But of course without seeing eyes there would be no vision, so the start is the combination of seeing eyes and scene viewed. And if that scene is of stars, the light may have taken a very long time to reach the eyes, so the time lag is especially impressive for seeing stars. Does this mean that the seen stars are mere representations of their long-ago source? Only, it seems to me, if there is any more direct way of accessing what is seen. The theory of representative perception, which gives its name to this thread, contrasts with the view which claims we can have direct perception, but if seeing is as direct as we get, more direct than say memory or seeing something reflected in a mirror, then even if there is time lag, sense perception is our directest access to what is there. That it is mediated by retinal images and brain processing does not mean that the end product is a representation, unless we use that term for any and every thing before a mind. Hannah Pitkin wrote a fine book on representation, where the political sense was taken as primary. We contrast direct democracy with representative democracy, and under the latter, an elected member of parliament represents her constituents, and can do so well or badly. What does our visual field represent? Derrick thinks it represents our surroundings as they were was at least .1 of a second ago, an interval which does not exceed that included in the specious present, the smallest junk of time we can discriminate in consciousness. But this can as aptly be said to be presented, not represented. Otherwise really indirect knowledge, say by hearsay or by memory, has to count as a representation of a representation. There are such things (photos of copies of paintings) but something has to count as the original, if its derivative version is to be a representation. So, interesting as the time lag in perception is, I do not see it as a reason to call sense perceptions representations, unless all you mean is Kant's "Vorstellungen," which are better translated as what stands or is before the mind. The earlier holders of a view of representative perception held that view because they thought that perception misrepresented what is out there, matter which lacked color, etc. Derrick too thinks we misrepresent what we perceive if we take it to be the current, rather than the just past, state of our environment. But now he has put us right about that, we can from now on avoid the error, and take sense perception, at least take vision, to inform us about the just past state of our world. It will still present that state, and present it as just past. Then our memory, and later reports to others of what we saw, will be genuine representation, repeat presentations. But I repeat myself, again.  

Annette Baier    

2010-05-27
The time-lag argument for the representational theory of perception
Hi Jo

You're right in your criticism of my reply to James - I should have said:
... we can only visually experience - directly or indirectly - those aspects of the world which impinge on our eyes, and the only thing impinging on our eyes is the scene in front of us, via the light coming from it.
I understand what you say about identifying the start of the perceptual process, but I still think that it is possible to do this. The start of the perceptual process is the point in space and time that is impinging on our sense organs, whether immediately - in the case of touch - or via light, in the case of vision. (Of course, even in the case of 'immediate' interaction, the sensory information needs to reach the brain and be processed.)

For example, when we see an oak tree we do indeed visually experience an oak tree, at a specific point in space and time, and not, for example, the acorn from which it grew.

In the case of seeing a rainbow, I would say (as perhaps you would too) that a rainbow is simply an optical illusion, similar to one's experience of water apparently lying on a hot road in the distance. Therefore, in the case of seeing a rainbow, I wouldn't say that the rainbow is the start of the visual process, because the rainbow doesn't exist at a point in space. However, I would still say that the start of the perceptual process is the point in space and time where the sunlight is interacting with the rain.

In the case of looking at a face in a mirror, I would say that the start of the visual process is the reflective surface of the mirror. That is, one's experience of the face is, in my view, doubly indirect: first, it's a reflection of the face, and what we experience is only a mental representation of that reflection.

In the case of hearing a singer on the radio, I would say that they start of the perceptual process is sound waves emanating from the speakers. Just as the acorn isn't the start of the perceptual process when we look at the oak tree, so the singer isn't the start of the perceptual process when we hear a recording of their voice.

Best

Derrick

2010-05-27
The time-lag argument for the representational theory of perception
Hi Jason

You say that you agree that I wouldn't have any visual experience if my optic nerves were severed, and so you must therefore agree that my visual experience is dependent on visual information reaching the brain and then being processed, which undeniably takes time - which is what the first premise is stating.

Best

Derrick

2010-05-29
The time-lag argument for the representational theory of perception
Derrick,

You say:  "You say that you agree that I wouldn't have any visual experience if my optic nerves were severed, and so you must therefore agree that my visual experience is dependent on visual information reaching the brain and then being processed . . ."

I don't see why I must agree to that.  Though, to clarify, what I agree with is that, for you to have a visual experience of the world, your optic nerves cannot be severed.  We might suppose that something we might call a "visual experience" could be possible even for people who cannot see, and whose optic nerves are severed.  Though I suspect such visual experiences are quite unlike the visual experiences we have of the world, and we would hurt the discussion if we failed to distinguish between these varieties of visual experience.  I never said that visual experience occurs only in the eyes.  I never said some aspects or levels of visual experience do not occur after some degree of neural processing. The point is that you have not shown that some variety of experience does not occur in the eyes, when the eyes directly interact with the world.  So we have reason to be suspicious of your first point.

Regards,
Jason
May 27, 2010




2010-05-29
The time-lag argument for the representational theory of perception
Trouble is, Derrick, that your choices of 'starts' for perceptions are arbitrary and based on folk physics (not even some 'physics-free' a priori rationale) rather than anything consistent. 
Let's look at the rainbow. I do not think this is an illusion in the sense that it seems to be something it is not. Is the blueness of sky an illusion? If you follow this further you find everything is an illusion in some sense - and this relates to the basic point that nothing exists at a point in space in the way that you would like it to so that experience can simulate it. That is not how physics works. Moreover, there is a problem with the perception process for the rainbow starting at such a point because there is none. The phenomenon relates to refraction of light many times as it passes through a mile or so of rain. The pattern produced is a statistical phenomenon. Where does the perception of a red setting sun start if the redness is the effect of diffraction across a hundred miles of atmosphere. Does it start at the sun or the atmosphere or where. There is no sensible answer.

Why does perception start at the mirror for the reflection. Reflection and refraction are fairly similar in basic physics. That ought to mean that when I wear glasses my perception of a face starts at the glasses. But why does it not start at the cornea, which is in fact our main refracting organ. If my mother has thick glasses to correct for removal of her own lenses because of cataracts where are we then? 

For the radio you choose the vibration of the speakers. But why? We think we are hearing nellie, not speakers. You might argue that the speakers are where the 'sound ' starts. However the speakers are undergoing a certain type of transverse diaphragmatic oscillation that is distinct from the linear compression wave in the air that is again distinct from the oscillation of the ear drum. They all come under sound for the layman, but not for any very good physical reason. Tranduction between these forms of oscialltion is not that different from other transductions from Nellie to record to tape to CD to circuits in the player etc etc. 

Moreover, if we say that the start is where the information is transduced into the form that is to impinge on the sense organ we have trouble with our optical examples becasue they all start at the sun or a light bulb. The whole thing is a complete mess. There are no starts. There are no actualities out there that are simulated by the actuality of experience. We have to face up to leibniz I am afraid!

2010-06-04
The time-lag argument for the representational theory of perception
Hello Derrick,

When I revisit this time-lag argument it puts me in mind of Galileo's example of a perceived event in his work, The Two Great Systems of the World. A stone dropped from the top of a ship's mast will fall to the deck in a straight line, but as the ship is moving at, say, ten knots east to west, the stone will have traveled in a slightly curved line from the point of view of witnesses on the shore. Obviously the shape of the stone's journey has many versions depending on the viewer's Cartesian coordinate system. The earth is spinning at nearly a thousand miles per hour, etc. The point is that ultimately there is no single privileged view.

There is also the traditional philosophical question of whether there are mind-independent objects. We might expand on this line of thinking to address the time-lag notion of perception.  All objects are also in a sense events.  In fact they are best described as events. I would take Galileo's thought experiment as demonstrating that there are no such things as events without observers to perceive them.  We cannot ask for a single 'absolute' answer to the shape of the stone's true journey. The question is incoherent. 

All events, from my hand here to the most distant galaxy are regional appearances that take place in regional observers like myself.  Distance is their making, so to speak.  If observation is what ultimately 'constitutes' an event then it doesn't seem to make sense to say that I am always seeing things slightly out of date.  It is not so much that visual information 'travels' from the eye to the visual areas of one's brain. It seems to be more the case that the visual information's arrival at its destination is what qualifies it as 'visual information' at all.

Many thanks for an interesting topic.

Phil Dubuque          

2010-06-04
The time-lag argument for the representational theory of perception
To Derrick.

Sorry I never replied to your question of whether I should not count a sense perception as re-presentation, since it was earlier presented to the retina. (This thread is so long now that one can easily miss bits of it.) What causes the retinal image is not "presented" to a conscious perceiver, so no, it has not been earlier presented to any mind.I have no access to my retinal images.
I also apologize for misnumbering the step in your argument which referred to mental representations. It was step 4, not step 3. I still think that sense perceptions should not be put on the same level as real re-presentations (or of pre-presentations) since they are as direct as we get to what is happening around us, even if that is ever so slightly out of date. Thanks for the stimulus, Annette Baier.



2010-06-04
The time-lag argument for the representational theory of perception

Annette, I am glad you brought up the topic of whether sense perception might represent the retinal image.  I'm not sure why one would think it is.  I think vision scientists used to think that vision consists in extracting information from the retinal image and producing a representation of a 3-d world.  This is, roughly, Marr in 1982. 

I don't really know how many vision scientists accept that picture any more.  It seems generally agreed that there's a lot of that gets lost and a lot that gets added to our visual knowledge; our visual knowledge of a scene is the product typically of successive takes on bits of it along with lots of useful neural processing and all sorts of knowledge that we cheerfully put into the contents of our statements about what we see.  In a way it's got to be a truism that since it all takes time, we put together pieces with, as it were, different dates.  And we do not have dates in our descriptions of what we see.
 
That doesn't mean that our description of what we see is really a descrption of some other thing, a mental thing.  It looks as though our visual knowledge is made available to us by all sorts of elements which neither singly nor jointly are anything like a mental photo.  On such a view we end up with is knowledge at time t, not a unified experience at time t.  What's unified is our knowledge (or so one hopes) and our environment.  Or so it seems to me now. 

If this is right, then the time-lag argument does not establish that there is some out of date internal representation unless one starts with the view that vision is to give us some one mental representation of our environment.  And from this point of view, the problems with the time-lag argument starts with premise two and are compounded with the move to premise three. 

Annette, sorry not to engage your points more!  I think each of us is trying to undercut the need for seeing vision providing mental representations.  If I'm understanding it, you are arguing against an appropriate of terminology and I'm arguing against a picture of perception.




2010-06-07
The time-lag argument for the representational theory of perception
This post contains several replies.

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Hi Annette (see also second reply below)

You wrote:
if seeing is as direct as we get, more direct than say memory or seeing something reflected in a mirror, then even if there is time lag, sense perception is our directest access to what is there.
True, but the question is whether the 'directest access to what is there' is ultimately direct or indirect access. And if vision is merely a 3D mental representation, then that is contrary to common sense.
Derrick thinks it represents our surroundings as they were was at least .1 of a second ago, an interval which does not exceed that included in the specious present, the smallest junk of time we can discriminate in consciousness.
True, although the specious present is merely our subjective sense of what constitutes 'now', whereas the argument is referring to the objective present, which is the instant in time which separates the past from the future. Indeed, a duration of time can always be divided into earlier and later parts, and so a duration of time cannot all be in the present.

--------------------------------------------------------

Hi Jason

I'm afraid that I don't follow your position. You said above that you agree with me that a person with severed optic nerves would not have any visual experience at all. Why precisely do you believe that the severing of the optic nerves prevents a person from having any kind of visual experience? I myself believe this to be so because a person's visual experience is dependent on visual information from the eyes reaching the brain via the optic nerve, which takes time.

------------------------------------------------------

Hi Jo

You wrote:
Trouble is, Derrick, that your choices of 'starts' for perceptions are arbitrary and based on folk physics (not even some 'physics-free' a priori rationale) rather than anything consistent. 
I don't believe that what I take to be the start of the perceptual process is my choice, or arbitrary, or based on folk physics, or inconsistent. I take the start of the perceptual process to be the point in space and time that you are experiencing (albeit indirectly). As I said above, when you see an oak tree, you do indeed experience the oak tree, and not the acorn from which it grew, or the Big Bang explosion (you could argue that the oak tree is a remnant of the explosion, but that's still not the same thing as the explosion itself).
Let's look at the rainbow. I do not think this is an illusion in the sense that it seems to be something it is not.
But there isn't really a multicoloured arc of light in the sky, even though this is what we experience. For example, if there were, then it would be possible to see a rainbow from any angle, just as we can see a lighthouse beam from any angle, but when we can only see it from certain angles.
Is the blueness of sky an illusion?
Yes - we don't see the land from space through a blue haze.
If you follow this further you find everything is an illusion in some sense
I don't see why.
nothing exists at a point in space
The oak tree does - or, to be more accurate, it exists at several points in space, given that it's a three-dimensional object.
Where does the perception of a red setting sun start if the redness is the effect of diffraction across a hundred miles of atmosphere.
When I say that the start of the perceptual process is the point in space and time that you are experiencing, I wasn't meaning, in the case of space, 'point' in the sense of a literal mathematical point. That is, it would be more accurate to say that the start of the perceptual process to be the area in space, and the point in time, that you are experiencing, but this wording is more cumbersome.
Why does perception start at the mirror for the reflection.
Contrary to what I said earlier, I would say that the scene being reflected is the start of the perceptual process when looking at a scene in a mirror.
Reflection and refraction are fairly similar in basic physics. That ought to mean that when I wear glasses my perception of a face starts at the glasses.
Given my above change of mind, I would say that the start of perceptual process is the scene that you are seeing via your glasses (and via the lens in your eyes).
For the radio you choose the vibration of the speakers.
I actually said that it is the sound waves emanating from the vibrating speakers that is the start of the perceptual process.
But why?
Because we hear sound, but we don't hear the sound emanating from the singer's mouth because it was converted into patterns of electrical impulses during the recording process.
Moreover, if we say that the start is where the information is transduced into the form that is to impinge on the sense organ we have trouble with our optical examples becasue they all start at the sun or a light bulb.
I'm saying that the start is the point in space and time that we experience, and even though the oak tree is illuminated by the sun, we see the tree illuminated by sunlight, and not the sun itself.

------------------------------------------------------

Hi Phil

You wrote:
All objects are also in a sense events.  In fact they are best described as events. I would take Galileo's thought experiment as demonstrating that there are no such things as events without observers to perceive them.
I don't think that G's thought experiment supports the conclusion that there are no such things as mind-independent events/objects, as the thought experiment seems to depend on a mind-independent falling object, as well as a mind-independent boat, and sea, etc.


-------------------------------------------------------

Hello again Annette

Wouldn't you agree that a photograph of a scene that you have never seen before is still, from your point of view, a representation of that scene? In the same way, the visual image that I am arguing for is a mental representation of the scene that was presented to the eyeballs.

-------------------------------------------------------



2010-06-19
The time-lag argument for the representational theory of perception

Yes, Derrick, the photograph of a place I have never seen is a represenation, never before presented to me, but it was presented to the photographer, to some conscious perceiver. What I now see is mediated by what impinged on my retina a spit second ago, and what my brain processed, but it was never before presented to a conscious perceiver,so I would not call that a re-presentation. But I grant you that many others use the term "representation" for anything with informational content, and this use is becoming standard, so I am fighting a hopeless fbattle. You grant sense perception is as direct as we get, in the way of access to our environment, but think it is still indirect because of the earlier retinal image (or sequence of them) and what the brain makes of that. But neither the eyes or the bit of the brain that does the processing perceives: only the conscious person does, so there is no more direct knowledge behind the knowledge we get in sense perception. Its not second hand, like the photograph or what we accept from other's testimony. What interests me about what we get in sense perception is how its "conceptual content" (which we could verbalize) relates to what has been called its "scenario" content, which a photograph may represent better than any verbal description. But that's a long, and a different story.  Cheers,   Annette


2010-06-19
The time-lag argument for the representational theory of perception
Your "Time Lag Argument" is actually asking whether the events in experience are the same as events that might be measured in the world beyond the body.  By "same" I mean that the events have identical spatial and temporal coordinates and are composed of identical material at those points in the world.  You are claiming that the temporal coordinates of the events in your experience are by definition different from those of events in the world because they are the result of signals, indeed, they are signals rather than the source of these signals. 

Many of your respondents then attack this approach by either suggesting that the signals are in some way identical to events in the world because of reference or relations to these events or, bizarrely, suggest that space and time do not exist with statements such as experience: ".. is an actuality determined by the operation of instances of dynamic laws that are real and concrete but unenvisageable as 'stuff in a space'." (Bizarre because "dynamics" is the study of state changes in a geometrical manifold that has space and time).

My response is that the signals that compose experience are, by definition, different from the events that created them and the temporal discrepancy between the signal and the event that created it is just one of many differences.  The events that are related to the signals are indeed events in the world, if people wish to use this relationship as a definition of "identity" between the signals and the events that produced them then they are redefining the word "identity".

The type of Direct realism in which events in experience are held to be identical to events in the world, is either a redefinition of "identity" such as discussed above or a misunderstanding of physical science.  The detaching of "dynamics" from space and time is an example of the latter. Another example of such misunderstandings is the way that the physical world beyond the body is simplified by some philosophers so that it corresponds to "experience" for instance, the blue part of solar radiation that is not absorbed by an object becomes a property of a "blue" object, the pattern of impulses from skin receptors becomes the property of a "rough" object etc. Indeed, almost every "property" of an object in experience is not really a native property of an object in the world.  The time lag can be put together with other features of experience such as its spatial layout to provide a description of experience as a pattern of events within a projective geometry that is centred in the region of our heads, a layout that is useful for an entity that needs to move around the world, but experience is not the same as the native configuration of the events in the world that produced the signals in experience.

So what do I think of the article?  I think it is a good description of the "Time Lag Argument" but needs to incorporate responses to the multitude of ways in which philosophers have attempted to reject the discovery that experience is not much like the world itself.



2010-06-23
The time-lag argument for the representational theory of perception
The replies seem a bit wobbly Derrick. Not everything is an oak tree!
Maybe we need to get back to bizarre old Newton:


Sir Isaac Newton: Principia Mathematica (1687) 

SCHOLIUM ON ABSOLUTE SPACE AND TIME

1. Hitherto I have laid down the definitions of such words as are less known, and explained the sense in which I would have them to be understood in the following discourse. I do not define time, space, place and motion, as being well known to all. Only I must observe, that the vulgar conceive those quantities under no other notions but from the relation they bear to sensible objects. And thence arise certain prejudices, for the removing of which, it will be convenient to distinguish them into absolute and relative, true and apparent, mathematical and common. ...


I had hoped that when saying that we should not think of dynamics as 'envisageable stuff in space' that John would have realised that the meaning of space relevant to the context of 'envisageable stuff' would be Newton's 'common', to be distinguished from the 'mathematical' of his dynamics - the whole point of the comment. Where I tend to agree with John is that although Derrick's basic thesis is fine it seems to be no more than the standard scientific position minus the insights of 1687 (not to mention Montaigne and long before). Whether or not it is worth spending time trying to counter the objections of other philosophers who have not read Newton, I am unsure!


(PS. Whether Newton or Leibniz was right about absolute and relative space is another issue - Leibniz took the point about unenvisageable stuff more seriously than Newton.)




2010-06-23
The time-lag argument for the representational theory of perception
Is it not the case that, in just the same way that the notion of "the First World War" only makes sense in relation to "the Second World War", so it is that the notion of "indirect perception" only makes sense in relation to the notion of "direct perception". Now, if that's right, what is this direct perception of which you speak. Conversely, what is this indirect perception? If either term can only be defined with reference to the other what do the modifiers "direct" and "indirect" point to?

2010-06-23
The time-lag argument for the representational theory of perception
Derrick,

You asked, "Why precisely do you believe that the severing of the optic nerves prevents a person from having any kind of visual experience?"

I think if you reread my last post (post 3987), you will see that I do not believe this.  I think we should distinguish between visual experiences of the world (which require the eyes and optic nerves to be intact, because the eyes are the beginning of our visual response to the world, and the eyes wouldn't function if the optic nerves were severed) and some kind of experiences which might occur in the brain of a person who didn't have eyes or who had a severed optic nerves and yet which we might have reason to call "visual."

I have also indicated that a detached eye might have something we could call an experience, but that it wouldn't be a person's experience, because the eye itself does not constitute a person.

Regards,
Jason
June 22, 2010

2010-06-23
The time-lag argument for the representational theory of perception
Reply to Tom Griffiths
Dear Tom, Your comment is billed as a response to me and I apologise for this (a bit) if that was not intended.

You seem to be going down the road Newton warns against and Wittgenstein goes to town on around p55 of the Blue Book (which we were reading this afternoon), if confusingly, of calling on one supposed set of regular logical rules in natural language that it does not have. Does the notion that 'he kicked the bucket' only make sense in relation to 'he kicked x, where x is a bucket'? (An extreme example.) Philosophers should not play games with common language usage. Fortunately, I do not think that I (and I am not sure anyone) in this thread have mentioned 'indirect perception'. I have said that direct perception is a muddled idea and that the common view of perceiving things indirectly (note that the different form of the verb, with an implied object, changes the implications for meaning) is almost as bad because our intuitive idea of perceiving things already contains a category mistake in relation to (at least orthodox) physics. Indirect perception would be something I think I would want to keep clear of, at least in the current context, as I hope I made clear in one of my earliest responses.

Where I might agree with you is that our whole notion that we 'perceive things' is a pseudodynamic concept that is at odds with a usable dynamic description of the sort you get in a science lab and which should be perfectly acceptable and understandable to non-scientists interested in perception if they are prepared to accept that their intuitive view is full of category mistakes. There is a high order operational sense in which we perceive things like faces in mirrors. However, this relates to the very unusual way in which causal pathways are arranged in the brain to preserve correlations through many transductions and serve them up as 'things'. In a sense the object of our perception (where Derrick would want it to 'start') is a correlation which our sense organs are designed to preserve in subsequent pathways - except that to get that unambiguous in ordinary language would probably take two pages!!


Best wishes


Jo E

2010-06-26
The time-lag argument for the representational theory of perception
Jo E., what exactly do you mean by "dynamic"?  Do you mean objects changing position such as a simple motion or perhaps a change in relations between entities and/or between entities and attributes such as attaching "green" to "tree"?  I do not think that defining your meaning would take two pages, after all, most of the correspondents here are aware of elementary physics, logic and even rudimentary systems analysis.  It seems to me that the crux of your argument is that there is something complex about perception that means that direct or indirect realism are wrong and then you say that the reasons for this are too complex to explain.  Please explain "dynamic" and why your dynamic systems are unrelated to perceptual space yet explain it.

2010-06-27
The time-lag argument for the representational theory of perception

Dear JWKMM,

You ask: 'what exactly do you mean by "dynamic"?' 

I mean the standard physics or engineering definition, as per dictionary or Wikipedia.

'Do you mean objects changing position…?'

A dynamic account of 'change' is in terms of the dispositional properties of the world (forces, causes, instances of operation of laws of physics) that we use to explain our observational account of 'change', whether public kinematic or private experiential.

What I thought would take two pages would be a version of my account of the dynamics that we misconceive as 'perceiving things' that would deal with all the ambiguities inherent in the way we use language. The problem is not the complexity - it is the pitfalls of language. The basic problem is that a statement like 'the pendulum is swinging' can be intended as a dynamic, kinematic or experiential account and in normal discourse we infer which it is supposed to be by context. When we start talking philosophy we want to know which accounts do what and which are essential to our ontology and which just heuristic aids. We want the explanatory aspect of dynamics and the experiential, to me, is undeniable. The kinematic account, which is Derrick's Oak Tree Thing, is, however, recognised by physicists and neuropsychologists only as a practical prop. I would agree with those who see it as unparsimonious to say that there are internal and external versions of what things are like - and for me that fits with the fact that there is no other way that things 'are like' than our experience. All that is left are the concrete instances of operation of dynamic physical laws that populate the universe and that we know by their mathematical structure, not by their appearance. They are dispositional laws that determine how things appear to us, but in themselves they have no appearance.

Best wishes 

Jo

 


2010-06-27
The time-lag argument for the representational theory of perception
To Jo Edwards:

Why do you think that things do not appear dynamic to perceivers? What we see is change and motion, not a series of stills, static retinal images. Maybe we do not see what scientists like you take there to be really there, so there is a gap between appearance and reality, but surely the appearance can be dynamic. This thread is ever changing,and in its case I think it appears what it is, an ongoing conversation. Or do you take its real nature to be neurological processes, along with some electronic computewr processes? Dynamically yours, Annette Baier   

2010-06-27
The time-lag argument for the representational theory of perception
Hello all

I'm struggling to find the time at the moment to reply to the above posts, but in the meantime here is yet another version of the time-lag argument (I've lost track of which number this is!):


1) Your vision of an unilluminated scene being briefly illuminated by a camera flash is dependent on the light that is reflected off the scene travelling to your eyes and then being converted into electrical impulses, which must then travel to the visual areas of your brain and be processed, all of which takes about 100 milliseconds, with the duration of a camera flash being typically about 1 millisecond.

2) Therefore, this event occurring in your vision in the present in fact occurred wholly in the past, however recently:


3) But a past event, however recent, cannot itself occur in the present, by definition, although a representation of it can.

4) Therefore, your vision of the scene being briefly illuminated by the camera flash must be merely a mental representation of that event, generated by your brain from the information that it receives from your eyes.

5) If your vision of a briefly illuminated scene is merely a mental representation of that scene, then your vision of a constantly illuminated scene must also be merely a mental representation of that scene.


I'd be very interested to know what you think.

Best

Derrick

2010-06-27
The time-lag argument for the representational theory of perception
Dear Annette,
I feel slightly non-plussed by your misreading of what I said. I know I said it might take two pages to be ambiguity-proof but I find it quite hard to believe that it could be construed as you seem to.

Of course things appear dynamic, in the common experiential sense of the word. I said the 'dynamic account' is a description of what determines appearances rather than what appears. As I understand it it has been standard terminology in both science and philosophy of the seventeenth century for at least many decades, coming from the founders of physical science, Newton and Leibniz, both of whom took trouble to cover the philosophical import of their theories. I am not keen on 'terms of art' but this is standard and we do need some such a term. 


We see 'change', indeed. However, as Newton is at pains to point out this is not the change his equations deal with. He was quite clear that the space and time we sense things in are not the metrics of his laws. Are scientists supposed to apply a chap's equations to something he deliberately said they were not about? Interestingly, he assumed that his peers, if not ordinary people, would see the difference readily enough. I think academic debate may be narrower now. If we want practical evidence that the 'movement' we see is not Newton's motion, I find William James's collections of observations in PoP quite enough. I guess you not dispute that since you acknowledge the difference between 'appearance' and 'reality', which I prefer to call the realities of appearance and what is really going on that determines appearance. Both are concrete, instantiated and real, and descriptions of the same world, to my mind. 


I do find it a bit that my approach seems to be seen as 'a scientist's view'. What I am saying is, as far as I can see, the meat of seventeenth and eighteenth century philosophy. This is nothing to do with computers or anything new-fangled like that, it is just the basics of our testable theoretical framework for understanding the world. Derrick's original question is couched in the metrics of Newton's theories and is right in the middle of the potential conflation that Newton talks about. On whose authority should we throw away ideas that work and go back to the Middle Ages? 



Best wishes


Jo E


 

2010-06-28
The time-lag argument for the representational theory of perception
To Jon E.

I did not mean "scientist" as any sort of insult. Your profile makes you a scientist, as well as a philosopher. Nor did I mean by motion anything otehr than what Descartes and Leibniz took it to be, change of spatial position. I grant you that we do not see the forces scientists find, but we do see apples fall from trees, and trees buffeted by wind. I certainly want to learn from scientists,and as for authority as to whom to consult, its you who is charging the rest of us with category mistakes, not vice versa. I would like you to explain just what is pseudo-dynamic about ordinary talk of gravity, or wind power. Pseudo-dynamically yours, Annette B. 

2010-06-28
The time-lag argument for the representational theory of perception

Dear Annette,

The problem is not that motion is other than change of spatial position in any type of description, but that the spaces in the different descriptions are different. I am not sure about Descartes but Leibniz was certainly aware that 'apperceived space' is not the space metric of the laws of God.

What do I mean by pseudo-dynamic? All our dynamic, or explanatory, concepts are probably flawed. But it seems reasonable to distinguish 'dynamic concepts' that play out reliably, from 'pseudodynamic concepts' that we think of as dynamic/explanatory but which cannot play out because they do not actually have a capacity to explain. Ordinary talk of gravity causing apples to fall is fine for daily life even if Einstein showed that the mathematical structure of Newton's dynamics can be improved on. The fact that Newton's different sorts of space and time are ignored by most people does not matter here because the beauty of Newton's construct is that it defines an intermediary kinematic observational account which cancels out the events in brains and thus the need to worry about experiential space.

I think 'I see an apple falling' is significantly pseudodynamic because (amongst other things) it is unclear what 'see' means in terms of what is really going on - hence Derrick's original post. We start out thinking seeing is a bit like hitting. It is something 'active' which, as Leibniz points out, is an empty notion. We come to realize that seeing is receiving and, if anything, passive, except that it involves motor feedback mechanisms too. So 'I see an apple falling' is fine as a statement of experience but not much good as a dynamic explanatory statement. If I told someone to go off and make a machine that 'sees', they would immediately say 'what exactly do mean by 'see'.

As Derrick points out, what we experience as a 'falling apple' is an appearance determined most directly, necessarily and sufficiently by some dispositional dynamic properties of our brains. These dispositions are usually entrained by another package of instantiated dispositions we call 'an apple', although 'a video' might give a similar entrainment. We know that our experience of movement is not associated with any dispositional properties of the brain at all like the dispositional properties that are the apple. Metric space and time will be involved in both but not in an analogous way. Movement is encoded in the optic nerve in impulses whose time course need have nothing to do with the time course of the movement. There is no need for an experience of a time-taking event to need brain processes taking that amount of time.

A key point is that true explanations make use only of dispositional properties. Qualitative properties do not contribute. People constantly argue about the impossibility of 'qualia' contributing to explanations of how brains work. They seem to miss the corollary of this: that in the outside world 'what an apple is really like' cannot contribute to our experience of an apple. The experience can only be explained in terms of the dispositional properties of what is going on in an 'apple' domain of the world. The red experience is explained by a disposition to reflect long wavelength light, the 'movement' experience is determined by dispositions 'really going on' nearer and nearer the ground. Berkeley and Kant obviously had a lot to say about these things but in my view Newton and Leibniz had a simpler, more transparent, account, even if it may only be transparent to those who have already arrived at it themselves through familiarity with working with testable ideas.

This is getting long, but I will finish with a note about concepts, partly because I have been reading Rorty. To me a concept is again something with two meanings: dynamic and experiential. To have a concept of Jim is to have dispositions in one's brain that bring up a variety of images or associations in response to a face, name or voice etc. To have the concept of Jim also implies that one experiences these images or sounds in a particular relation. So maybe we might have in our field of attention a pattern of elements of experience that include a face, an inner voice saying 'Jim' and a sense of matching (someone might doubt that we can experience 'matching' but no experiences are what intuition says they are so I see no bigger problem). These experiences can give rise to various sentences, according to what is salient at the time: 'Yes, that's Jim', 'I know Jim', 'Jim still looks young'.

On this basis a dynamic concept is probably one in which the brain dynamics set off by the word of the concept parallel goings on in the outside world in some mathematical way, based on the fact that brain dynamics are just microcosmal world dynamics. A pseudodynamic concept is one for which the brain dynamics entrained get hijacked by arbitrary labelling associations (the old 'a Perrier and water please' situation) or by deeply ingrained intuitions that seem to be dynamic and are not - like agency or belonging.

That's already too long

Best wishes

Jo (not Jon for me, right first time)

 


2010-06-28
The time-lag argument for the representational theory of perception
Thanks, Jo, and sorry about the name muddle. But I do not understand why you think true explanations are in terms of only dispositonal properties. Of course such properties matter, but the sun's disposition to warm bodies in its vicinity, to attract smaller bodies, etc does surely lie in its own nature, as a ball of fire, with a certain mass. Or do you not use the concepts of mass and matter? Ordinary understanding of what it is to see may exaggerate how up to date the information we get is, but by taking it to be the outcome of a process involving eyes, brain, and outer world seems to me plain dynamic, not pseudo dynamic. But it does suppose there are such things as eyes and brain and world, with lasting non-dispositional properties as well as dispositional ones. My gums have a disposition to blister, but that is because I have an autoimmune disease, which alas is a permanent feature of me, the basis for the disposition. And I am prone to infection, since I lost my spleen, but that last absence is non-dispositional. Enough, too much, of me,    Annette.  

2010-06-29
The time-lag argument for the representational theory of perception

Dear Annette,

Your question goes to the heart of my reservation about Derrick's exposition. I have been propounding some received wisdom in natural science but also a few of my own interpolations, I admit. I would like to try to justify my claim that 'true explanations are in terms only of dispositional properties' because I am quite interested to see whether it can stand up to philosophical scrutiny.

What would count as 'own nature' properties - you intimate mass or matter. Maybe we can add Descartes's extension? My memory is that Descartes defines extension as a disposition to exclude other things from a domain of space. Newton defines mass in terms of inertia, or the disposition to resist accelerating in the face of force. He finds this disposition is always accompanied by a disposition to attract other masses. Einstein calls this a disposition to curve spacetime. Einstein also shows earlier that mass and energy are interchangeable. Descartes's extension finally turns out to be a disposition related to the Fermi statistics of certain energy packets. It is all very dispositional and I am pretty sure that Newton never wanted mass to mean 'stuff'. Matter is whatever concrete instantiated entities we have in the world but all that we know of these entities are their dispositions. Or so I think.

Let us posit a non-dispositional, maybe qualitative, property Q that is the 'nature' of some concrete entity. I would argue that we can only know of Q because it is associated with at least one disposition D to affect experiences in us or others. I have no problem if disposition D is never proven to be realized. I am quite happy to accept Q and D even if it is just parsimonious to infer their existence . However, if there is no such putative disposition D, Q is redundant. There is no possible way of knowing if the nature is Q, or Q and P, or P, X and J. We are allowed to be positivist here. Moreover, in all the Q candidate cases we are interested in we do have associated dispositions.

So if we say that the evidence we have through disposition D is of a nature Q then we ought to be able to define the relation between Q and D. Unless Q is 'prior to D', 'causes D' or 'D can be attributed to Q' Q has no explanatory role and goes back to being redundant. If Q is the origin of D then I think it is fair to say that Q must include the dispositional property d of entailing D, and that this dispositional property d of Q is the only aspect that is not redundant to an explanatory account. We then find that the distinction between d and D is redundant and so we are back to just wanting D. It seems that where the buck stops in an explanatory account has to be a D (as per Leibniz's dynamism).

A potential spanner in this works is where we find two dispositions Di and Dg, as in inertia and gravitation that are always associated and in proportion. What is the relation between these if there is no Qmass to entail both? I think one answer is that the arguments above indicate that it is a Dmass, not a Qmass. The other is that science works hard and often successfully to show that Di and Dg are two expected manifestations of a single Dmass. In this particular case not yet.

So I guess that my claim is that your 'lasting non-dispositional properties' must be lasting dispositional properties, at least to be any use in explanation (which of course Wittgenstein says philosophers must never get involved in anyway!). That is why I tend to think of the world as being populated not by things but by concrete (often long-lasting) instances of operation of the laws of physics. I guess I am at odds with Leibniz here, since his monads were merely guided by these laws. Nevertheless, the monads had no properties other than a disposition to be guided by these laws, save of course perception, but perception does not form part of an explanation of what goes on, it only figures as the end result of goings on.

Jo


2010-06-29
The time-lag argument for the representational theory of perception

Dear Jo, Are you a closet Berkelyan? Is the world just the permament possibility of ideas in observers? Your case for making dispositions fundamental explainers involved reference to our observations of things, thus reducing the sun's heat (Q) to its disposition to warm me and the things I can feel (Ds) But even for Berkeley minds are more than dispositions to have ideas and volitions. Do you understand yourself as just a heap of dispositions? Ryle, the inventor of category mistakes, wrote well on dispositions, and his account of what it is to have a mind does employ behavioral dispositions, instead of Cartesian thinking substances. But episodes have to be real for talk about dispositions to make sense. My typing this message is an episode, a real happening, even if it does also display my disposition to argue. Episodically yours, Annette

PS Descartes did have a substance ontology, and lacked any concept of force, which was why Leibniz thought he needed correction, and his conservation law was faulty. Are forces, for you, just dispositions to act in certain ways in certain circumstances? Is anything conserved in the universe as you understand it?  


2010-06-30
The time-lag argument for the representational theory of perception

Dear Annette,

Firstly, I note that you offer no counterarguments to those of my last post.

My copy of Berkeley has about two margin notes, indicating that I think 98% of what he says is valid but that just occasionally he gives it away that he is throwing the baby out with the bathwater. I am not a Berkeleyan, but might not hide in a closet if I were - there are some weirder ideas on this forum.

A: 'Is the world just the permanent possibility of ideas in observers?'

J:That will depend on how you define idea and observer, but if we assume that these refer to biological entities then no. I am saying that the world is populated with concrete (i.e. instantiated) entities in the sense of Cartesian substances but that the only intrinsic properties of these must be dispositional (as argued in last post - excluding an infinity of unparsimonious ineffable Spinozan properties). One disposition may be to experience (arguably 'cogito' but I admit there are complexities there). The more general type of disposition will be that we call a physical property or instance of operation of a physical law. This latter type will entrain all the known interactions in the universe including any that come with 'experience' only if appropriate substances are around.

Perhaps I could ask what non-dispositional properties you are wanting to preserve. We have done mass and matter. Heat is either a relational (not intrinsic) and dispositional property that is the causing of a sensation in us or it is a rather complicated statistical derivative of motion, which is again relational and dispositional. So yes, I do understand myself as a heap of dispositions but in no way want to go off in a Rylean direction (heaven forbid). 'I' refers to an experiencing substance. And I agree that episodes have to be real. They are part of what is really going on, which is the playing out of dispositions to entrain 'episodes'. But the only thing we know episodes, qua 'actual events' to consist of is something that for us is an experience. What it is in other cases is ineffable but it cannot be an intrinsic property of anything because an episode is a determinate relation. (Modern physics has confirmed empirically that without a relation of interaction there is no fact of the matter about any property. Again I am not sure what non-dispositional intrinsic properties you are thinking of but qualitative properties would have to be relational.)

Forces are probably old hat. Modern physics is much closer to the Monadology with progression in harmony. Leibnizian dynamism is often talked of in terms of forces but my impression is that by 1714 he had moved on to 1925. The conservation laws work fine because all physical laws are couched in dispositional terms.

Best wishes

Jo


2010-06-30
The time-lag argument for the representational theory of perception
Dear Jo, you ask which non-dispositional properties I am keen to preserve. I take the fact that I am a living being, with a certain size, shape and weight to be such properties. And my consciousness also seems a fairly fundamental property of me. Or do you take life just to be the disposition to breathe, ingest noursihment etc, consciousness no more than the disposition to sense and think?  I am no physicist, but I take the charge of a particle, and its spin, to be non-dispositional. I am glad to hear that you like what Berkeley wrote. As my favorite, Hume, said, his arguments admit of no answer, but produce no conviction. This thread began with claims about vision, and I take both my eyes and my brain to have a shape, a chemical composition, etc, which explains what they do, the dispositions they display, as long as they are part of a living being. Surely the cells you examined had some nature which explained their dispositional properties. Best wishes, Annette Baier.   

2010-07-01
The time-lag argument for the representational theory of perception

Dear Annette,

I sympathise with your wish to hold fast to intuitive concepts but:

So I am told, around 1485, Christoffa Corombo approached the Portuguese hoping for a grant to find a way to India. The Portuguese sent him away because they knew his figures for the size of the earth were out by miles and that even to get to Japan would take forever. Portuguese mariners had known for centuries that the earth was round and in commercially secret trips to Canada they had documented the size of the earth precisely. Yet even when I was a boy I was taught that in the fifteenth century people thought the earth was flat. A lot probably did, just as  George Bush thought Nigeria was a continent. Moreover, this was encouraged by the 'philosophers' of the church. But some people had checked out the real situation.

The question is whether, in trying to assess Derrick's proposal, we throw away 500 years of progress in human thought or whether we check out the real situation. You say that Annette is a living being. You can check out that you can have a real experience of Annette in the mirror. You know that science can tell you in detail how that experience comes about through real instances of operation of laws. But there is no firm basis for suggesting that in addition to these operations of laws and your experience there is a misty ineffable 'Annette' that is 'really out there and really like something even if I cannot see exactly like what with my eyes at the moment'. This historic or kinematic Annette concept is a construct of the way the human mind computes, and we know a reasonable amount about where some of that computation is housed in the inferior temporal lobe, but as far as we know, no more. The issue is not whether it is unparsimonious to posit mental representations as well as objects. It is whether it is non-parsimonious to posit (kinematic) objects. To my mind, Leibnniz was clear on this and his account holds up 300 years later:

Dynamic Annette is an aggregate of monadic units (not billiard ball atoms) varying from electrons up to really big things like modes of angular momentum, which in modern group theory are just as real as electrons. Their only intrinsic properties are their dispositions to progress according to laws of nature. Size and shape are features of extension and reflect the interactions between monadic elements both in terms of Fermi-based exclusion and Bose-based adhesion. The a priori conclusion that these are not intrinsic arrived at by Leibniz is now confirmed by Einstein - there is no fact of the matter what the size and shape of (kinematic) Annette are - they depend on the frame of reference of another observer. Weight is clearly not intrinsic because in a spaceship Annette would be weightless. Chemistry is entirely dispositional. In fact there was no explanatory theory of chemistry possible until modern physics showed that there is no fact of the matter about where 'valency hooks' are. Valency is pure disposition. Charge is defined in terms of the disposition to repel or attract. Nobody has ever found any other non-dispositional feature of charge. Nothing non-dispositional can ultimately explain dispositions for the reasons given in my original post on this. All explanations are in terms of dispositions. I am pretty sure of that. Otherwise they are just labeling exercises.

Best wishes

Jo


2010-07-01
The time-lag argument for the representational theory of perception
Dear Jo,
At my age and decrepitude, I avoid mirrors as much as possible, but do not need them to know that I am here, and not at all ineffable. You seem to dislike stuff with qualities in space, preferring kinematic goings on. I am unsure, even after consulting your earlier posts, how you decide what is and is not a dispositional property. My seeing what I type is actual, not any sort of disposition. One of your earlier posts referred to the big bang. Did it have only dispositional properties? You also  refer to the laws of God, but who knows what you mean by that word-- the meta disposition determining all other dispositions? A few definitions might help the debate. Best wishes, Annette

2010-07-02
The time-lag argument for the representational theory of perception
We have probably played this one through but to answer all those last questions: I do not doubt at all that the Annette of your experience is effable. What I am doubting is that this is an experience that either represents or just presents an analogous 'objective' out there Annette. I dislike stuff but am very happy with qualities in experiential space. I eschew the kinematic, preferring the dynamic, which is what is really going on and as real as the actual experiences. Yes, the big bang is the beginning of all real dynamic goings on with only dispositional properties. I refer to the laws of God only in deference to direct translation of Leibniz. For me they are just the laws of our universe. As we know them they are just the dispositional laws they are. As to whether there is some ultimate meta-disposition I am neutral. The definitions are out there - mostly on Wikipedia in fact! 
I did enjoy the exchange though. 

2010-07-03
The time-lag argument for the representational theory of perception
Hi Jo,

In Wikipedia it states that "the study of the causes of motion and changes in motion is dynamics".  I have described the modern physical idea of dynamics in the note below.

When I read neurophysiological accounts it is clear to me that the authors find it unnecessary to include dynamical accounts of events, instead they catalogue the succession of events.  This is good enough for what they are seeking to achieve in their profession but I doubt that many of them actually understand the underlying physics of the events that they observe.

Our experience itself requires a different level of physical analysis from that used by biological researchers. This is obvious the moment we ask how we can "see".  The first "image" that occurs between ourselves and the objects around us is created by the lens system of the eye.  According to simple theories of dynamics it is immediately clear that this image on the retina can only be "seen" if it is transferred elsewhere but then it would form another image that can only be "seen" if it is transferred elsewhere... this regress shows that:

Simple theories of dynamics are false

Of course, we know that anyway - see note below.

Annette said: "Why do you think that things do not appear dynamic to perceivers?" and notes we perceive movement and change. I agree, as did Aristotle, Descartes, Whitehead etc.  Our experience is a complex manifold of events arranged in both space and time that occur in our brains and it will need complex, modern, physical theories to explain it.  Most importantly we should not give up, we should not dismiss an observation that occurs in almost every human being, our experience, and just say that:

"All that is left are the concrete instances of operation of dynamic physical laws that populate the universe and that we know by their mathematical structure, not by their appearance."

It is the "appearance" that we are trying to explain, it exists, just look around and listen to whole, time extended bars of tunes and simultaneous patches of colour.  We cannot just argue away this observation on the basis of theory. That would be unscientific.

Note: There may be some linguistic difficulties in treating dynamics but let me simplify it.  Dynamics is the change of one 3D set of objects into another 3D set with a different arrangement.  Modern dynamics entails a "frame of reference", a coordinate system that describes a 3D set of objects in which there is no net relative motion between the parts.  The physical "laws" of dynamics are dependent upon the idea of "kinetic energy", a relativistic term that arises because a massive object has clocks that cannot remain synchronised with those in a different frame of reference.  The path of such a moving object is dictated by Quantum Electrodynamics in which all possible paths in space and in time interfere with each other.

2010-07-03
The time-lag argument for the representational theory of perception
Jo: "The problem is not that motion is other than change of spatial position in any type of description, but that the spaces in the different descriptions are different. I am not sure about Descartes but Leibniz was certainly aware that 'apperceived space' is not the space metric ... (expand) of the laws of God."

Will this idea of a special space for perception solve anything? The problem with simple dynamical theories is a problem with time rather than a problem with space. Your idea that "spaces in the different descriptions are different" does not resolve the problem of experience, it just transfers it to another place, there still remains the central problem of time. If events are frozen in space at any instant and "knowing" is a process then we can only "know" in the next instant, never now.  As I noted before, this model of time in simple dynamics does not permit our experience so must be wrong.  Fortunately we hear words extended in time and see movements so real dynamics in the real world is more than a succession of frozen instants 

In confirmation of the problem being with time rather than with space you mention "dispositional properties", the tendency to be involved in an action.  Brentano used a similar approach by defining intentions and I would agree, our experience contains directed actions. An action is a spatio-temporal form (objects arranged in time as well as space).  However, if we use an analysis in which time is a succession of spaces we cannot explain how actions become part of experience because experience is then no more than a frozen 3D form when it happens. The only way out of this impasse is to consider the possibility that space and time are dimensional (extended and independent) so that events can then be extended in time at one place and also at a point at another.  The "metric of the laws of God" permits this duality because dimensional time enters as a negative quantity allowing events to be both projected and at a point (ie: the metric of the universe is ds^2 = dr^2 - cdt^2).

I agree that concepts are central to our experience. "Concepts" are processed in the Turing Machine of the non-conscious brain and placed in the manifold of events that we call "experience" where they become known as a result of being time extended entities.  Why the machine of the brain needs to place its output in a spatio-temporal manifold that we call "experience" is mysterious but remove experience from a person and they cannot do much.

2010-07-03
The time-lag argument for the representational theory of perception
Dear Jo,

Isn't the aim of science to find the relations between phenomena?  Annette is saying that she has a phenomenon that is unexplained, I say the same.  This phenomenon has extension and content, our scientific task must surely be to relate this extension and content to measurable phenomena.  If this takes us through QM or other relations that's OK but I cannot find any attempt in your comments to explain any relations that might describe the phenomenon that Annette and I experience. In fact you seem to be on the verge of simply dismissing the phenomenon that I am sure I have on the weak basis of arguments that the world is really a bit complicated.  Let us start at the phenomenon, our experience, and attempt to find relations within it and between it and the physical brain, we will then be able, in the long run, to relate the phenomenon to the physical world of measurements.

I cannot find in any of your comments a clear argument why we should believe that our experience does not exist.  If it exists I cannot find a clear argument about why it does not have extent and content - the obvious features of its existence. You say experience might all be dispositions or computations but you miss the essential relation between its phenomenal character and these physical phenomena.  How exactly does a computation become an extension in experience, how exactly does a disposition become green?  Computations and dispositions do not even have the right units to be used in such relations!


John

2010-08-29
The time-lag argument for the representational theory of perception
Your argument reminds me of G.E. Moore's argument for "sense data", which went something like this: "hold your hand up in front of your face; you will agree that you do not see your hand, but merely the surface of your hand". I'm not saying that the two arguments are alike in content, but they have the same intent: to show that we cannot perceive the world "directly". Just as Moore could not see the bones and blood vessels inside his hand, and thus could not really see his hand, so you cannot "directly" see the hand of the present, but merely a representation of the state of your hand at some remove in the past. 

A difficulty with both arguments is that in order to argue that one cannot see "directly", one must have some sort of idea of what it would be like to see in this manner; we have to at least have a notion of what is being falsified if the argument carries. In Moore's case, we have the altogether weird assumption that, in order to directly see a thing, we must see all parts of it at once. In your case, we have the requirement that things seen directly must be seen without delay.

You seem to be troubled by the delay that occurs once your visual responsibilities begin--that is, the moment at which light strikes your eye. But what about the delay that occurs before light reaches you? As you know, the stars are so distant from us that the light from even the nearest ones takes years to reach us. Obviously, we cannot ever see stars directly, according to your argument. However, now that we have been reminded of the finite speed of light by gazing at the heavens, does this not have some rather obvious consequences when we gaze at objects located very much nearer to our eyes?

After all, delay is delay. If the requirement that we see something directly is that we see it right now, then a delay of even a fraction of a femtosecond is fatal. Light simply doesn't have a chance of acquainting us directly with the world around us, and our vision must fall short of directness. Moreover, the fault lies not in our senses (well, not the first fault), but in the universe itself: even if our eyes and brains were infinitely fast, we would be condemned to viewing historical facts only.

My conclusion is not that your argument is wrong, but that it is superfluous: if the opposite of the "representational notion of perception" is defined as "seeing things instantly", then the universe just won't allow it. Now that I think on it, if your requirement for non-representational perception is indeed that it must be instantaneous, doesn't that put you in some sort of difficulty with special relativity? --Not that I would know; I'm just asking.






2010-08-30
The time-lag argument for the representational theory of perception
Thanks, Peter Cash, for your sensible remarks. There is no point in bemoaning the fact that the directest knowldege we can get, by vision, is a bit out of date. What does it matter? Would touch or taste give us more up to date information? I repeat what I have said before, that "representation" should be reserved for what really is re-presented, and what is presented for the first time, even if slightly out of date, can be called "presentation," or direct knowedge. Thanks, Annette Baier   

2010-08-30
The time-lag argument for the representational theory of perception
Annette, I fear that--as always--I have been far too elliptical. My comment was intended as a friendly reductio ad absurdum. Perhaps absurdity survives electronic transmission about as well as irony and most forms of humor in general.

Of course I'm not bemoaning anything. I'm saying that if a few microseconds matter, then nano- or even femtoseconds matter also. Please note the hypothetical. I am saying nothing more than that the original argument has a very peculiar focus, and that the requirements for "direct" perception are absurd.

"What does it matter?" Indeed! Precisely! (In other words, I think we agree.)

2010-08-30
The time-lag argument for the representational theory of perception
Dear Peter, I think the elliptical message must have been mine, since of course I did not take you to be taking the timelag argument seriously, or bemoaning anything. I should not have brought in the other senses, where the only lag may be due to brain processing. Maybe I find humor hard to take here, as I have an auto immune disease which, if it spreads to the eyes, will blind me. I take vision to be a great wonder, whatever the time lag, and appreciate every sight I see. Berkeley's taking what we see as a language telling us what we can feel if we get close enough seems dead wrong to me. The blind "see" by touch--that is what they feel is indeed a language by which they work out what is there to be seen, but it can never represent it adequately. Touch is a crude sense, compared with sight. If it gives us more "direct" a contact with what is out there than sight does, it is a lot less informative. Sound is also a rich sense, and artists exploit both the visible and the audible. Not many scultors want us to run our hands over their sculptures, but I suppose there may be some touchy-feely artworks. Philosophers do not do enough comparative sensory investigation. And we all tend to overconcentrate on sight, when thinking about senseperception. Hume's "impressions" are usually taken as visual ones, though in theory they need not be. Some, such as Donald Ainslie, take them to have "image content" though how sound or taste could have that is most unclear. And for touch to give us images, we'd need to be able to do what the blind may do, convert tactual content into visual, or pseudo-visual. But enough, Thanks, Annette B.    

2010-08-31
The time-lag argument for the representational theory of perception
Annette,

First of all, I'd like to thank you for replying to me at all. My usual experience as a philosopher has been that everyone pretty much ignores me. (Sad to say, I must consider the very likely possibility that there is a good reason for this, but I suspect there's not much I can--or want to--do about it.)

I don't think your mention of the other senses was a wrong move at all--in fact, it was precisely the correct one. As you correctly observed, Philosophers talk about "the senses"--but they really spend almost all their time talking about vision. My own dissertation--may it rest in well-deserved obscurity--concerned vision. Because of this exclusive focus, it may escape our notice that philosophical arguments concerning vision may not always be easily transferable to the "other" senses, or that conclusions derived from observations about vision may not apply to--for example--hearing.

In the present case, I wonder if Derrick would have proceeded as blithely, had he chosen hearing as the basis of his "time-lag" argument. We don't usually consider the time-lag imposed by the speed of light when we look across a room, but the tardiness of sound is well known, and comes into play when we observe such mundane effects as hearing thunder several seconds after the lightning that caused it. There is, in fact, considerably less delay caused by the neural mechanics of hearing than by relatively sedate velocity of sound--especially if the source is several miles away. I invite you--if you are so inclined--to think about the even greater difficulties raised by the senses of smell or touch in understanding Derrick's argument. It smells funny to me.

I was trying to peel Derrick away from his preoccupation with internal neural "processes", and get him to take a peek at the world. The universe has its own laws and peculiarities that must be taken into consideration when we talk about perceiving it. Specifically, I'm not at all convinced that I can make sense of the difference between the world of the present moment, and "representations of the past". Exactly what is the "present"? Is the present here in Munich the same as on Aldebaran or Vega? I don't want to pollute this philosophical discussion with mere science...but Einstein did have some things to say about "simultaneity" that pretty much make a hash of imagining a universe moving forward in time as a single unit. Time is...er...relative. So, perforce, is the notion of simultaneity.

Items 2 and 3 of Derrick's argument contain the implicit assumption that there is a "world of the present". This implies that our world is traveling as a unitary object (or collection of objects) through time. For this picture to make sense, we have to imagine that the present is the same everywhere--In London, in Munich, on Betelgeuse and on some star in the Greater Magellanic Cloud. This doesn't make any sense (to me, at least, and I think Einstein would have trouble also). Given that items 2 and 3 of the argument are muddled, I'm afraid the entire argument fails.

As for the virtues of humor, Annette, I cannot recommend them too highly. It's been advertised as a Medicine for Melancholy, and serves as a weapon to counter, for a time, the inevitable depredations of our own frail mortality. But of course, all humor is fundamentally gallows humor.

Smiles,
Peter

2010-08-31
The time-lag argument for the representational theory of perception
Thanks, Peter. I agree the present is over-rated. Iam perfectly happy living in the past, and i do not mind how distant it is. Is Derryck still reading this thread? It would be good to know if he thinks his argument works for other senses, Smiles, Annette

2010-09-02
The time-lag argument for the representational theory of perception
Relativity debars an actual universe because there is no such thing as simultaneous existence.
Jo, this is a philosophical assertion about what you imagine to be one of the consequences of Special Relativity; it is certainly nothing Einstein would have recognized as a corollary of his work. In fact, I'm quite sure he would be surprised to learn that his work had led anyone to the conclusion that "relativity debars an actual universe". Appalled, even.

If I understand it at all, your assertion implies that there must either be a universe that exists all at the same time (same time = simultaneously), or it follows that no "actual" universe exists at all. That isn't any part of relativity theory, it certainly was not proven by relativity theory or the various experiments that verified that theory. In fact, it's not an assertion that could possibly be proven or disproved by any branch of science known to me. It's simply a bald assertion of the peculiar type that philosophers sometimes make. It's customary to present an argument in support of such hypotheses. You might want to start by sorting out what you mean by "actual".

Your remarks struck me as interesting because I brought up the topic of "simultaneity" earlier on this thread without having read your remarks here and on your blog (I'm reading the thread backwards in time--sorry about that). I tried to argue that Derrick's original argument implied the notion of a simultaneously existing universe that moves forward in time as a unit. As I think you will agree, this is a simplistic Cartesian/Newtonian notion. (In your blog post, "Perceiving Perception and Seeing Seeing" you refer to it as the "Alexandrian" view.)  I felt that some simplistic notions about time, the universe, and everything were misleading Derrick. I argued that it's not necessary to suppose that everything must be perceived at the same time (or in some sort of instantaneous present) in order for our perception to be non-representational.

In my opinion, a more modern, relativistic world-view would be helpful in dissolving apparent paradoxes of the sort Derrick raised in his argument. However, you seem to think that "modern science" itself somehow disproves not only the representational view, but also the whole "actual" universe. That seems hasty.

2010-09-03
The time-lag argument for the representational theory of perception
Reply to Peter Cash
There is a very good Wikibook on Special Relativity.  It is available as a complete PDF. What is excellent about this book is that it clearly explains the modern idea of an Inertial Reference Frame as a slice through a four dimensional universe.  JoE's simultaneous existence is indeed clearly existent but is a slightly different slice for each observer.

No-one can doubt that relativity theory and quantum theory are incomplete.  Relativity describes a Block Universe and requires some source of "becoming" that is outside of space and time (See Vesselin Petkov. (2005) Is There an Alternative to the Block Universe View?) and Quantum theory is peculiar because it deals in probabilities that have no proper basis without the assumption of a Multiverse yet the Multiverse has never been observed. The Multiverse is especially weird because it is just so extraordinarily multiple, for instance, the entire universe is duplicated as entangled "environments" for all the possible positions of each single electron. 

It always amazes me that far more people are prepared to accept the incredible profligacy of modern quantum theory than are prepared to accept the existence of the time dimension in relativity theory. This cavalier rejection of time is particularly intellectually depressing when it is obvious that the events along any observer's worldline would be duplicated and existent in any Multiverse that is as infinitely infinite as that proposed by quantum theory.

2010-09-03
The time-lag argument for the representational theory of perception
Reply to Peter Cash
I agree with Derrick and I doubt that the pejorative term "preoccupied" is deserved. Talking of funny things, PC said:

"This implies that our world is traveling as a unitary object"

Surely it implies that the observer might have some simultaneity within their perception, not that the whole world is unitary.  In fact PC's reflections on Einstein are particularly timely.  In a (3+1)D universe each point has a set of simultaneous events and no two points have the same set.  It is also the case that there are sets of events that have a point outside the set for which they are simultaneous (eg: a 'view' occurs at the point of zero net separation in a 4D pseudo-Riemannian manifold).

Derrick's model would be false if subjective time and space bore no relationship to physical time and space. For instance, a view containing a representation of flowers in our minds might be a delusion and never even happen or the view containing a representation of flowers in our minds might have an entirely different form in the physical reality that creates it. If these possibilities were true then Derrick's model would be false.  However, it would be hugely premature to make this assumption whilst it is possible that ordinary physical effects such as projective geometry in a 4D manifold and events laid out somewhere in the brain could explain perception.  It is probably no joke that many neuroscientists take a Direct Realist stance and are not even looking for a substrate for conscious experience and, if they sit on funding bodies, would withhold funds because they consider the search to be absurd or impossible.

2010-09-05
The time-lag argument for the representational theory of perception
First, I must apologize, JWK, I wasn't ignoring you, I just didn't see this post (http://philpapers.org/post/4649) until just now.

I completely fail to understand the purpose of your quote of what I wrote; I can't tell what the following paragraph says because it is filled with technical terms that appear to be strung together in what could be a completely arbitrary way, as far as I'm concerned. Worse, I can't even tell why you think what I said was funny. I do so hate to miss a joke.

You say you agree with Derrick. I take that to mean that you think his argument carries, and that representationalism is true. As I said, I am not convinced by Derrick's argument because I think there is something incoherent in his temporal requirement for whether the world is "directly" seen. Derrick argues that if we cannot see the world as it exists right now, then we see it only indirectly (presumably as a "representation"). I assume that the contrasting case would be seeing the world without the delays imposed by the bio-mechanics of our senses. In other words, perceiver and perceived would be separated by no time at all--they would exist synchronously in time. If representationalism were false.

My argument was essentially that we could not see the world the way Derrick's argument suggests would be required for "direct" seeing even if we were to disregard the bio-mechanical delay. This is a result of the nature of the universe, which--as we now know--does not exist as a unitary object or collection of objects traveling in lock-step along the time axis.

Derrick's model would be false if subjective time and space bore no relationship to physical time and space.

Of course, I can't speak for Derrick, but I don't think you're helping him. As far as I know, he doesn't care about the relationship of "subjective" to "physical" space-time--at least as far as his argument goes. The purpose of his argument is to show that representationalism is true. His argument turns on the lack of identity between what is perceived and the perception. This non-identity allegedly comes about because of the delay that Derrick says is involved in perception. If, and only if, his argument carries can we even speak of the difference between "subjective" and "objective" space-time.

What you're offering to fix up Derrick's argument is a petitio. You're assuming representationalism is true, and you are giving an explanation of how such a representational model could work. That's premature.





2010-09-05
The time-lag argument for the representational theory of perception
JWK, I'm as familiar with special relativity as a non-physicist can be. Heck, I can't even ride in an elevator without wondering if I'm maybe actually traveling in an accelerating box in distant space. However, this doesn't help me to understand what you mean when you say stuff like "Relativity debars an actual universe because there is no such thing as simultaneous existence."  What do you mean by "actual"? Why can't the universe of Special Relativity be actual? What does it mean to be non-actual?

2010-09-06
The time-lag argument for the representational theory of perception
This thread seems to have wandered far off topic, but it may still be worth saying that it seems fairly plain to me that the original argument (given in the first post) is question begging. Step 2 seems to be based on the assumption that visual experience is some sort of product or effect of neural processing, something that can only arise after (some part of) the neural processing is done, and that assumption amounts to an indirect theory of perception (and, very likely, any coherent indirect theory is going to be a representational theory). A direct realist, however, will refuse to take the first step of agreeing that perceptual experience is a product or effect (of anything).

That is not to say that neural processing is not crucially involved in visual experience, but, instead of viewing it as a link in a causal chain leading from light striking the eyes to the creation of some sort of inner, experienceable representation, experienced at an instant somewhat later than the instant at which the relevant photons struck the retina, the direct realist will regard visual experience itself as a process (of which neural events form one crucial aspect) unfolding over time. There is no specific instant at which a visual experience happens, any more than there can be a specific instant at which we experience a melody.

Nigel Thomas
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WEB SITE: "Imagination, Mental Imagery, Consciousness, and Cognition: Scientific, Philosophical, and Historical Approaches."
http://www.imagery-imagination.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

2010-09-06
The time-lag argument for the representational theory of perception
Reply to Peter Cash
In answer to your first point, I agree with the time-lag argument because, if the universe is four dimensional then any time difference identifies two separate positions in a similar way to how any spatial difference in a 3 dimensional universe separates two different positions.  If two things are separated they cannot be the same thing.  I cannot see why this is unconvincing.

Now for the second point in which I said "Derrick's model would be false if subjective time and space bore no relationship to physical time and space. "  Derrick is postulating a simple difference in time between the retinal image and perception, with the relative positions of events in space being preserved. I pointed out that the argument would fail if we were deluded about the spatial arrangement of events in perception. I was not intending to help him, just to point out the circumstances in which his argument would be false, circumstances that I consider to be far-fetched in the extreme.

It was JoE who said: " "Relativity debars an actual universe because there is no such thing as simultaneous existence.", not me.  I do not agree with this.  In relativity each observer has a slice of 4 dimensional spacetime that contains simultaneous events.  I included the Wikibook reference to illustrate this point.

2010-09-06
The time-lag argument for the representational theory of perception
Reply to Nigel Thomas
NT: "There is no specific instant at which a visual experience happens, any more than there can be a specific instant at which we experience a melody."

Your argument that there "is no specific instant at which a visual experience happens" seems to propose impossible "instants" and then assigns these to any events that you also wish to be impossible. Our experience is extended in time, as you yourself seem to agree: "There is no specific instant at which a visual experience happens, any more than there can be a specific instant at which we experience a melody." But what you miss is that we have the whole bar of a tune in our experience, experience is extended in time, it is a whole succession of ordered events extended over about a second.  Your theory, which seems to be that there can only be instants therefore experience is impossible, is trumped by the observation that contains a bar of a tune.

You say that the discussion has "wandered far off topic" but it is the role of time in perception that is being considered in the comments prior to yours.  If the world were four dimensional (eg: if the generally accepted cosmology were true) then perception could indeed be extended in time so that there need not be a "specific instant at which we experience a melody".




2010-09-07
The time-lag argument for the representational theory of perception
Reply to Peter Cash
Dear Peter, When I said 'Relativity debars an actual universe because there is no such thing as simultaneous existence.' I was using actual in the scientific sense used by people like Henry Stapp (which is also the Whiteheadian sense). I had hoped the context would have been clear from my several previous posts but I appreciate that these ambiguities remain a major problem. We are all getting at cross purpose here. 
Einstein may be appalled, but he was well known for having trouble with such issues - hence his difficulty with QM. I take the view paraphrased by Douglas Bilodeau in J Consciousness Studies 1996: the so-called mysteries of QM are in fact a road map out of our ontological impasse. It is well worth reading. The JCS 2008 paper on my profile draws on this and gives the complete citation.



Jo

2010-09-09
The time-lag argument for the representational theory of perception
Sorry that I haven't been able to get involved in the recent discussions.

I've actually just finished a revised version of my article, which includes what I think is a stronger version of the argument:

1) Your vision of the scene in front of your eyes briefly receiving additional illumination from a camera flash is dependent on the light that is reflected off that scene travelling to your eyes and then being converted into electrical impulses, which must then travel to the visual areas of your brain, and then be processed, all of which takes 100 milliseconds, with the duration of a typical camera flash being 1 millisecond.

2) Therefore, this 1-millisecond-long additional illumination of the scene in front of your eyes doesn't actually occur in your vision of the scene until 100 milliseconds after it occurred in reality - as this diagram shows:



3) However, if this additional illumination of the scene in front of your eyes in reality occurs between the points in time T and T + 1 millisecond, then what actually occurs between T + 100 milliseconds and T + 101 milliseconds in your vision must be merely a subsequent mental representation of the scene receiving the additional illumination between T and T + 1 millisecond.

4) Also:

a) If your vision of the scene in front of your eyes during the camera flash is merely a mental representation of the scene receiving a particular overall level of illumination, then there is no reason why this shouldn't also be true of your vision of the scene before and after the flash, given that the only difference is that the scene is receiving a lower overall level of illumination.

b) Conversely, if your vision of the scene in front of your eyes before and after the camera flash were a direct experience of the scene receiving a particular overall level of illumination, then there is no reason why this wouldn't also be true of your vision of the scene during the flash, given that the only difference is that the scene is receiving a higher overall level of illumination.

5) Therefore, your vision must always be merely a mental representation of the scene in front of your eyes.

The article then address the most common objection to the time-lag argument:

You might be tempted to object to this argument as follows.

Your visual experience of the scene in front of your eyes of course necessarily involves information about the scene travelling to your brain, via your eyes, and then being processed, all of which of course takes a small amount of time. However, given that your visual experience is directly linked to the scene, via the perceptual process, the experience is still direct, even if it is necessarily a direct experience of the scene a fraction of a second ago. That is, what follows from the perceptual lag isn't that you cannot directly experience the world, but simply that you cannot directly experience the world without this very slight delay. The existence of the perceptual lag is only fatal for any naive theory of direct perception which requires that perception is instantaneous. Therefore, with respect to the 1-millisecond-long additional illumination of the scene in front of your eyes, although your visual experience of the event occurs between T + 100 milliseconds and T + 101 milliseconds, the experience is nevertheless a direct experience of the event occurring between T and T + 1 millisecond.

However, this objection misses the crucial point in the argument. If your visual experience of the event occurs between T + 100 milliseconds and T + 101 milliseconds, then this means that the 1-millisecond-long additional illumination of the scene in front of your eyes occurs between T + 100 milliseconds and T + 101 milliseconds in your vision of the scene. And this raises the question of what is actually occurring between T + 100 milliseconds and T + 101 milliseconds, given that the event itself occurred between T and T + 1 millisecond. And the only answer seems to be a subsequent mental representation of the scene receiving the additional illumination between T and T + 1 millisecond.

The full article is available here:

http://www.chainsofreason.org/this-is-a-simulation

Any comments would be gratefully received - I look forward to reading them after I return from a weekend break.

Annette: re your representation/re-presentation objection, perhaps we should just agree to disagree. You could always just substitute 'representation' with 'image'.

Best

Derrick

2010-09-11
The time-lag argument for the representational theory of perception
Derrick,

As you asked for comments, here are mine, for what they're worth.

1. The argument is logically deficient

Even if I grant, for the sake of argument, that there is some delay between the flash and the observer's perception of it, there seems to be a problem with your item 3. There, you say that it follows from the fact that there is a delay that "...what actually occurs between T + 100 milliseconds and T + 101 milliseconds in your vision must be merely a subsequent mental representation of the scene".

This claim really makes your further points trivial; if I buy item 3, then I've bought them all. Specifically, item 5 is merely an obvious generalization of the section of item 3 that I quoted above. The question then is: what argument do you present for your claim in item 3? I can find none, except the mere fact that there is a delay between the event and its perception. But this itself proves nothing; item 3 looks like a petitio to me.

Perhaps the proposition "if there is a delay between the event and my perception of it, then what I perceive can't be the real thing, but must be a mental representation of it" seems so obvious to you that you think no argument must really be presented for it. But if you do think this, then why pretend to present an argument at all?

By the way, Nigel Thomas raised a similar objection against the original form of your argument.

2. If we were subject to the "illusion" that we perceive the world, then your argument could not be stated.

If we have only the experience of the flash, and if this falls out to mean we cannot see the flash itself, then we can't know anything about the flash. In other words, your graphics should consist of only one row--the first. How could we determine when--or even if-- the "real" flash occurred, if we cannot--by virtue of your argument--know anything about it? The sequence of illustrations implies that we can fix both the flash and the observer's seeing of the flash in time, and measure the difference. I cannot imagine any scientific experiment that would establish such a temporal relationship.

You yourself raise what I take to be a version of this same argument in item 2) of your (full) paper: you attempt to demolish the assertion that representationalism is inherently unprovable. However, you do not seem to present a very forceful argument. You say of representationalism

"...such theories merely assume, rather than assert, that there exists a physical world and that the experiences that we call perceptions are indeed, somehow, experiences of that world."..."Therefore, contrary to this objection, the representative theory of perception merely asserts that if, as we assume, there exists a physical world and the experiences that we call perceptions are indeed experiences of that world, then what we directly experience perceptually isn't the physical world itself but merely a mental representation of it."
You seem to be opposing the objection to representationalism by saying that, according to representationalism, the existence of the "external" world is merely assumed. But that is precisely the objection! Far from refuting the claim of non-provability, you admit that it is true. Assumptions or assertions are not proofs, nor even arguments.

3. Delayed perception of events occurs frequently, but does not mean representationalism is true.

If you have ever watched a lightning storm or observed artillery fire, then you have perceived delayed perception. You see the lightning or the muzzle flash...then you hear the sound produced by the event. You hear thunder; you hear the detonation of the powder charge. To my knowledge, no one has ever argued that because of this delay, we hear only a representation of the thunder, or the detonation.

We notice these "delay" phenomena because the speed of light is much faster than the speed of sound. We compare the delay between the flash and bang. Yet we do not doubt that we are perceiving the same event through different senses. For that matter, we know that even light has a finite velocity, and our perception of the flash is also delayed--though there is no way we can observe this delay; not only is the delay infinitesimal, but there is no faster way to find out that any event has occurred, other than by light. As I stated in an earlier post, our visual perception would suffer this delay, even if we assumed vision was instantaneous. So if delay means that we do not see "directly", then we would still be, as you say, "...the victim of an extraordinary illusion"--even if the machinery of perception were itself instantaneous.

4. Smelling a Rat

Philosophers like to concentrate on vision, so I was gratified that you mentioned the sense of smell near the end of your full paper:
"It therefore takes a great conscious effort to remain aware as you walk down a street, for example, that all of what you are directly experiencing perceptually is merely a real-time, multi-sensory mental simulation of the world around you and your own body: the sight of the street scene around you...the smell of exhaust fumes..."
I simply must ask: do you smell the fumes of the past? Do you really smell fumes, or only a mental representation of fumes?

Suppose you smell gas in your rooms. Ordinarily, this would indicate some sort of emergency. However, because we are subject to deceptive illusions, perhaps the gas leak has stopped (assuming it existed at all). After all, how long does it take for odors to travel from their source to your nose? There's no point in declaring an emergency over some gas of the past. Best light a pipe to aid in the analysis of this philosophical puzzle.



2010-09-11
The time-lag argument for the representational theory of perception
Derrick, I see that you seem to have correlated "vision" with the N1 component of the Event Related Potential whereas almost all authors would put visual experience later than this.  Experience occurs at least as late as the P3 component and probably later (>300 ms post stimulus). Of course, reactions occur at around 250 ms, usually prior to conscious experience.

You have also included a bowl of flowers in the "scene" that is an optical image.  Bowls of flowers are not optical images. The only optical image in the whole scene/vision system is that produced on the retina by the lens system of the eye, an image that almost always differs between the two eyes.  Is the "scene" the retinal images or a spray of the light photons that were not absorbed going hither and thither between the object and the head or the empty space that is the principle component of an objective material object? If it is the retinal images there should be two of them in the diagram, if it is the photons the "scene" should be entirely white because a lens system is needed to separate the coloured components.

You also seem to have included a visual experience that is 1 ms long.  If you shut your eyes then open them for the shortest possible duration before shutting them again you will see that visual experience has a minimum duration of about 20-50 ms. Considerations such as the maximum firing rate of neurons, flicker fusion etc. lead to the same conclusion: that any single visual experience cannot occupy less than about 20 ms.  Notice that the frames of a moving cartoon are seamlessly sewn together if they are less than about 110 ms long and in disease states the minimum duration can be greatly extended leading to bizarre effects such as akinetopsia.

The representation of "vision" as a bowl of flowers is also suspect, we know that vision is processed as objects, a bit like the "sprites" in computer graphics  (this is most clear in states that occur in diseases such as simultanagnosia).  The visual bowl of flowers is a low definition object with potentially high definition components - "potentially" because the high definition requires attention (the addition of further objects).

The reason for a time-lag of about 500 ms between events and conscious experience is that it requires about 500 ms for the brain to create and coordinate the visual sprites and other sensory objects that compose that experience.  These internally created objects are not much like the objects that they represent and it is a wonder of the natural world that we can have a shadow on a retina and say "there is a shadow of a man on that white wall!". 



2010-09-12
The time-lag argument for the representational theory of perception
Reply to Peter Cash
PC: "You hear thunder; you hear the detonation of the powder charge. To my knowledge, no one has ever argued that because of this delay, we hear only a representation of the thunder, or the detonation."

I am glad you raised this point.  It is this idea that a machine or person who responds to a signal is responding directly to the cause of the signal that lies behind some interpretations of perception that are mistakenly called "direct realism".  The discussion of Direct Realism and Representationalism should tease out the three main states that might compose perception:

1. Events themselves
2. Signals derived from the events
3. Re-presentation or, in modern parlance, a virtual reality based on signals from the events.

Reid would maintain that the soul is united with events themselves, this is classical Direct Realism and corresponds to perception based on "1. Events themselves" . But PC is not addressing Reid's Direct Realism, he is introducing a more recent form of Realism in which signals derived from the events are also regarded as the events themselves.  I believe it is disingenuous to call signals "Direct Realism" and one of the more modern terms should be used (chose your own).   Despite this, PC is right to argue that the time-lag argument does not in itself justify re-presentation - it may only indicate a response to signals. However, the time-lag does argue against classical Direct Realism and Naive Realism.  As I said before, two events separated in time in a 4D universe must be different events.

According to the diagram, Derrick seems to be going for a full blown virtual reality interpretation of perception because he has a time-displaced image of a bowl of flowers as "vision".  His signals are re-presented (like mine are), we both have minds. However, I cannot agree with Derrick's "what we directly experience perceptually isn't the physical world itself but merely a mental representation of it." , I would have to say that experience is physical signals derived from physical events. There is no need for the "merely mental" and I cannot see why this needs to be introduced - the physical world could indeed make a mind from re-presented signals.

2010-09-13
The time-lag argument for the representational theory of perception
Thank you for your reply, J.W.K. I do want to set the record straight on one issue, though: I never mentioned "signals". I was using phrases like "hear the thunder" and "see the flash" in their ordinary language sense. My reply to Derrick is entirely (alas) negative. I am not proposing any theory of perception because I don't have such a theory.


2010-09-13
The time-lag argument for the representational theory of perception

To Derryck and Peter,

I hope, Derryck, that you will answer Peter's good question about whether we smell the fumes of the past, or indeed any fumes. Peter's point that the assumption that what we perceive represents something different, a world out there, neglects to acknowledge that if all we have are our perceptions, we could never know of any match or mismatch of them with it, is the same as Hume's point, in "Of scepticism with regard to the senses" against what he called "the "philosophers' theory" of double existence," that is our perceptions and the world they imperfectly represent. He points out that the only causes and effects, and resemblances, that we can know about are between perceived things, so to postulate causes of our perceptions which are insome respects different from them can never in the nature of things get any confirmation. He calls this  "a confusion of groundless and extraordinary opinions." It was not the time lag he thought made philosophers like Locke postulate material objects which differ in their qualities from what we seem to perceive, but the interruptedness of our perceptions of things, while  what is postulated is more lasting. He thinks such qualiities as philosophers  give such postulated mind-external things, such as position, shape, and motion, are taken from what we perceive, so they are really imagining themselves perceiving things as they really are, to compare their real qualities with what ordinary actual observers think they observe: the full panoply of secondary and primary qualities. They, imaginine themselves as super-perceivers whose perceptions get things right. But this is a fantasy.(Fumes would have no smell, for such super-perceivers, they would perceive only colorless particles in motion). So what was the moral? Not that our perceptions never deceive us about things, since in cases like the way a straight stick partially immersed in water, the way it looks can deceive us. But it is another sense, and vision of the stick out of water, which corrects the illusion. The moral Hume drew was that the only illusions we should think ourselves subject to, through perception, are the ones perception itself can correct, and that the only world we can know is the world as we sense it. All the information scientists get about brain processing, and the time it takes in vision and smell, comes from their observation of what their instruments tell them, so depends on trust in their senses. And the only cases of representation we should recognize are when someone can compare the representation with the represented, to see how well it represents.  But you surely know all this, Annette.    


2010-09-22
The time-lag argument for the representational theory of perception
Reply to Peter Cash
PC: "You hear thunder; you hear the detonation of the powder charge. To my knowledge, no one has ever argued that because of this delay, we hear only a representation of the thunder, or the detonation." and " I do want to set the record straight on one issue, though: I never mentioned "signals"

Are you suggesting that signals, such as sound waves in the case of the expanding gases after an electric discharge, do not allow you to " hear the detonation"?  Surely we can invoke basic physical ideas in this discussion or did you have some other idea about how you "hear thunder" or why signals cannot be assumed as intermediaries in our perception?

2010-09-22
The time-lag argument for the representational theory of perception
Annette: "And the only cases of representation we should recognize are when someone can compare the representation with the represented, to see how well it represents."

Nicely put.  I was making a similar point a couple of posts back when I noted that a real bowl of flowers is different from an image of a bowl of flowers and the mental image of a bowl of flowers is more like a "sprite" and not really like an image.

On Hume's implied problem of whether or not we can extrapolate from the state of signals to the physical state of the sources of these signals, obviously we can. Thats what we do all the time and it is the entire project of science.   So we can indeed know the relationships between the states of things but we cannot be the substance of things that are not our minds.

Even when I am dreaming my mind is a small part of the world, albeit in my brain, how could I doubt this or the possibility that this small part might be derived from and connected by signals to the whole?

Incidently, does anyone know how philosophers have got into such a mess when defining "physicalism"?  As a scientist I study the relations between states (forms), scientific physicalism is simply the observation that these states are interrelated.  On this definition the "mind" is the most pre-eminently physical geometric form that exists because it contains our observation, the "top level" of states that we interrelate.

2010-09-22
The time-lag argument for the representational theory of perception
This post contains replies to two earlier posts:

------------------------------------------

Hi John

The source of the 100 ms figure that I use for the visual lag is this paper:
Changizi, M., Hsieh, A., Nijhawan, R., Kanai, R.,&Shimojo, S., 2008, 'Perceiving the Present and a Systematization of Illusions', Cognitive Science: A Multidisciplinary Journal, 32:3, 459—503
which states:
Computation necessarily takes time and, because visual perceptions require complex computations, it is not surprising to learn that there is an appreciable latency—on the order of 100 msec—between the time of the retinal stimulus and the time of the elicited perception (Lennie, 1981; Maunsell &Gibson, 1992; Schmolesky et al., 1998).
Of course, whether the lag is 100 ms or 300 ms is not critical to the logic of the argument.

Re 'Bowls of flowers are not optical images':

There is no mention in the diagram, nor elsewhere in the argument, nor in the article as a whole, of optical images (I think the article doesn't anywhere even refer explicitly to the retinal image). The bottom row of the diagram depicts the scene at different points in time, whereas the top row depicts the content of the observer's vision of that scene at those points in time.

Re 'any single visual experience cannot occupy less than about 20 ms':

But people are indeed able to perceive the 1-ms-long illumination of a scene by a camera flash.

Re 'The representation of "vision" as a bowl of flowers is also suspect':

The purpose of the diagram is simply to illustrate that the 1-millisecond-long illumination of the scene occurs in the observer's vision 100 ms after it occurs in reality, and I feel that the diagram fulfils that purpose satisfactorily.

Best

Derrick

------------------------------------------

Hi Peter

Re 'The argument is logically deficient':

You're criticising an oversimplification of the argument that I present above. It is not true that the argument is simply saying: "if there is a delay between the event and my perception of it, then what I perceive can't be the real thing, but must be a mental representation of it". The argument indeed starts with the perceptual lag, and indeed ultimately concludes that one's vision is merely a mental representation of the scene in front of one's eyes, but there are also critical steps in between.

The argument is saying that, given the visual lag, the 1-ms-long illumination of the scene in front of one's eyes doesn't occur in one's vision until 100 ms after it occurred in reality. So if this event in reality occurs between the points in time T and T + 1 ms, then what is actually occurring between T + 100 ms and T + 101 ms in your vision? It can't be the event itself, because that occurred between the points in time T and T + 1 ms. The only possible answer seems to be a mental representation of that earlier event.

Also, I don't agree that steps 4 and 5 are trivial. Step 3 only concludes that the observer's vision of this specific 1-ms-long event is a mental representation of that event, whereas I am wanting to show that this is always true of vision. However obvious steps 4 and 5 may seem, it is still important to explicitly set-out the extrapolation.

Re: 'If we were subject to the "illusion" that we perceive the world, then your argument could not be stated':

The point that I make in the article is that perception is, by definition the process by which we experience the world (directly or indirectly), and so any theory of perception is simply saying that, if there exists a physical world and the experiences that we call perceptions are indeed, somehow, experiences of that world, then the nature of the perceptual process is X. That is, the problem of confirming that there is indeed a physical world, and that the experiences that we call perceptions are indeed, somehow, experiences of that world, isn't a problem for any theory of perception, because such theories do not assert that this is the case.

To answer your specific points about this:

- 'your graphics should consist of only one row'
- But the argument concerns the nature of perception, and any theory of perception starts from the premise that there exists a physical world, by definition.

- 'How could we determine when--or even if-- the "real" flash occurred, if we cannot--by virtue of your argument--know anything about it? The sequence of illustrations implies that we can fix both the flash and the observer's seeing of the flash in time, and measure the difference'
- There is no need to determine when, or if, the flash occurred, or when the observer experiences the flash, because it's just a thought experiment.
- 'Far from refuting the claim of non-provability, you admit that it is true.'
- I'm saying that the representative theory of perception, by definition, merely assumes, rather than asserts, that there is indeed a physical world and the experiences that we call perceptions are indeed, somehow, experiences of that world. So it isn't the job of the theory to prove that that these assumptions are true.
Re 'Delayed perception of events occurs frequently, but does not mean representationalism is true':

You write:
To my knowledge, no one has ever argued that because of this delay, we hear only a representation of the thunder, or the detonation.
First, the time-lag argument refers specifically to the delay in our perception of the world via a particular sense, not the differences in these delays for each of the senses.

Second, even aside from the previous point, a lack of support for a particular position is not a suitable reason for believing that that position is false.

You write:
Yet we do not doubt that we are perceiving the same event through different senses.
But the representative theory of perception doesn't claim otherwise.

You write:
For that matter, we know that even light has a finite velocity, and our perception of the flash is also delayed--though there is no way we can observe this delay; not only is the delay infinitesimal, but there is no faster way to find out that any event has occurred, other than by light. As I stated in an earlier post, our visual perception would suffer this delay, even if we assumed vision was instantaneous. So if delay means that we do not see "directly", then we would still be, as you say, "...the victim of an extraordinary illusion"--even if the machinery of perception were itself instantaneous
I don't see how this challenges the logic of the argument (perhaps it's not supposed to).

Re 'Smelling a Rat':

You write:
I simply must ask: do you smell the fumes of the past?
I smell the fumes that existed in my nasal channels a fraction of a second ago - and which will of course still exist in my nasal channels in the present instant, given that such fumes won't have moved significantly in that time.
Do you really smell fumes, or only a mental representation of fumes?
I smell fumes, by experiencing a mental representation of them. :-)
Suppose you smell gas in your rooms. Ordinarily, this would indicate some sort of emergency. However, because we are subject to deceptive illusions, perhaps the gas leak has stopped (assuming it existed at all). After all, how long does it take for odors to travel from their source to your nose? There's no point in declaring an emergency over some gas of the past. Best light a pipe to aid in the analysis of this philosophical puzzle.
We are evidently subject to 'deceptive illusions' whether perception is direct or indirect. Also, such a person would only react in that way if they were certain that a) the gas leak as stopped, and b) the gas that did leak has now dispersed, and I don't see why their knowledge of the tiny lag in their perceptions would lead them to draw these conclusions.

Best

Derrick

(No time to respond to the other posts today.)

2010-09-22
The time-lag argument for the representational theory of perception
Hi Annette

I follow what you say, but please see my reply to Peter on this point (which I posted after your last post).

Also, this is an objection to the representative theory of perception, whereas I'm really more interested in this thread in the time-lag argument. Which step, or steps, in my most recent formulation would you say is flawed?

Best

Derrick

2010-09-22
The time-lag argument for the representational theory of perception
Perhaps the logic of this formulation of the time-lag argument is clearer if I add a step between steps 2 and 3:

1) Your vision of the scene in front of your eyes briefly receiving additional illumination from a camera flash is dependent on the light that is reflected off that scene travelling to your eyes and then being converted into electrical impulses, which must then travel to the visual areas of your brain, and then be processed, all of which takes 100 ms, with the duration of a typical camera flash being 1 ms.

2) Therefore, if this additional illumination of the scene in front of your eyes occurs between the points in time T and T + 1 ms, then it won't occur in your vision of the scene until 100 ms later, between T + 100 ms and T + 101 ms.

3) However, if this event in reality occurs between T and T + 1 ms, then it can't itself also occur between T + 100 ms and T + 101 ms - and even if it did, it wouldn't occur in your vision for a further 100 ms.

4) Therefore, what actually occurs between T + 100 ms and T + 101 ms in your vision must be merely a subsequent mental representation of the scene receiving the additional illumination between T and T + 1 ms.

5) Also:

    a) If your vision of the scene in front of your eyes during the camera flash is merely a mental representation of the scene receiving a particular overall level of illumination, then there is no reason why this shouldn't also be true of your vision of the scene before and after the flash, given that the only difference is that the scene is receiving a lower overall level of illumination.

    b) Conversely, if your vision of the scene in front of your eyes before and after the camera flash were a direct experience of the scene receiving a particular overall level of illumination, then there is no reason why this wouldn't also be true of your vision of the scene during the flash, given that the only difference is that the scene is receiving a higher overall level of illumination.

6) Therefore, your vision must always be merely a mental representation of the scene in front of your eyes.



2010-09-23
The time-lag argument for the representational theory of perception
I've added yet another step - both of the two recently added steps are in bold:
1) Your vision of the scene in front of your eyes briefly receiving additional illumination from a camera flash is dependent on the light that is reflected off that scene travelling to your eyes and then being converted into electrical impulses, which must then travel to the visual areas of your brain and be processed, all of which takes 100 ms, with the duration of a typical camera flash being 1 ms.

2) Therefore, if this additional illumination of the scene in front of your eyes occurs between the points in time T and T + 1 ms, then it won't occur in your vision of the scene until 100 ms later, between T + 100 ms and T + 101 ms.

3) However, a specific event can't occur twice, by definition.

4) Therefore, if this additional illumination of the scene in front of your eyes in reality occurs between T and T + 1 ms, then it can't itself also occur between T + 100 ms and T + 101 ms - and even if it did, it wouldn't occur in your vision of the scene for a further 100 ms.


5) Therefore, what actually occurs between T + 100 ms and T + 101 ms in your vision of the scene must be merely a subsequent mental representation of the scene receiving the additional illumination between T and T + 1 ms.

6) Also:

  a) If your vision of the scene in front of your eyes during the camera flash is merely a mental representation of the scene receiving a particular overall level of illumination, then there is no reason why this shouldn't also be true of your vision of the scene before and after the flash, given that the only difference is that the scene is receiving a lower overall level of illumination.

 b) Conversely, if your vision of the scene in front of your eyes before and after the camera flash were a direct experience of the scene receiving a particular overall level of illumination, then there is no reason why this wouldn't also be true of your vision of the scene during the flash, given that the only difference is that the scene is receiving a higher overall level of illumination.

7) Therefore, your vision must always be merely a mental representation of the scene in front of your eyes.
... (expand)

2010-09-25
The time-lag argument for the representational theory of perception
You may think I am splitting hairs by concentrating on the actual events between a flash and perception but the reason I am focusing on the actual events is that I believe your version of the Time Lag Argument contains an assumption of Direct Realism that undermines the argument from the outset.  This assumption arises because by showing two images of bowls of flowers you are implying that there is in fact an image of a bowl of flowers, like the image in our perception, that is illuminated by the flash.  There is no such image out there.

Suppose the flash illuminated a photo of a bowl of flowers, or better still, a black dot. Is the black dot like my perception containing the dot? The dot is a set of pigment crystals on a surface. If I approach the dot from the side it is a fiftieth of a millimetre high and the instrument used to make this measurement only touches one crystal at the top and one at the bottom of the dot.  If we use a million instruments to locate every crystal on the flat surface of the dot we get a million signals in parallel.  Nowhere do we get a "view" containing a dot like this dot "." that occurs in my perception. A perception containing a dot is a geometrical form involving a projective geometry whereas a dot in the world is a collection of individual events arranged in space and time. The assumption that the physical dot, or your physical bowl of flowers, is like my view containing these things is an assumption of direct perception.

Perhaps the reason you have shown the flowers in the world as if they were already "perceived" is to hint at the way a Direct Realist might imagine the scene, a better hint might be to show a picture of a person with some sort of magic eye in the middle of their forehead who directly perceives the flowers during a flash. It would then be possible to ask the Direct Realist to explain how their magic eye creates the projective geometry of the view containing the flowers.

(Note: the paper you quoted by Changizi et al uses experiments by Schmolesky et al and Maunsell&Gibson on macaques to identify the 100 ms phase of visual processing. These experiments have little to do with conscious visual perception which probably occurs after the P3 phase in humans (>300 ms). Humans are usually required for these experiments because they can provide evidence for when they have conscious perceptual content.)



2010-09-25
The time-lag argument for the representational theory of perception
Derrick, you need to say what makes something " mere mental representation." Is everything mental a representation? Is there any way we can find out if it represents accurately or misrepresents? Does you argument show our vision to be a misrepresentation, since it presents as present what is really just past?  Annette Baier.

2010-09-26
The time-lag argument for the representational theory of perception
I would reword your points thus:

1. I would replace "scene", (a scene is a mental representation). The retinal image containing photons reflected from objects in front of your eyes receives additional illumination during a flash. The photons cause electrical impulses that create successive waves of activation of the visual cortex at periods from about 10 ms onwards, relatively peaking at 100ms and 300ms.

2. I would be accurate about the cortical ERP: The additional illumination gives rise to an event related potential in the visual cortex from about 10ms to 700ms post flash.

3.  A specific event cannot occur twice in a four dimensional spacetime (it may well be able to in 3D or nD). In fact this is the entire argument about time-lags: the universe is 4D therefore the same event cannot be at two separate times.

4. See 3

5. See 3. I do not agree that we can blithely use the term "mental representation" in the context of Event Related Potentials.  A mental representation containing a flash is not a set of electrical pulses occurring over about 700 ms, it must be something else.

What do you mean by "mental representation"?  I would describe it as a projective geometry formed by the concurrent and simultaneous events in my experience.  Is that what you meant?



2010-10-02
The time-lag argument for the representational theory of perception
Hi John

Re your post 'You may think I am splitting hairs ...':

The diagram isn't actually part of the argument, but is simply an illustration of one of the steps in the argument. That is, the logic of the argument doesn't rely on the diagram, and so even if the diagram were problematic, this wouldn't have any implications of the logic of the argument.

With respect to your objection to the diagram, whether one believes that vision is a direct or indirect experience of the scene in front of one's eyes, one would agree that one's vision has content, and the diagram is simply a depiction of that content. That is, the diagram is neutral with respect to whether one's vision is direct or indirect.

However, I've now removed the diagram from the article as I think that the step in question probably doesn't require illustration, and was worried that the diagram interrupts the flow of the argument.

Re your post 'I would reword your points thus ...':

'a scene is a mental representation'
- a scene, in this context, is the area of the world in front of the observer's eyes.
'I do not agree that we can blithely use the term "mental representation" in the context of Event Related Potentials'
- the argument doesn't refer to ERPs, explicitly or implicitly, but to the lag between what is being perceived and the perceptual experience
'What do you mean by "mental representation"?'
- In the case of vision, I believe that what one directly experiences visually is not the scene in front of one's eyes, but merely a representation of it, and which is mental in nature - in the same way that a visual memory is a representation of a scene and is mental in nature. In the case of vision, the term 'mental image' can be used instead.

Best

Derrick



2010-10-02
The time-lag argument for the representational theory of perception
Below is the latest version of the argument. It would be very helpful to me, and I think it would also help keep the discussion focussed, if people with objections to the argument could express each of those objections along the lines of 'I think step X is problematic because Y'. Also, I'm really just interested here in people's thoughts on the below argument, rather than the representative theory of perception itself - this thread is already long enough!!!

1) Your vision of the scene in front of your eyes briefly receiving additional illumination from a camera flash is dependent on the light that is reflected off that scene travelling to your eyes and then being converted into electrical impulses, which must then travel to the visual areas of your brain and be processed, all of which takes 100 ms, with the duration of a typical camera flash being 1 ms.

2) Therefore, if the additional illumination of the scene in front of your eyes occurs between the points in time T and T + 1 ms, then it won't occur in your vision of the scene until 100 ms later, between T + 100 ms and T + 101 ms.

3) However, a specific event occurs solely between two specific points in time, and so can't itself also occur between two later points in time.

4) Therefore, if the additional illumination of the scene in front of your eyes in reality occurs between T and T + 1 ms, then it can't itself also occur between T + 100 ms and T + 101 ms - and even if it did, it wouldn't occur in your vision of the scene for a further 100 ms.

5) Therefore, what actually occurs between T + 100 ms and T + 101 ms in your vision of the scene must be merely a subsequent mental representation of the scene receiving the additional illumination between T and T + 1 ms.

6) Also:

    a) If your vision of the scene in front of your eyes during the camera flash is merely a mental representation of the scene receiving a particular overall level of illumination, then there is no reason why this shouldn't also be true of your vision of the scene before and after the flash, given that the only difference is that the scene is receiving a lower overall level of illumination.

    b) Conversely, if your vision of the scene in front of your eyes before and after the camera flash were a direct experience of the scene receiving a particular overall level of illumination, then there is no reason why this wouldn't also be true of your vision of the scene during the flash, given that the only difference is that the scene is receiving a higher overall level of illumination.

7) Therefore, your vision must always be merely a mental representation of the scene in front of your eyes.

Best

Derrick

2010-10-03
The time-lag argument for the representational theory of perception
The trouble is Derrick, that the way the argument is constructed does not matter. Your first and latest shots are equally good at making the point. The problem, if there is one, is the multiple meanings of words. If your readers make the Wittgensteinian mistake of trying to straightjacket words into jobs they should not do then however you formulate the idea they will claim it is wrong. 
As far as I can see the argument you need to counter is this: 
1. Things have qualitative properties, like colour or fragrance.
2. Either these qualitative properties of trees or fresh bread are communicated to us as they are, through signal pathways in space and nerves (that will of course take time) or there is some sort of rely station where a 'representation' is set up in the brain that has qualitative properties that are in some way analogous to those of the tree or bread. The subject then 'sees' the representation.
3. Representational 'qualitative properties by analogy' or 'sense data' would not be available as colour or fragrance to a neurosurgeon inspecting the brain but would to the person with the brain.
4. Postulation of sense data is unparsimonious and unsupported by evidence so is to be rejected. 
5. Therefore, qualitative properties should be considered available 'directly' rather than via local surrogate sense data in the brain.

The impasse between your view and that of the direct realists is built on the category mistake that things have qualitative properties. This is a false intuition that science had already rumbled in the seventeenth century. Inasmuch as there are things at all they are dynamic entities that only have dispositional properties. Qualitative features can belong only to interactions and exist only for the protoganist in the interaction from whose viewpoint the description of the interaction is being made - somewhere deep inside a brain. Thus there have to be internal sensory data but they were never going to be qualitative properties in the philosophers' sense.

Best wishes
Jo E

2010-10-03
The time-lag argument for the representational theory of perception
I think step 2 is problematic because it assumes the existence of something (an event?) here referred to as "your vision of the scene" that is taken to correspond both to some neural event (presumably the "processing" or the output of the processing mentioned in step 1) and to the conscious experience of seeing whatever is out there, and which is assumed to occur at some precisely definable (within milliseconds) time.

To assume that there is such an event is to assume a version of the indirect, representational theory of perception –  the theory that perceptual experiences can be identified with (or are caused by) specific inner states or events – and thus makes the argument as a whole question begging. The reasons you give for thinking that there is a time lag in visual perception (i.e., the finite time it will take to complete a physical causal chain between a visible event and its effect, a brain state corresponding to "your vision of the scene") are only relevant if visual perception is representational in this sense. There is a time lag in vision, if and only if vision is representational.

Non-representational theorists will (or, anyway, should) deny that visual perception consists in this sort of unidirectional chain of causes, with a well defined (and thus precisely timeable) terminus in the creation of some representational neural state. It follows from the fact that physical (including physiological) process take time, that perception takes time, but to accept that is not same thing as to accept that perception involves a "time lag," an interval between when the perceptual process begins (when the visible event occurs? when the light strikes the retina?) and when it completes (when the inner representation is achieved).

2010-10-11
The time-lag argument for the representational theory of perception
Hi Jo

I understand your objection, but you're objecting to the representative theory of perception itself, whereas I'm trying to keep this thread focussed on the time-lag argument for that theory.

That is, there are two ways to challenge a theory:

1) Challenge the theory with counter-arguments.
2) Identify flaws in any arguments used to support the theory.

My intended purpose of this thread is to solely discuss any flaws that people believe exist in the time-lag argument - and specifically the formulation of the argument that I'm presenting here.

That's why I'm suggesting that people express any objections to the argument along the lines of 'I think step X is problematic because Y'.

That is, if the representative theory of perception is indeed false - for whatever reason - then this means that the time-lag argument must of course be flawed.

But what are those flaws?

That is, which steps do you think are problematic, and why?

Best

Derrick

2010-10-11
The time-lag argument for the representational theory of perception
Might I suggest replacing the experimental setup with a fast flash a kilometre from the eye and a fast optical gate 500 metres from the eye.  The gate would shut the moment the flash had passed so isolating the light in the gap between the gate and the retina.  It is then certain that vision occurs after the event in the world.  The interpretation is then a matter of cosmology - in a 4D world the vision must be a separate event from the original flash. We can then dispense with flowers, scenes and views.

2010-10-11
The time-lag argument for the representational theory of perception
Derrick, there still seem to be two big problems with the argument, the first is that you have not demonstrated that the visual experience is contemporary with electrical events in the brain (as Nigel Thomas and I mentioned) and the second is that you have used the word "scene" to describe the physical flowers.

The two problems come from two assumptions.  The first assumption is that vision derives from neural activity and is hence a representation in the brain and the second assumption is that the "scene" is like the vision of the flowers.  I agree with the first assumption but I cannot see how your argument justifies it.  I do not agree at all with the second assumption, physical objects are not like vision, they are not like views containing qualia related to these objects.   

The most important difference between a vision and its object is that a view or "scene" is a geometrical entity with events distributed in space and time and includes an apparent viewing point.  Just look, you can reach out to pick up the flowers, there is a radial space in vision that is not a property of the flowers.  If you accept this radial space then the apparent size of the flowers is an angular displacement relative to the apparent viewing point.  This "view" containing "flowers" is scarcely like physical flowers at all. It could be claimed that the view is like the passage of light through the geometrical optics of the eye but this does not bear close inspection, the only images in this system are on the retinas and these are not like the view that occurs in vision (you can't reach out into an image and there is no apparent viewing point).  If physical objects are not like vision but only related to vision there is no need for a time-lag argument.


2010-10-11
The time-lag argument for the representational theory of perception
Reply to Nigel Thomas
Hi Nigel

I don't follow why you think that step 2 is based on the implicit premise that vision is representational. It simply states that an event in the scene in front of the observer doesn't occur in the observer's vision until the information about that event has reached the observer's brain, via their eyes, and then been processed, which takes 100 ms.

You write:
There is a time lag in vision, if and only if vision is representational.
I would say that there is a time lag in vision if and only if vision is dependent on a time-consuming process.

I also don't follow this bit:
perception takes time, but to accept that is not same thing as to accept that perception involves a "time lag,"
If 'perception takes time', then one's perception of an event can't start until after that event as started, which constitutes a lag.

You seem to deny that 'visual perception consists in this sort of unidirectional chain of causes', but the visual process is indeed unidirectional: Each stage in the visual process is essential to one's vision - you would have no vision if your eyes were removed, or if instead your optic nerves were removed, or the visual areas of your brain were removed. But the processing in the brain obviously can't occur until the information that is to be processed has reached the brain from the eyes via the optic nerves, and the information obviously can't travel along the optic nerves from the eyes to the brain until the information has been extracted by the eyes from the light striking the retinas, and the light obviously cannot strike the retinas until it has travelled from the scene to the retinas. So each stage in the visual process does indeed only occur in a specific order. And if all stages in that process are essential, then visual perception only occurs once that entire process has been completed.

Best

Derrick

2010-10-11
The time-lag argument for the representational theory of perception
Derrick, you need a premise saying that for what we see to be anything other than a representation, what we see must be present, not just past. But if simultaneity of seeing and seen is impossible, given how vision works, then nothing would count as direct nonrepresentation-mediated access, so that premise looks very hard to defend. I know this pushes the issue back to representative perception, but if you insist on phrasing your conclusion by referring to a representation, you cannot avoid saying what makes something a mere representation. Or so it seems to me. Annette  Baier..  

2010-10-12
The time-lag argument for the representational theory of perception
Derrick Farnell: "an event in the scene in front of the observer doesn't occur in the observer's vision until the information about that event has reached the observer's brain"

That is a nice, succinct statement of the representational theory of vision, and it would be a representational theory even if (per impossible) all the physical events in the causal chain happened instantaneously. The "information in the brain" that you talk about, that you take to give rise to (or, perhaps, be identical with) "the observer's vision" is the relevant representation. I can understand why you might find it hard to imagine that perception might be otherwise - after all, nearly all (but not quite all*) accounts of perception, scientific and philosophical, ever since Descartes (indeed, perhaps ever since Alhacen) have been of this form - but to point out (quite correctly) that if perception is like this, then (given the fact that physical processes take time) it will involve a time lag is not to prove, or even to provide any new reason to believe, that perception is like this.
*[Examples of people who have held alternative views (apart from myself) include Noë, O'Regan, Gibson, Neisser, the many roboticists who advocate "active vision" (e.g., Bajcsy, Ballard, Aliomonos)  and non-representational robotics (Brooks), and the "extramissionists" (including, Euclid, Ptolemy, Al-Kindi, and the stoics) who dominated visual theory in antiquity. You may not think any of them are right, but these are your opposition, not people who already think of perception, like you do, within a representationalist framework.]

Derrick Farnell: "if all stages in that process are essential, then visual perception only occurs once that entire process has been completed."

Only if you are assuming that what you here refer to as "visual perception" (by which I think you must mean a visual experience) is an end product of the entire process, i.e. a representation in the brain. Suppose, however, that visual perception (or even visual experience) is identical with (or supervenient upon, or whatever) the whole process. Then it is true to say that visual perception takes time (and that it depends on all the physical events and structures that you mention, and probably others too), but not true to say that involves a lag, because (on this view) the perception is not something that occurs after (or when) the process completes, but is something that occurs while the process is going on, both the physical process and the "visual perception" that it constitutes being extended in time. For a car to move forward, the wheels must turn, the pistons must move up and down, and all sorts of other physical processes must happen in the engine, but the car does not move after all those processes have happened, it moves while they are happening.

I do not say that that is the only other way (apart from yours) that one might look at the matter, but it is certainly an alternative way, that is not obviously incoherent. If you think it is false then you need to show that, and it is no good to say it is false because it is inconsistent with the representational theory of perception, because that would be, again, to beg the question.

2010-10-17
The time-lag argument for the representational theory of perception
Derrick to Nigel: "I don't follow why you think that step 2 is based on the implicit premise that vision is representational"

I also raised the point that Derrick's argument simply assumes that visual experience is consequent upon brain activity.  Suppose, to be a devil's advocate, I were to maintain that visual experience is directly events in the world beyond the body and what we measure in the brain is further processing of  these events. The time lag arguments are then a non-sequitur. Yes, there might be time lags in the brain but these would have nothing to do with experience.

If I were a Direct Realist I would agree that neural time-lags are consistent with a form of Representationalism but they are also consistent with Direct Realism, after all, the body must process the light to react to it.  I am not a Direct Realist which is why I proposed you might use an optical gate to make it clear that there is a non-neural time lag in your argument. If the flash of light is entirely isolated from its source when it is seen then it is difficult to argue that it is the source rather than a signal from the source that enters visual experience.


2010-10-17
The time-lag argument for the representational theory of perception
Hi all

Thanks very much for your most recent posts. I've now come-up with what I think is a much better a way of wording the argument, and hopefully you'll think that it removes at least some of your objections:

It's important at this point to define two closely related, and often confused, terms: 'field of vision' and 'visual field'. The field of vision is the input to the visual process - the area of the world that you are experiencing visually - whereas the visual field is the output of the visual process - your visual experience. Indeed, one's visual field doesn't always match the field of vision, as in the case of visual field defects, or when an hallucinated object appears in one's visual field.

So, given the 0.1 s delay in visual perception, your visual field lags behind visible events in the field of vision by 0.1 s.

     Argument:

1) Your vision of the scene in front of your eyes briefly receiving additional illumination from a camera flash is dependent on the light that is reflected off that scene travelling to your eyes and then being converted into electrical impulses, which must then travel to the visual areas of your brain and be processed, all of which takes 100 ms, with the duration of a typical camera flash being 1 ms.

2) Therefore, if the additional illumination of the field of vision occurs between the points in time T and T + 1 ms, then it won't occur in your visual field until 100 ms later, between T + 100 ms and T + 101 ms - as this diagram shows:


3) However, a specific event occurs solely between two specific points in time, and so can't itself also occur between two later points in time.

4) Therefore, if the additional illumination of the field of vision in reality occurs between T and T + 1 ms, then it can't itself also occur between T + 100 ms and T + 101 ms - and even if it could, it wouldn't then occur in your visual field for a further 100 ms.

5) Therefore, what actually occurs in your visual field between T + 100 ms and T + 101 ms must be merely a subsequent mental representation of the field of vision receiving the additional illumination between T and T + 1 ms.

6) Also:

   a) If what you directly experience visually when you see the 1-ms-long additional illumination of the scene in front of your eyes is merely a mental representation of the scene receiving a particular overall level of illumination, then there is no reason why this shouldn't also be true of your visual experience of the scene before and after the flash, given that the only difference is that the scene is receiving a lower overall level of illumination.

   b) Conversely, if what you directly experience visually when seeing the scene before and after the camera flash is a direct experience of the scene receiving a particular overall level of illumination, then there is no reason why this wouldn't also be true of your visual experience during the flash, given that the only difference is that the scene is receiving a higher overall level of illumination.

7) Therefore, what you directly experience visually must always be merely a mental representation of the scene in front of your eyes.

You might be tempted to object to this argument as follows.

Your visual experience of the scene in front of your eyes of course necessarily involves information about that scene travelling to your brain, via your eyes, and then being processed, all of which of course takes a small amount of time. However, given that your visual experience is therefore directly linked to the scene, via the perceptual process, the experience is still direct, even if it is necessarily a direct experience of the scene a fraction of a second ago. That is, what follows from the perceptual lag isn't that you cannot directly experience the world, but simply that you cannot directly experience the world without this very slight delay. The existence of the perceptual lag is only fatal for any naive theory of direct perception which requires that perception is instantaneous. Therefore, with respect to the 1-ms-long additional illumination of the scene in front of your eyes, what actually occurs between T + 100 ms and T + 101 ms is simply your direct visual experience of this event occurring between T and T + 1 ms, rather than a problematic second occurrence of the event.

However, to say that you visually experience a 1-ms-long additional illumination of the scene in front of your eyes - of the field of vision - is to say that this event occurs at some point in time in your visual field. But, given the visual lag, if the event occurs in the field of vision between T and T + 1 ms, then it must occur in your visual field between T + 100 ms and T + 101 ms - as stated in step 2, and shown in the diagram. For example, imagine that you were somehow able to make a high-speed video recording of your visual field before, during and after your visual experience of the event. The flash is connected to the recording equipment so that the firing of the flash starts a timer which is superimposed onto a corner of the recorded image, and which counts in milliseconds. If you were to then play the video back in slow motion, you would see the event occurring in the video - your visual field - when the timer reaches 100 ms.

Therefore, what occurs between T + 100 ms and T + 101 ms is indeed a problematic second occurrence of the event.


As I said above, it would help me if you could explicitly state which step, or steps, in the argument you think are flawed - and why.

Full article: http://www.chainsofreason.org/this-is-a-simulation

Best

Derrick


2010-10-17
The time-lag argument for the representational theory of perception
Annette: Where do you believe this extra premise should be inserted, and why do you think the following premise doesn't otherwise work?

Nigel:

Re your comments on the first quote from me. As I said to Peter earlier:
You're criticising an oversimplification of the argument that I present above. It is not true that the argument is simply saying: "if there is a delay between the event and my perception of it, then what I perceive can't be the real thing, but must be a mental representation of it". The argument indeed starts with the perceptual lag, and indeed ultimately concludes that one's vision is merely a mental representation of the scene in front of one's eyes, but there are also critical steps in between.
Which steps in the argument do you think are flawed, and why?

Re your comments on the second quote from me. I wasn't just saying that all of the stages in the visual process are critical, but also that each stage cannot begin until the previous one has finished (e.g. the brain can't process visual information until that information has travelled from the eye to the brain). Therefore, given these two facts together, conscious visual perception of a stimulus doesn't occur until the entire process has completed. Re the car, the wheels indeed won't move until the entire causal chain has completed, but the chain is so quick that you won't notice its duration. The movement in the engine that is occurring simultaneously with the movement of the wheels didn't cause that wheel movement at that point in time, but will be responsible for the wheel movement at some point in the immediate future.

2010-10-20
The time-lag argument for the representational theory of perception
Although I haven't read this thread in its entirety, I get the sense that direct realist arguments are being strawmaned here. I recently wrote a blog post on exactly this subject, which I thought would be relevant here. I apologize if this violates forum etiquette but since my post is so relevant I am just going to post it here rather than summarizing my argument. The basic gist of my argument is that anatomical facts about "time-lags" will not settle the psychological question of indirect vs direct perception. To think otherwise is to assume that direct realists somehow deny that perception of the environment is mediated by the brain, which is absurd. Moreover, sophisticated direct realists will never say that an organism "perceives the world directly". Rather, the direct realist in the Gibsonian tradition will say that direct perception involves the direct perception of an affordance, which is an objective property of the environment. I cash this out below.

-----------------------------------

The debate between direct perception and indirect perception has been going on for quite some time. Indirect theorists often point out that anatomical facts such as afferent and efferent nerves undoubtedly indicate that perception is indirect because simple anatomy tells us that the stimulus has to first be transduced and shuttled through the various nervous channels before being cognitively processed and transformed into a genuine “perception”. But if we are going to make  theoretical progress , we must realize that anatomical facts will not settle this debate.

Direct theorists have never denied that the perceptual process can be  artificially decomposed into anatomical facts. Both sides can agree that a stimulus must pass through various nervous channels; it does not get a free pass straight to the mind, the stimulus must be mediated by the brain. But what is the nature of this stimulus? Theorists on both sides rarely make their definition of stimulus explicit. It is assumed that everyone knows what everyone else means when they talk about the perceptual stimulus. This is a mistake. The issue is much more complicated that it first seems.

Indirect theorists often start their psychologizing from the perspective of neuroanatomy and physiology. They first zoom in on the retina very close and attempt to build a psychological model of vision beginning with meaningless physical intensities as proposed in the physical sciences. It is usually assumed that any psychological theory of visual perception must explain how the brain interprets this raw physical data (“sense-data”) and converts it into a meaningful percept. Sometimes this transition from meaninglessness to meaning is talked about in terms of the generation of true beliefs or true representations. But the essential question is always, How do you go from raw physical data to meaningful perception when the meaningless physical intensities are highly ambiguous and often irrelevant?

Direct theorists also make a distinction between meaningless sensation and meaningful perception, but reject the idea that the perceptual stimulus is meaningless. The classic example is the Ganzfeld experiments. 20th century vision scientists discovered that if the physical stimulus is undifferentiated, meaningful perception fails to occur even though the visual system is being stimulated. Direct theorists thus make a distinction between sensory stimulation and stimulus information. Imagine standing in an open field on a bright, cloudless day. When you orient yourself such that the sky fills your entire visual field, your sensory receptors are being stimulated but there is no meaningful perception occurring because there is no meaningful information to be differentiated from the stimulus because the stimulus is entirely homogeneous and undifferentiated. In other words, the undifferentiated sky contains no stimulus information, although it is stimulating.

Now here is the important point. The facts associated with sensory stimulation are facts of an anatomical or physiological nature. But they are not psychological facts. We cannot decide between an indirect theory and a direct theory on the basis of these physiological facts. We must focus on the perception of meaningful stimulus information.

Indirect theorists explain meaningful stimulus information with a mix of association psychology and computational representationalism. Meaningful percepts are generated whenever the cognitive system makes certain inferences (associations) from the raw stimulus with the premises either innate or learned in experience. Classic cognitive science talks about explicit symbol systems and generalized intelligence, but modern computational stories have become more and more complex. But almost all of them assume that the quintessential problem for visual perception is turning meaningless data into meaningful perceptions. This is nothing less than the mind/body problem applied to visual science.

But direct theorists reject this approach altogether. Although direct theorists admit that stimulation is sometimes meaningless (such as when we are looking at the undifferentiated sky or in a snow storm), they emphatically insist that, under normal circumstances, the immediate terrestrial environment is differentiated and highly organized. The differential structure of the ambient energy fields surrounding an organism is informationally rich. But not in the Shannon cybernetics sense of information (which was never meant to be a psychological theory). The environment is informationally rich insofar as it contains information specific to affordances (opportunities for behavior)

Direct theorists claim that the ambient energy fields are filled to the brim with redundant information specific to affordance properties. Affordance properties are real, objective facts about the environment.On my view, affordances are real properties of the environment that persist through time. The fact that the ground will afford my locomotion upon it is a fact that is independent of whether I actually utilize the ground for the purpose of locomoting. But it would be a mistake to think that this fact about the world is a molecular or local fact. The fact that the ground surface supports locomotion is a molar fact.

If we look at the ground on the timescale of millions of years, the ground is but a ceaseless flow of energy, ever shifting and changing. On the ecological timescale, however, the ground is stratified, ossified, and stabilized. And since our perceptual systems are tuned into this ecological scale, we do not perceive the molecular flux of the ambient energy fields. The ground is perceived as a continuous rigid surface with the property of “supportability”. This is an affordance-property. The detection of such properties by the nervous system is highly useful. We can expect that evolved systems would be optimally tuned to detect these properties because they are facts about the environment most relevant to survival.

We can cash this out psychologically in terms of how the perceptual systems seek information specific to these affordance properties. The affordance-property of supportability is a persisting fact about the ground surface. Under normal evolutionary conditions, the perception of this affordance-property is done so as to coordinate the motor system  and enable successful navigation through the terrestrial environment.

Take Herbert Simon’s example of an ant crawling along the beach surface. On first blush, its locomotive pathway seems highly complex and difficult to explain.The indirect theorist would attempt to explain its locomotive patterns in terms of internal control wherein the motor sysem is totally in charge of directing where to place each leg.  However, the direct theorist would explain its locomotive patterns by saying that the ant is merely following the contours of the sand. Rather than the ant controlling itself from within, the environment is guiding the ant. Put another way, the ant is using the affordance-properties of the beach to coordinate and regulate its behavior. The pathway looks complex only because the sand surface is complex, but the psychological control is actually quite simple.

On the neural level, we can say that there is a intrinsic flexibility and variability in the nervous system, otherwise the system would never be able to handle the complexity and novelty of the ever changing environment. However, the persisting affordance properties of the environment are sought out and detected so as to help coordinate motor behavior. Rather than the perceptual stimulus being a raw mechanical instruction or "input", the perceptual stimulus helps “select” or “trigger” useful patterns of neural activity from the intrinsic variability. Faced with the same tasks and problems over a developmental life cycle, certain patterns are going to be burnt in that help the animal cope with the environment. But it would be a mistake to decompose the task of action-coordination into purely internal neural circuity. The affordance theory recognizes how animals use both internal and external means of coordinating behavior. The neural system readily uses information specific to affordances to regulate behavior. This means that some behavior control is “external”. The problem then is not, How does the brain generate meaning from meaningless data? Rather, the problem is, How does the brain seek out meaningful information and then use it to regulate and coordinate its autonomous behavior?



2010-10-20
The time-lag argument for the representational theory of perception
Any self respecting Direct Realist would say of your argument: "fine, you have given a description of your representational theory of perception but this does not affect my view at all.  I believe that I directly experience events in the world, backwardly referred in time or instantaneously one with the events.  All this stuff in the brain is just information processing so that the right words come out to describe my experience." 

I cannot see how the time lag in the way you have described it proves representationalism.  The argument needs a clear demonstration that visual experience is indeed the same as some secondary event that can be timed.  What event that can be timed are you proposing as the substrate of visual experience and how do you know that it is indeed the substrate of visual experience?

2010-10-20
The time-lag argument for the representational theory of perception
Derrick, you need to say, at some point in your argument, best just before your conclusion, why the repeat event, in the case of vision, is also a re-presentation. The earlier occurrence of that event was not presented to the mind at all, so only with vision is it before a mind. I am here, I think, agreeing with Gary Williams, whose blog I thought spot on. Annette B. 

2010-10-21
The time-lag argument for the representational theory of perception
Reply to Gary Williams
GW, thank you for a good description of modern Direct Realism.  I am not sure that the modern idea actually differs from Reid's ideas, both Gibson and Reid are implying that there is a substrate in the world that affords the framework for our experience, or, in other words, experience supervenes on the outside world without supervening on neural events. In physical terms they are both proposing that the world outside the brain is the substrate of experience (see my previous post). 

The supervenience arguments of Direct Realism and Indirect Realism and, for that matter, Dualism all get us nowhere because the real problem is how the substrate can form our experience no matter where or what it is.  This mapping of substrate to experience is a cosmological problem because it is the problem of how a set of events can have the same form (eg: spacetime geometry) as experience.  Clearly the instantaneous set of nerve impulses in the brain do not have the same form as experience, just look around you, and also the instantaneous set of particles in the world do not have this form.  Indeed, even the Dualists have this problem of linking the form of a substrate to the form of experience.

"Affordance" seems to be an attempt at introducing time into our description and affordance could be applied to the general pattern of neural events that are triggered by the outside world in the same way as it is applied to the outside world itself.  Perhaps we could take on board the cosmological ideas of the last century and introduce time as a geometrical entity instead of an ill defined "affordance".

2010-10-21
The time-lag argument for the representational theory of perception
Gary: Thanks for your blog post - I've quickly read through it, and will study it in more detail shortly. However:

John, Gary and everyone else:

Ultimately, if the argument fails to demonstrate the truth of the representative theory of perception, then there must be at least one step in the argument that is flawed.

So which steps in the argument are flawed, and why?

This specific question is the sole subject of this thread (although the argument that it relates to has been evolving - the latest formulation was posted on 17 Oct).

For example:

With respect to step 2, do you disagree that the event occurs in the observer's visual field between T + 100 ms and T + 101 ms (bearing in mind the distinction made in my 17 Oct post between field of vision and visual field)?

If you don't disagree with this, do you disagree that, as stated in step 4, this occurrence in your visual field cannot literally be the event itself, given that the event in reality occurred between T and T + 1 ms, and also given that, as stated in step 3, a specific event occurs solely between two specific points in time, and so can't itself also occur between two later points in time?

2010-10-24
The time-lag argument for the representational theory of perception
Derrick, I apologize for not responding to your reply to my posting until now. Regrettably, there is seldom time for philosophy in my life.

In your reply, you say:
But the argument concerns the nature of perception, and any theory of perception starts from the premise that there exists a physical world, by definition.
You are correct, I have misunderstood you. I now think that your version of the Time Lag Argument begins with an implicit premise that your audience is expected to take for granted: you think that we all start with some sort of theory of perception. This is likely true; my own belief that no theory of perception is required is probably not particularly popular. Therefore, your argument addresses all those philosophers who have indeed either adopted or formulated a theory of perception, and its purpose is to convince them that your particular favorite--representationalism--is the true variant, and all others are false.

I must, therefore, withdraw my main objection to your argument--that it is a petitio. For it now seems that if we start with "any theory of perception", then we must start with a given: that there are perceptions. And by definition, perceptions are of something, and that something is the object of perception. Thus, we have both the notions of perception and of the world right at the beginning, and we have got them legitimately, for we have a theory of perception, in which these two concepts are necessarily taken as givens. To put it in graphical terms, I must accept both your rows of pictures, they are allowed at the start. If we have a theory of perception.

I fear that I shan't get many plaudits in this--or any other philosophical forum--for revealing that I have failed to acquire a theory of perception; I might as well admit I don't have a theory of mind, am completely ignorant of matter...do I hear the ice cracking under my feet?

Returning (hastily) to your argument, Derrick, I am still troubled about it, even if I accept your implicit premise for the sake of argument. If I understand you correctly, I must put myself in the position of someone who has "a theory of perception", and examine whether it is valid--whether it leads me to admit that I must be a representationalist.

Toward that goal, I will pretend I am Bishop Berkeley. (Aim high, I always say!) I believe that my perceptions are ideas, and that the physical world does not exist--esse est percipi, and all that. True, God exists, and assures the continuity of the ideal world when even when nobody is watching, but the vase of flowers, that's strictly mind-stuff. As are my eyeballs, my retina, my optic nerves, and my brain. To an idealist, scientific measurements of nerve impulse transmissions would, presumably, be pretty silly--they have nothing to do with ideas, they have no connection with my perception of reality. So why should I accept that row of images you have labeled "Scene"? That stuff doesn't happen; just the "Vision" row refers to something real. As long as I'm a bishop, in any case.

Indeed, what do you say about Berkeley, Derrick? Did he have a "theory of perception" at all, according to your lights? If yes, then it would seem that such a theory does not automatically bring in the "world" and "perception" duality. If no...well, that seems rather a drastic thing to say about such a famous (if dead) philosopher.

Returning to my secular self, I have to wonder what my alternatives are, once I've accepted that there is a world on one hand, and perceptions on the other. I've heard talk of "naive realists"--though I've never met one in the flesh--but is that even an option? Once I've accepted this dualism (and it is just the old mind-matter dualism in a new guise), what's left for me? I see only one viable choice: representationalism. If you start talking about the "world" and our "perception" of it, when you look at the two rows of figures, representationalism appears to be the only reasonable conclusion. It's axiomatic--no argument is required.

Derrick, against whom do you war? Who holds a theory of perception that is not representationalist? --And I am asking for a well-defended and well-developed philosophical position, not the mythical "naive realist". (My dear naive realist, if you are out there, we really must talk.)

2010-10-27
The time-lag argument for the representational theory of perception
"With respect to step 2, do you disagree that the event occurs in the observer's visual field between T + 100 ms and T + 101 ms (bearing in mind the distinction made in my 17 Oct post between field of vision and visual field)?"

Yes, its this point that is dubious.  My experience always contains the time of the flash, not the flash plus 100ms.  If the flash illuminates a clock it is the time on the clock at the instant of the flash that is in my experience.  Your argument requires a proof that my experience is indeed 100ms late.

2010-11-01
The time-lag argument for the representational theory of perception
Annette:

a) I agree that the anatomy of the word 'representation' suggests that this term is referring to a re-presentation, but I don't see how it suggests that that re-presentation has to be made to the same thing that the original presentation was made to. The representative theory of perception claims that we directly experience visually a re-presentation of what was presented to the eyeballs a fraction of a second earlier. I think you said in an earlier post that a photograph of a place that I'd never seen before was a representation, because the image had been originally presented to the photographer. But the photographer and I are two different things, just as my retina and my mind are two different things. Indeed, if I walked blindfolded into a room that I've never seen before, then took a photo, and then left the room, then I would rightly regard the resulting photo to be a representation of the room, even though the image had never been presented to any mind at all, only the light sensor in my camera.

b) Your objection wouldn't apply against the use of the term 'mental image', and yet an image is a form of representation.

c) Someone once said that words are our slaves, not our masters. Ultimately, the meaning of a word is dictated not by its anatomy, but by the definition that we agree to attach to it.

But thanks for the objection - it is at least amusing.

By which I of course mean that your objection is worth musing over - as I have just been doing! :-)


John:

'Your argument requires a proof that my experience is indeed 100ms late.'

I don't follow - are you saying that you also don't accept step 1? If you do accept step 1, I don't follow why you don't believe that the event occurs in your visual field 100 ms after it occurred in the field of vision, given that the latter is the input to the visual process and the former is the output, and the visual process takes 100 ms.


Peter:

'Who holds a theory of perception that is not representationalist?'

I agree with you that direct perception doesn't make sense even conceptually. However, it is a position that is held by the great majority of philosophers of mind, and virtually all non-philosophers, and so it is certainly worth trying to show that it is false.

2010-11-02
The time-lag argument for the representational theory of perception
Derrick, I agreed that a photgraph of a place I have not myself seen is indeed a representation, its earlier presenation having been to the photographer (and anyothers who had seen the place). But your eyeballs are not perceivers, only aids to a perceiver, so that the scene impinged on them does not mean it was presented to a perceiver. Glad to give you amusement, Annette

2010-11-02
The time-lag argument for the representational theory of perception
Derrick said:

Peter:

'Who holds a theory of perception that is not representationalist?'

I agree with you that direct perception doesn't make sense even conceptually. However, it is a position that is held by the great majority of philosophers of mind, and virtually all non-philosophers, and so it is certainly worth trying to show that it is false.

I am certainly sympathetic to your intentions, Derrick. But how can you refute a position that "doesn't make sense"? I'd say that the first duty of a philosopher is to understand the opposing position. It may not be possible to understand a certain philosophical position; but then it is incumbent on the philosopher to show that the position is nonsense, not that it is false. If you think that you have refuted these "realists" by proving that representationalism is true, how do you know that they are not--in their muddle-headed and nonsensical way--agreeing with you? Or perhaps they are interested in something altogether different than the concerns addressed in your argument.

I must make a confession: you say that there are a great many philosophers who hold a "realist" position; I was not aware of this. Perhaps it is a recent fashion of philosophy? I studied philosophy in the distant days of my youth, but then gave it up after a couple of frustrating years of being treated like dirt as "adjunct faculty". (I then got a "real" job--as Wittgenstein advised. I was still treated like dirt--but the wages were vastly superior.) Now, I'm retired, and taking a peek at philosophy every now and then. So if realism is a majority view these days, I can understand how I might have missed the change. I had thought pretty much everybody was a representationalist of some sort. Perhaps the realists were always out there, lurking, and I was oblivious to them. (I think Reid was probably a realist in the sense we are discussing...but he was safely dead already when I was a student.)

Could you possibly direct me to a paper or two that are available online--or at least purchaseable-- that present the best possible case for modern realism? I'd like to understand them better.

By the way, I notice you haven't addressed my comments regarding Berkeley. What sort of theory do you think he held? Yes, I know it's called "idealism"...but as I think about Berkeley, I realize he might be one of your opponents--for isn't his theory a realist theory? It's clearly not representationalist. According to the good bishop, we perceive the universal furniture directly, because the entire universe--including us--is made of mind-stuff. That's a sort of realism, isn't it? Somehow, I had never before thought of Berkeley as a realist...perhaps I thought one would have to be some sort of materialist to be a realist, but why should I believe such a silly thing? So maybe there is one realist I already sort of understand. (The qualifier means I don't really understand his theories, I can't possibly admit that! But I do remember what he wrote, and I'm perfectly willing to use him as a weapon.)

So, does your argument refute idealism, Derrick? Yes, I'm serious. I'm even willing to become an idealist (for a short time), if that's what it takes.

2010-11-04
The time-lag argument for the representational theory of perception
Derrick: "I don't follow - are you saying that you also don't accept step 1? If you do accept step 1, I don't follow why you don't believe that the event occurs in your visual field 100 ms after it occurred in the field of vision, given that the latter is the input to the visual process and the former is the output, and the visual process takes 100 ms."

In this thread you are exposing your argument to inspection so, fortunately, I do not need to propose alternative models of perception and my beliefs about perception are irrelevant.  I am saying that your argument has not shown that visual experience is the same as the events that occur 100ms after the flash.  Without this identity between experience and physical events at 100 ms your argument is false. 


2010-11-04
The time-lag argument for the representational theory of perception
Annette:

But what is the basis of your belief that a representation has to be a re-presentation of what was previously presented to a perceiver? As I said, the representative theory of perception claims that we directly experience visually is a re-presentation of what was presented to the eyeballs a fraction of a second earlier.

Also, in the case of the blindfolded photographer, you seem to be saying in your last post that the use of the term 'representation' to describe the photograph can be justified because other perceivers have seen the room. But this logic leads to the conclusion that the proposed mental image that we experience during visual perception can also be described as a representation - at least, in circumstances where a scene has been perceived by others.

Also, how would you respond to point b:
Your objection wouldn't apply against the use of the term 'mental image', and yet an image is a form of representation.


2010-11-04
The time-lag argument for the representational theory of perception
Derrick, one has to give some sense to the "re" in representation. What is represented must first have been presented. I do not think mental images are involved in sense perception, except in that future ones, say in memory, are made possible. Then there is an image or representation of what had earlier been directly perceived.   Annette

2010-11-08
The time-lag argument for the representational theory of perception
Peter:

Sorry, my choice of words could have been better. When I say that direct perception doesn't make sense even conceptually, I don't mean that the theory is completely incomprehensible.

I can easily understand what the theory is saying when considering perceptual experience. For example, in the case of vision, it's saying that what you directly experience simply is the scene in front of your eyes, whereas the representative theory of perception is saying that it is merely a mental representation of that scene.

However, I can't myself make sense of direct perception when I consider the perceptual process. For example, in what sense can perceptual experience be direct when it is immediately associated with activity in the brain, and therefore only indirectly associated with the world which caused that activity?

I don't want to get into a discussion here about this last point - as I said above, the specific subject of this thread is the question of which steps in my formulation of the time-lag argument are false. I'm just trying to explain what I was meaning in my last post.

Perhaps a good outline of the majority position is this paper:
Le Morvan, P., 2004, 'Arguments against direct realism and how to counter them', The American Philosophical Quarterly, 41:3, 221-234
Re Berkely and idealism, I think I've already drifted off topic enough in this post! You could always start a new thread on these topics.

2010-11-08
The time-lag argument for the representational theory of perception
Annette: "I do not think mental images are involved in sense perception, except in that future ones, say in memory, are made possible."

Neuroscience shows that the same areas of the brain are largely used when imagining as are used for sensation so if Annette is prepared to let Derrick have re-presentation of memory then re-presentation of sensation is a reasonable supposition.  It is now incumbent upon Direct Realists to provide actual experimental evidence for their case to counter the wealth of evidence available for representationalism.

Had Derrick used the late phase of the  ERP in his examples I would also have been happy for him to correlate neural activity with visual experience because there is ever increasing evidence that experience is about 0.5 seconds late compared with events in the world (from Libet to perceptual masking to correlates of the P3/4 phases of the ERP etc.).  Incidently, this means that experience is also about 0.2-0.3 secs late compared with behavioural reactions.

The real issue is how the 'form' of experience could be generated by any substrate, whether that be things directly in the world, sets of activity in the brain or some mystical dualist substance.  Experience has the geometrical form of a 'view' and this form is a physical impossibility if school maths and physics are used to describe it.  Philosophy largely reacts to this problem by either declaring that experience cannot be happening (eliminativism) or with mysticism but of course experience happens and it is a physical form but we are too dumb at the moment to explain it.

2010-11-08
The time-lag argument for the representational theory of perception
John:

Sorry, I still don't follow.

I was asking if you disagreed with step 1, and you don't say in your reply that you do, so I'm assuming you don't.

(If this is not the case, then please let me know, explaining why you think it is flawed.)

But if you accept that your vision of the flash is dependent on a process which takes 100 ms, then why I don't see why you think step 2 is flawed:
2) Therefore, if the additional illumination of the field of vision occurs between the points in time T and T + 1 ms, then it won't occur in your visual field until 100 ms later, between T + 100 ms and T + 101 ms


Annette:

You wrote:

'one has to give some sense to the "re" in representation. What is represented must first have been presented.'

I agreed with this above. My position is that the mental representation is a re-presentation of what was presented to the eyeballs a fraction of a second earlier.

You then replied that the original presentation has to be to a perceiver, and not just an eyeball, and my question about this position was:

What is the basis of this stricter requirement? That is, what is wrong with saying that the mental representation is a re-presentation of what was presented to the eyeballs a fraction of a second earlier?




2010-11-08
The time-lag argument for the representational theory of perception
Here is version #387:

  1. The process of visual perception takes 100 ms when viewing your immediate surroundings.

  2. Therefore, given that the field of vision is the input to the visual process, and your visual field is the output, visible events in the field of vision won't occur in your visual field for 100 ms when viewing your immediate surroundings.
  3. The light pulse from a camera flash has a typical duration of 1 ms, and the brief additional illumination of your immediate surroundings by a camera flash is a clearly visible event.

  4. Therefore, if, when viewing your immediate surroundings, the field of vision receives additional illumination from a camera flash between the points in time T and T + 1 ms, then this event won't occur in your visual field for 100 ms, occurring between T + 100 ms and T + 101 ms - as this diagram shows:

  5. However, a specific event occurs solely between two specific points in time, and so can't itself also occur between two later points in time.
  6. Therefore, if the event in reality occurs between T and T + 1 ms, then what occurs between T + 100 ms and T + 101 ms in your visual field can't literally be the event itself.

  7. Therefore, what you actually experience visually between T + 100 ms and T + 101 ms must be merely a subsequent mental representation of the field of vision receiving the additional illumination between T and T + 1 ms.

  8. There's no reason why the fundamental nature of your visual experience of the scene in front of your eyes should change depending on the level of illumination of that scene.

  9. Therefore, your visual field must always be merely a mental representation of the field of vision at the start of the visual process.



2010-11-08
The time-lag argument for the representational theory of perception
Hi Derrick,
I think your time-lag argument supposes that there is a partition between the perceiver and the perceived.
To understand this let us try to define this "partition" or boundary between outside and inside as it were. At what point can we confidently say that the light as "visual information" penetrates this supposed boundary? Is it when it enters the lens of the eye - and then again the focus of the lens or is it when the focussed light impinges upon the retina?
Or should we go still further and ask, is it when the neurons from the retina are fired and pass their tiny electric currents individually into the optic nerve? We could go on further still into the brain and its processes, but I think you get the point.
To illustrate, let us visualise a cone, in which the apex of the cone is the point of observation, and, in regard to time-separation, let this observer be the apex point and who believes himself to be in the "present", the "now" moment. Then every point on the cone that extends outwards from the observer will lie in his past.

The problem is the partition between observer and observed.

Einstein admitted that he could never quite understand the meaning of "now". To me, among other things, this amounts to not being able to understand the idea of a "point observer". The "other things" being the finiteness of any "signal speed", which Einstein defined as a Universal Limit - that is 'c', the speed of light

Best Wishes

Rajiv Pande

2010-11-08
The time-lag argument for the representational theory of perception
Derrick and John: Why do I say that what impinges on the eyeballs is not a presentation? For the same reason I would not call digestion a presentation. Both are just causal processes, where no perceiver takes herself to be co-present with something, as we do in sense perception. And, John, even if the same areas of the brain are activated in memory as in sense perception, since we take the remembered to be past, there must be some brain-correlate of that sense of past-ness, not there in sense perception. (But Derrick seems to think it should be.) Memory re-presents or images what was earlier sensed, so taken as present with us, and takes itself as an image. For every image there must be an original which is imaged.   But enough already, Annette

2010-11-10
The time-lag argument for the representational theory of perception
Reply to Rajiv Pande
Rajiv: "To illustrate, let us visualise a cone, in which the apex of the cone is the point of observation, and, in regard to time-separation, let this observer be the apex point and who believes himself to be in the "present", the "now" moment. Then every point on the cone that extends outwards from the observer will lie in his past."

This light-cone interpretation of perception was raised by Alex Green in the early noughties in numerous philosophical forums but she concluded that it was unpublishable.  Unpublishable work may be an indication of many things from an idea being genuinely original to the author being nuts!  Green was definitely 'compos mentis' but never discovered how to present the ideas in a manner that is acceptable.

Green's central point is that our experience is a geometrical form (a set of events arranged in space and time) that cannot be explained by school physics but which is by no means impossible if more advanced physical and mathematical ideas are used.  In other words the conventional wisdom that the space-time geometry of experience is inexplicable because it leads to regression within an homunculus is out of date.  I have made some effort to follow up Green's ideas but, like Green, do not have the style or have not found the correct approach to get it published in philosophical journals (or we are both nuts!).



2010-11-10
The time-lag argument for the representational theory of perception
Derrick, my problem with your argument is that you are just assuming that brain events are the cause of conscious experience.  The argument just assumes this causal connection without offering any evidence.

What is your evidence that conscious experience can be equated with events in the brain? 

I have asked this question before and you gave a reference to work which I pointed out was a non sequitur when we are discussing conscious experience.  I would suggest that Libet's experiments on the 0.5 second delay, experiments on perceptual masking and experiments on temporal "filling in" such as the MRI demonstration of the filling in of the moving lights in the phi illusion are the appropriate references for neural correlates of conscious experience.

However, if you present a convincing argument that conscious experience is due to neural events 0.5 secs or so after a flash of light, or any other stimulus, then your argument has become an argument about the correlates of conscious experience in the brain.  The "time lag argument" is then entirely superfluous.

(Your reference for 100 ms: Changizi, M., Hsieh, A., Nijhawan, R., Kanai, R.,&Shimojo, S., 2008, 'Perceiving the Present and a Systematization of Illusions', Cognitive Science: A Multidisciplinary Journal, 32:3, 459—503 .  They refer to Lennie, 1981; Maunsell &Gibson, 1992; Schmolesky et al., 1998, none of which prove anything about conscious experience - unless they all had a new breed of talking macaque monkeys! - look them up)



2010-11-10
The time-lag argument for the representational theory of perception
Hi Derrick,

You asked Annette: "That is, what is wrong with saying that the mental representation is a re-presentation of what was presented to the eyeballs a fraction of a second earlier?"

I believe it's that "scenes" are presented or re-presented to consciousness, rather than to eyeballs. Conscious perceivers have mental presentations and re-presentations, whereas eyeballs do not.

Luke.

2010-11-10
The time-lag argument for the representational theory of perception
Annette: "Both are just causal processes, where no perceiver takes herself to be co-present with something, as we do in sense perception."

Nicely put; in a simple causal process one event follows another so a simple causal processor is always in a state that is later than the event that it is processing.

Our experience differs from a simple causal process because it has an extended present moment: we hear whole bars of tunes and the simultaneous parts of views occur in the form of visual space.  Philosophers seem to like to call this extended present "specious" although it is definitely there and would be expected according to our modern physical knowledge.

2010-11-29
The time-lag argument for the representational theory of perception
Rajiv:

I think I follow your objection, but I don't believe it applies to the argument as I've presented it. That is, which steps in the argument do you believe implicitly depend on the assumption of such a partition?

John:

I feel that the reference I use for the lag in visual perception is a good one, so I think we'll have to agree to disagree on this one. :)

Luke and Annette:

I'm afraid that I still don't follow this objection. As I said above, the objection obviously doesn't apply to the term 'mental image', so you wouldn't be able to make this objection to the argument if I used this latter term instead. However, an image is, by definition, a representation. Therefore, if I then changed 'mental image' to 'mental representation', this change wouldn't at all have changed the meaning of the steps which use this term, and so there is no reason why an objection which doesn't work against the previous wording should work against the 'new' wording.

2010-11-30
The time-lag argument for the representational theory of perception
Derrick, what you have not made clear is the link you see between the time lag (undisputed) in sense perception, and the claim that what is before the mind in sense perception is a "mere representation." Would you regard it as something more than that, at least as a presentation, if there were no time lag? Or do you think all that minds can ever, in any conditions, have present to them are representations, mere images or some outside reality? Your terminology, with a contrast between field of vision and visual field, suggests that the imaged is in the real field, while vision is confined to images. But what role does the time lag play? Is our vision of stars more clearly a "mere representation" than our vision of what is closer to us? Its the link between time-lag and being confined to mere representations, to images rather than the imaged, which you have not spelt out to us. Annette B. . 

2010-12-03
The time-lag argument for the representational theory of perception

Dear Derrick,
In your presentation of the Time-lag argument you wrote:

1) One's vision is dependent on visual information travelling from one's eyes to the visual areas of one's brain, and then being processed, all of which does not happen instantaneously, but takes a finite amount of time, however small.

and ....For example, the visual lag is about 100ms, or 0.1s

The Idea of a partition implies that there is a point where we begin to measure the time-lag and a point where we end the measurement.

This is the same situation faced by Einstein when he postulated the space-time manifold as a continuum of points. Every point in the Space-Time continuum is a potential point that can be observed (potential object) and every point is also a potential observer (potential perspective). By definition of a continuum, no point in the continuum has any privileged distinction over any other point so that any given "observer" cannot be regarded as distinct from what is "observed" by the observer.
 
Since you are concerned about the "present" and about the visual image being in the past (relative to the present), I am assuming that you regard the temporal location of the observer as being in the present instant or the present moment - a "now" in time (which also supposes a "here" in space)

This is the exact same paradox that appears in Einstein's General Relativity. If we want to identify a "here and now" as a privilege of an observer within the Space-Time continuum, then we must also be constrained by time-lags due to the limiting speed of light. Alternately if we want to avoid time-lags, we must subsume observer and observed into a single continuum - that is, deny that an observer has any privileged "here and now" and obtain an "everywhere, all-at-once" perspective.

Regards
Rajiv


2010-12-03
The time-lag argument for the representational theory of perception
Hi Annette

You're saying that I don't make clear the link that I see between the visual lag and the claim that visual experience is of a mental representation of the scene in front of the observer's eyes. However, the argument (the latest version of which was posted on 8 Nov) starts with the visual lag and then proceeds through eight steps to reach this claim. Of course, you may not think that my chain of reasoning is sound, but it's not true that I don't present my reasoning.

The question which is the intended sole subject of this thread is: Which step, or steps, in this reasoning is flawed, and in what way?

As I said above, it would help keep this thread focussed if people could post objections along the lines of: 'I think step X is flawed because Y'.

I'm not sure from your last post which specific step, or steps, you find flawed, and why.

You did earlier raise a general objection to the term 'mental representation', and my previous post contains a response to this objection.

2010-12-03
The time-lag argument for the representational theory of perception
Derrick, I can understand that you do not wish to discuss the reference you used for the lag in visual perception.  Your 'reference' is indirect, being a reference to references that cover about three sets of experiments in macaque monkeys and is irrelevant to conscious human visual experience. However, had you produced a valid argument for the correlation between a particular set of electrical activity in the brain and conscious visual experience the time lag argument would then be irrelevant:  if conscious visual experience is a set of brain activity then it is not directly objects in the world.

Annette, is there any way of knowing any object in the world outside our bodies except by examining the change of state of probes?  In fact, physical research tells us that if the tiniest component parts of the world are isolated and stopped they can immediately be anywhere in the universe, their state is indeterminate.  It is only the interaction of these tiniest components with measuring probes in the form of the "environment" that makes their state determinate.  This means that what we believe to be the physical world beyond our bodies is already a "representation", not things in themselves.

2010-12-03
The time-lag argument for the representational theory of perception
Derrick, it is your steps 6&7 that worry me. 6 says that, given the time lag, it cannot be "the event itself" which is in the later field of vision of the perceiver. Then 7 says it must therfore be a mere representation. Why not a delayed presentation? I could understand it if you thought sense perception, with its time lag, contrasted with some instantaneous cognition, say my knowing what I am now thinking. Or even if you argued that since the perceiver takes what is in her field of vision to be a present event, and is wrong about that, what she has is a false version of what is now happening, and a misrepresentation of the time of occurrence of what did just occur. Flase representations must be representaations. But now you have taught me, I do not make that error, so take what I am seeing of what is close to me to be what it was like a split second ago. What makes it a representation of that event, rather than a normally slowly arriving truth? It is step 7 which seems to me the non-sequitur. Annette  

2010-12-09
The time-lag argument for the representational theory of perception
Hi Derrick, You asked that we approach the propositions step-wise, so let me do just that. "1) One's vision is dependent on visual information travelling...which does not happen instantaneously, but takes a finite amount of time, however small..." Here is the initial assumption: finite speed of signal/stimulation. "2) Therefore, the content of one's vision in the present is always the world of the past, however recent." Here is the second assumption: that an observer is located in a distinct "here" and "now" "3) The past, however recent, cannot itself exist in the present, by definition, although a representation of it can." This follows from Assumptions 1 and 2 "4) Therefore...must instead be merely a mental simulation of it" If assumptions 1 and 2 are correct, then the conclusion of step 4 is correct, provided we look at “Simulation” as an artefact of perception, that is, a construction of some kind In order to understand where you want to go with all this, I would like you to choose between the two meanings of “artefact” from the choices given below: 1. Any object made by human beings, esp. with a view to subsequent use. 2. A spurious observation or result arising from preparatory or investigative procedures ....OR... any feature that is not naturally present but is a product of an extrinsic agent, method, or the like: such as statistical artifacts that make the inflation rate seem greater than it is. The first gives some “value “ or usefulness to perception, the other treats it as an illusion or unreality of some kind along the lines of what is called “Maya” in Hindu Philosophy

2010-12-14
The time-lag argument for the representational theory of perception
Annette, the real problem is "knowing what I am now thinking".  If the present moment is instantaneous could you ever know what you are now thinking?  You yourself have described the problem of causal chains in which the result of a process is always later than the event it is processing: this insight means that any simple model of processing in  perception will end up with an infinity of homunculi viewing our sense data, each of which contains a meaningless instantaneous event that is later than the last. This homuncular regress would occur as a result of a simple processing model whether the data in perception is objects in the world beyond the body, brain activity or any other set of events at an instant. 

I would define a "presentation" as a series of instantaneous events and a "mental representation" as perceiving these events in a way that avoids homunculi.  We know from our own experience that the mental "now" is not instantaneous so I would propose that "mental representations" are sets of presentations extended in mental time. This would give you the time to know what you are thinking, both just now and then.  I agree with you that Derrick's argument does not discuss how a presentation becomes a mental representation, it does not even correlate any of the sets of events with conscious experience let alone justify how a correlated set of events actually becomes that experience.

2010-12-14
The time-lag argument for the representational theory of perception
Rajiv:

You're referring to an older version of the argument - could you please have a look at the version that I posted on 8 November, and let me know which step, or steps, of that version you disagree with. For example, the latest version doesn't refer to the past and present. Thanks in advance.


John:

I note what you say about the reference, but still fee that it is a good one, and that we should agree to disagree.

Re you other point, could you state which step, or steps, in the latest version of the argument - posted on 8 November - you think are wrong, and why.


Annette:

You ask why the occurrence of the event in the observer's visual field between T + 100 ms and T + 101 ms must be a mere representation of that event. The answer is provided by step 5:
However, a specific event occurs solely between two specific points in time, and so can't itself also occur between two later points in time.
The event in reality occurred between T and T + 1 ms, and so what occurs between T + 100 ms and T + 101 ms in the observer's visual field cannot be the event itself.

I think you might have in mind the same objection that I address in the article:

You might be tempted to object to this argument as follows.

Your visual experience of the scene in front of your eyes of course necessarily involves information about that scene travelling to your brain, via your eyes, and then being processed, all of which of course takes a small amount of time. However, given that your visual experience is therefore directly linked to the scene, via the perceptual process, the experience is still direct, even if it is necessarily a direct experience of the scene a fraction of a second ago. That is, what follows from the visual lag isn't that you cannot visually experience the world directly, but simply that you cannot visually experience the world directly without this very slight delay. The existence of the visual lag is only fatal for any naive theory of direct perception which requires that perception is instantaneous.

Therefore, with respect to your vision of the brief additional illumination of the scene in front of your eyes from a camera flash, what actually occurs between T + 100 ms and T + 101 ms is simply your direct visual experience of this event occurring between T and T + 1 ms, rather than a problematic second occurrence of the event. The above argument is based on the hidden false assumption that the thing that you're directly experiencing perceptually must be absolutely simultaneous with that perceptual experience, which leads to the false claim in step 4 that the event must occur between T + 100 ms and T + 101 ms in your visual field.

However, to say that you visually experience this brief additional illumination of the scene in front of your eyes is to say that this event occurs at some point in time in your visual field. But, as stated in step 2, given that the field of vision is the input to the visual process, and your visual field is the output, visible events in the field of vision won't occur in your visual field for 100 ms when viewing your immediate surroundings. Therefore, if this event occurs in the field of vision between T and T + 1 ms, then it won't occur in your visual field for 100 ms, occurring between T + 100 ms and T + 101 ms - as stated in step 4, and shown in the diagram. That is, the claim that the event must occur in your visual field between T + 100 ms and T + 101 is not based on the mere assumption that the thing that you're directly experiencing perceptually must be absolutely simultaneous with that perceptual experience, but solely on steps 1 and 2.

For example, imagine that you were somehow able to make a high-speed video recording of your visual field before, during, and after, your visual experience of the event. The camera flash is connected to the recording equipment so that the firing of the flash starts a timer which is superimposed onto a corner of the recorded image, and which counts in milliseconds. The signal from the flash will only take a tiny fraction of a millisecond to reach the recording equipment. If you were to then play the video back in slow motion, you would see the 1-ms-long additional illumination of the scene occurring in the video when the timer reaches 100 ms.

Therefore, there is indeed a problematic second occurrence of the event between T + 100 ms and T + 101 ms.



2010-12-21
The time-lag argument for the representational theory of perception
Derrick, you asked what step was wrong. Step 7 is entirely unsupported:

"Therefore, what you actually experience visually between T + 100 ms and T + 101 ms must be merely a subsequent mental representation of the field of vision receiving the additional illumination between T and T + 1 ms."

You have not justified the assertion that there is experience between 100 and 101ms after the event. Any Direct Realist can just assert the opposite, that experience is at 0ms-1ms. 

Step 7 is an assumption.  If this assumption were true then all the other steps are pointless.  You could just say:

"People do not see a flash, they see events at 100ms after the flash that they call 'the flash'"  That is enough of an argument.

But you have not proven that the assumption is true so your argument fails.  You cannot prove that Direct Realism is false by simply assuming that Indirect Realism or Representationalism is true.

This assumption is present in all of your arguments above. As an example you say "Your visual experience of the scene in front of your eyes of course necessarily involves information about that scene travelling to your brain, via your eyes, and then being processed, all of which of course takes a small amount of time. "  If I were a Direct Realist I would simply say "Rubbish, my experience is a flash directly in the world, either instantaneously or transtemporally.  All this stuff about T+100 is about behavioural reactions and has nothing to do with my conscious experience".

2010-12-30
The time-lag argument for the representational theory of perception
John

You write: 'You have ... (expand) not justified the assertion that there is experience between 100 and 101ms after the event. Any Direct Realist can just assert the opposite, that experience is at 0ms-1ms.'

I think that the occurrence of the visual experience between T + 100 ms and T + 101 ms was established in step 4:
Therefore, if, when viewing your immediate surroundings, the field of vision receives additional illumination from a camera flash between the points in time T and T + 1 ms, then this event won't occur in your visual field for 100 ms, occurring between T + 100 ms and T + 101 ms.
This step is in turn justified by steps 1 to 3.

I don't think any of the steps in the argument assume that the representative theory of perception is true, but build on each other to reach that conclusion.

Re your last point, my argument doesn't anywhere refer to behaviour, but solely to the visual process and conscious visual experience. Re the imagined quote, I don't follow which step in the argument it is criticising.

Derrick

2011-01-06
The time-lag argument for the representational theory of perception
Derrick, you say that the occurrence of delayed visual experience was established in step 4 but step 4 just assumes that visual experience is delayed.  In step 4 you just baldly state that events won't occur in your visual field for 100 ms:

step 4: "Therefore, if, when viewing your immediate surroundings, the field of vision receives additional illumination from a camera flash between the points in time T and T + 1 ms, then this event won't occur in your visual field for 100 ms, occurring between T + 100 ms and T + 101 ms."

You say your argument applies to "conscious visual experience" but you offer no evidence that anything that occurs at 100 ms is "conscious experience". Without this crucial correlation, between physical events at 100ms and conscious experience, any direct realist can simply dismiss your argument on the basis that it assumes indirect realism rather than proves it.




2011-01-11
The time-lag argument for the representational theory of perception
Here is a cartoon summary of the theory of representationalism that refutes many of the classical objections.

http://cns-alumni.bu.edu/~slehar/cartoonepist/cartoonepist.html

  Steve Lehar

2011-01-22
The time-lag argument for the representational theory of perception
John

It isn't true that I said, as you claim, 'that the occurrence of delayed visual experience was established in step 4'.

I said in my previous post that the occurrence of a specific visual experience of a specific event at T + 100 ms was established in step 4.

It is true that step 4 'just' assumes that visual experience in general is delayed by 100 ms, but this is because this was established in steps 1 and 2.

You say: 'you offer no evidence that anything that occurs at 100 ms is "conscious experience"'. However, the argument establishes that the event occurs in the visual field at T + 100 ms, and the visual field is our conscious visual experience. As I quoted from the article in an earlier post:

It's important at this point to define two closely related, and often confused, terms: 'field of vision' and 'visual field'. The field of vision is the input to the visual process - the area of the world that you are experiencing visually - whereas the visual field is the output of the visual process - your visual experience. Indeed, one's visual field doesn't always match the field of vision, as in the case of visual field defects, or when an hallucinated object appears in one's visual field.

So, given the 0.1 s delay in visual perception, your visual field lags behind visible events in the field of vision by 0.1 s.

2011-01-24
The time-lag argument for the representational theory of perception
Derrick: "the visual field is the output of the visual process "

This is a repeat of the assumption of Indirect Realism/Representationalism that you make in step 4.    If I were a Direct Realist I would need you to provide solid evidence of a cast-iron correlation between the physical events that are the "output of the visual process" and visual experience.  Without such evidence I would be justified in declaring that your argument is no more than saying that if you assume Indirect Realism then a "time-lag" in perception would be consistent with this assumption.

Incidently, have you read Le Morvan's arguments for Direct Realism www.tcnj.edu/~lemorvan/DR_web.pdf ? Rather than the blatant denial of the role of the visual process that I have used above he counters the time lag argument by admitting that time lags may occur and then denying that this undermines Direct Realism.

2011-01-24
The time-lag argument for the representational theory of perception
Hi Derrick

Thank you for inviting me to join the debate, you must know of my own interest in representationalism. Unfortunately I only had time to skim the long debate that precedes, but I have some points to make on your initial argument at the head of this thread.

Your entire argument (with which I of course agree) is based on a representationalist assumption and thus is sure to ring hollow to a dogmatic naive realist. I presume you are familiar with my Cartoon Epistemology?

http://sharp.bu.edu/~slehar/cartoonepist/cartoonepist.html

I thought the tall thin guy made an irrefutable case, but the little fat guy always had a rejoinder, even if we see it as absurd. This is a paradigmatic issue, like, for example, the belief in God. At the end of a long debate with believers, no matter how conclusive, the believer always ends with "Yes but I know He exists!" Because that is not their *conclusion* after a chain of logical reasoning, that was the *initial assumption* with which they came to the debate in the first place! That is a "fact" that they see as *self evident* and they are puzzled how anyone could possibly challenge it. And so it is with naive realists, who begin with an absolute certainty that the world in their experience is real, and they will go to no end of articulations in order to justify that view by logic. After you've heard their arguments long enough, you can almost predict the objections they will raise. For example your Point 1) One's vision is dependent on visual information traveling from one's eyes to the visual areas of one's brain, and then being processed, yes that sounds irrefutable, but the naive realist would quietly assume the proviso "yes but what I am seeing is not the end product of that causal chain, I am seeing the root cause of that chain, the objects reflecting light, directly in my experience!" and thus the entire argument collapses from the outset *for them*, and we are left befuddled as to how anyone could possibly not understand the causal chain of vision. I suspect the preceding debate above is replete with examples of this paradigmatic impasse, and let me guess: After all the debate, has any naive realist been persuaded? The REAL debate is the paradigmatic issue itself, and that, you will find, is not open to debate. That is their initial assumption, the rest is a rationalization of that assumption.

One fine point in your initial point 2) requires some refinement. Yes the world of experience is always in the past, but it is also in the nature of experience to predict the future, as most clearly evidenced in the phenomenon of *smooth pursuit* eye movements. When watching a moving object, or even one swinging back and forth periodically, your eyes do *not* track the past position of the object lagged 100 ms into the past, your mind picks up on the predictable motion, and points your eyes into the position where it knows the object will be in 100 ms, and thus they are tracking the *present* position of the moving object as seen into the *future* from the *past*. And THAT is why we don't notice that our experience has a temporal lag. (If the object moves in an irregular or unpredictable trajectory then your eyes do in fact lag in their tracking). This fine point somewhat muddies the otherwise clear chain of your logic. For a more complete exposition check out the Plotting Room Analogy:

http://cns-alumni.bu.edu/~slehar/webstuff/book/chap1.html#PLOTTINGROOM

You will never convince the naive realists, especially the dogmatic ones who feel compelled to wade in to these debates, but these debates are not as futile as they might seem, because of the much larger number of "lurkers" who witness the debate from the sidelines, some of them have never heard these arguments before (this stuff is not taught in school, not in psychology, philosophy, nor neuroscience!) so they are the ones most likely to be persuaded.

As to the intuitive power of the naive realist instinct, check out the History of the Epistemological Debate...

http://cns-alumni.bu.edu/~slehar/webstuff/consc1/consc1a.html#hist

You may be surprised to discover that this is an ancient debate that has gone round and round in futile circles for centuries. It is the single central core issue in the science of perception, which will continue to be befuddled and confused until this issue is finally resolved.











2011-02-07
The time-lag argument for the representational theory of perception
John:

Is it the case that you don't agree that visual experience is the output of the visual process?

Steven:

Thanks for your post - very interesting. I've actually been revising the argument as this discussion has proceeded, and the latest revision was posted on 8 Nov. Any thoughts on that would be gratefully received.


2011-02-09
The time-lag argument for the representational theory of perception
Derrick: "Is it the case that you don't agree that visual experience is the output of the visual process?"

What I am pointing out is that you have not demonstrated in your argument that visual experience is the output of the visual process.  The argument you have presented assumes that visual experience is the output of the visual process but does not prove this step. If you are going to assume that visual experience is the output of the visual process you are simply assuming representationalism from the outset and the rest of your time lag argument adds nothing.

2011-02-14
The time-lag argument for the representational theory of perception

What we are seeing here is a classical case of a paradigm debate, with people arguing at cross-purposes due to profoundly different initial assumptions, when it is actually those initial assumptions that are the at the core of the debate.

JWK Matthewson >>
What is your evidence that conscious experience can be equated with events in the brain?  

<< JWK Matthewson


What is your evidence that it is NOT?


This case cannot be *proven* either way. Some people simply assume it to be true, others assume it to be false. Nobody has ever proven either to be true. But paradigm debates are NOT ABOUT PROOF, they are about which paradigmatic hypothesis provides the most reasonable account of how vision works, it requires *judgment* (not proof) to decide between them.


In other words, is it more reasonable to assume that experience is identically equal to electrical activation in your brain, or that experience exists outside of your head, out in the world where we experience it to be, rather than in our head?


The reply to JWK Matthewson should be "If experience is not in the brain, then where else is it?" The alternatives are fraught with profound philosophical paradoxes: Experience is located out in the world, where it is undetectable by physical means (we can't see anyone ELSE's experience, only our own), that means that experience is like a ghost, or spirit, that can never be proven to exist or not. It is an unfalsifiable hypothesis, because its "prediction", that nothing will be detected, is identical to the NULL hypothesis that nothing is projected. JWK can still choose to believe it, as he may believe in his immortal soul, but if so, he is believing in something profoundly paradoxical that is in principle beyond scientific scrutiny. An article of *faith*, not a scientific hypothesis.


Those of us who believe, on the other hand, that experience is identically equal to patterns of physical energy in the physical brain, THAT is a scientific hypothesis that IS falsifiable, at least in principle, and it places experience at the very same location where the neural wetware exists that is responsible for the coming into existence of that experience, so thats where we should go look to find the physical basis of experience. That, it seems to me, is a FAR more parsimonious hypothesis, one most consistent with Occam's Razor, one that does NOT require the existence of invisible undetectable experience projecting invisibly out of people's heads contrary to anything else ever observed in science.


But paradigm debates are based on *judgment* -- for JWK it may still seem more reasonable to assume that the world he sees around him is the world itself, and nobody can ever persuade him otherwise.


It is very much like the debate in the last century whether life was just a biochemical process, or whether life contained an essential "e'lan vitale" (vital essance, life force) above and beyond mere biochemistry. That debate was eventually won by *science*. The debate over experience is likely to also.


So although I believe that Derrick is right, and that he makes a persuasive case, it is only persuasive for those who already agree with his paradigm, it does not "prove" it to anyone who does not.


  Steve







2011-02-19
The time-lag argument for the representational theory of perception
Reply to Steven Lehar
Hi Steve Lehar,

I personally believe that conscious experience is correlated with neural output.  However, this thread is about an "argument" and it is evident that the argument is flawed because it simply assumes that neural output is correlated with conscious experience.

There is plenty of evidence to show that the late phases of the Event Related Potential are indeed correlated with conscious experience but these are not discussed in the "time lag argument".  If we believe this evidence about the correlation between neural activity and experience (as I do) then the "time lag argument" is obvious and hence superfluous.  Direct Realists will have considerable difficulty arguing against the consequences of this "late phase" neural activity that becomes conscious experience.  (Consequences such as perceptual masking and the existence of subliminal perception and other non-conscious, cortical processing that occurs in the 0.3 - 0.5 second gap between events at the senses and conscious experience.)

To repeat, I am not a Direct Realist, I am merely pointing out that the "time lag argument" as presented here does not "hold water" and is, in any case, superfluous once a correlation between neural activity and experience is proven.

As for your question:  "If experience is not in the brain, then where else is it?", any Direct Realist would reply "somewhere else!" and there is no progress in the debate and no embarrassment for the Direct Realist.  I would take a different approach and ask "OK, you are a Direct Realist, explain perceptual masking and perceptual filling in without accepting that neural activity correlates with perceptual experience at +0.3-0.5 seconds".

The "time lag argument" gives the Direct Realist the dignity of saying "your argument is wrong" whereas the debate over the neural correlates of conscious experience leaves the Direct Realist simply rejecting the physical world.



2011-02-21
The time-lag argument for the representational theory of perception
Hi JKW Matthewson,
the "time lag argument" is obvious and hence superfluous.

Superfluous does not mean it is wrong. Obvious? Self-evident? Only to those who espouse that paradigm.

the "time lag argument" as presented here does not "hold water" 
Well now thats another matter entirely. Is there a flaw in the reasoning? A false initial assumption? Besides the assumption that experience is identically equal to electrochemical activity in the brain? Perhaps he is merely explaining why that paradigm offers the most parsimonious explanation of the ontology of conscious experience, one that does not require the existence of unobservable experiences that people experience as vivid three-dimensional colored moving structures.
As for your question:  "If experience is not in the brain, then where else is it?", any Direct Realist would reply "somewhere else!" and there is no progress in the debate and no embarrassment for the Direct Realist.
Quite to the contrary! Deep embarrassment! Where else could it possibly be than in the brain that is the causal origin of experience? One could simply say "in another dimension". But which dimension? And how does that dimension come into causal contact with events taking place in my physical brain? Why have these dimensions not been observed in any other physical experiment? If they can have an effect on my brain, surely they can deflect the needle of the right kind of sensor. Yes, direct realists *are* required by the laws of reasonableness to propose a location for their hidden dimension which stores, or buffers, three-dimensional spatial experiences of the degree of detail and fidelity as I see in the world around me right now. To propose that they are in no place that is visible at least in principle to scientific scrutiny, is an extraordinary hypothesis, which would require extraordinary evidence to convince the reasonable man. Otherwise, the most parsimonious hypothesis is that experience resides in the brain, as a physical process going on in the brain, and that in turn demonstrates that the brain is capable of fabricating three-dimensional moving colored images of experience.

The time-lag argument may be superfluous, although only to those who already subscribe to that paradigm. But there are plenty of naive realists, or eliminativists, who would deny conscious experience a physical existence in the universe known to science, for whom the time-lag argument is yet another fatal nail in their nail-studded coffin. Perhaps in that sense, the argument is superfluous. And yet the naive realist zombie still walks the earth!






2011-03-23
The time-lag argument for the representational theory of perception
John

I don't believe that I need to demonstrate that visual experience is the output of the visual process, because this is true by definition. That is, if it isn't true, then what else could be the output of the visual process? I therefore don't see why you think that believing that visual experience is the output of the process is to assume the representative theory of perception. A supporter of direct perception would say that their direct visual experience of the world is the output of the visual process.

2011-03-25
The time-lag argument for the representational theory of perception
I believe a Direct Realist would say that the phenomenon of visual experience is directly things arranged as they are in the space around a person and the behaviour that results from a visual stimulus is the output of visual processing by the brain.

Thomas Reid is the archetypal Direct Realist, he says:

"It is therefore acknowledged by this philosopher to be a natural instinct or prepossession, a universal and primary opinion of all men, a primary instinct of nature, that the objects which we immediately perceive by our senses are not images in our minds, but external objects, and that their existence is independent of us and our perception. (Thomas Reid Essays, 14)"

ie: he says visual experience is directly external objects, note the use of the word "immediately".

So Reid does not accept your statement that "visual experience is the output of the visual process", you must prove this point for your argument to be construed as any sort of attack on Direct Realism.  In fact the assumption that "visual experience is the output of the visual process" is an embedded assumption of representationalism/indirect realism in the argument.  This is unfortunate because it means that the argument reads: "if we assume that representationalism is true we find that representationalism is true".

If Direct Realists truly believed that visual experience occurred at the end of a chain of visual processes then surely there would be no argument about a "time gap". Direct Realists would simply accept that a time gap occurs and there would be no need for a "time gap argument".


2011-05-03
The time-lag argument for the representational theory of perception
John

If you don't agree that visual experience is the output of the visual process, then we'll have to agree to disagree. I don't attempt to prove this, because I believe that it is true by definition. I would say that visual experience cannot occur until every stage of the visual process has been completed. Indeed, if the optic nerve were severed, or the visual areas of the brain were removed, then there would be no visual experience, and so the time-consuming transmission of information along the optic nerve, and the subsequent time-consuming processing of that information in the brain, does indeed seem to be necessary for visual experience.

2011-05-04
The time-lag argument for the representational theory of perception
Derrick: "If you don't agree that visual experience is the output of the visual process, then we'll have to agree to disagree"

I personally believe that visual experience is indeed the output of the visual process but I am pointing out that Direct Realists believe that it isn't. Given that your argument is an argument against Direct Realism you cannot agree to disagree with their central thesis. Direct realism is defined as the proposal that visual experience is not the output of the visual process. In the Standord Encyclopedia of Philosophy BonJour(2007) says:

"Viewed as an alternative to representative realism in particular, direct realism involves two main theses. The first is a denial of the view referred to here as perceptual subjectivism: according to direct realism, in veridical cases we directly experience external material objects, without the mediation of either sense-data or adverbial contents.  ..."

I know this is absurd but Direct Realism really does posit experience without mediation. As Thomas Reid might have put it, the soul is believed to be directly connected with the world beyond the body.

I believe that the best arguments against Direct Realism are those that examine phenomena such as perceptual filling in and perceptual masking. In the first case we experience phenomena that definitely do not exist in the external material world but which are indistinguishable from it and in the case of the phi illusion 0.5 seconds delayed. In the second case we can blank out data after it has entered the brain provided the second, blanking stimulus occurs within about 0.5 secs.  The reason these physiological arguments are little used in philosophy is that they have the implication that all experience is 0.5 seconds delayed....which is true but awkward.  Your time gap argument could be modified into a "buffering within the brain for 0.5 secs" argument then it might indeed dispatch Direct Realism.

BonJour, Laurence, "Epistemological Problems of Perception", The Stanford Encyclopedia of Philosophy (Summer 2011 Edition), Edward N. Zalta (ed.), <http://plato.stanford.edu/archives/sum2011/entries/perception-episprob/>.

2011-05-08
The time-lag argument for the representational theory of perception
JWK: "I personally believe that visual experience is indeed the output of the visual process..."

I personally believe that you endorsed this statement just for dialog sake. "Visual process"!? This process does not exist and therefore nither actualy endure nor cause any time lag at all. Namelly, if we take photons to be the real /noumenal/ objects arriving and checking in at sense reception, their nature is telling us that as they are initially ariving at sense receptors they have no location whatsoever. Sensation itself creates spacetime picture depicting electromagnetic wave propagation so that space and time are created and encapsuled within that picture.

Visual experience is immediate product of creating the 4D perspective of e/m propagation

2011-05-11
The time-lag argument for the representational theory of perception
Aleksander:  "This process does not exist and therefore neither actually endure nor cause any time lag at all"

At last, a true Direct Realist to engage with this thread! 

How would you explain the filling in of the "blind spot"? Direct electrode studies show that the area of cortex corresponding to the blind spot is activated to "fill in" with the appropriate visual data.

How would you explain the phi illusion in which successively flashed but separated lights appear to be moving?  MRI studies show that the intervening areas of visual cortex are active during the phi illusion so that the brain "fills in" the movement between the positions of the lights.   The phi illusion disappears if the gap between flashes is more than about 0.5 secs, suggesting that the brain buffers visual data for this amount of time - in other words there is a time lag between retinal stimulation and experience of about 0.5 secs.  This time lag has been demonstrated in many other ways, for instance Libet et al showed a similar lag for direct brain stimulation that simulated cutaneous stimulation.

Incidentally, how would you explain an experience containing cutaneous sensation using an e/m propagation model. (I am not in disagreement with a 4D model of perception but would argue that this occurs inside the brain - see An introduction to New Empiricism).

2011-05-19
The time-lag argument for the representational theory of perception
But the point I'm making is that visual experience is by definition the output of the visual process, and so even supporters of direct perception would agree with this.

You say 'Direct realism is defined as the proposal that visual experience is not the output of the visual process.'

However, visual experience is clearly dependent on the visual process - e.g. we wouldn't have a visual experience if the information collected by the eyes didn't travel to the brain.

Therefore, visual experience is indeed the output of the visual process.

What you say above needs to be modified to: 'Direct realism is defined as the proposal that the content of visual experience is not the output of the visual process.'

2011-05-19
The time-lag argument for the representational theory of perception

>>>
 (see An introduction to New Empiricism

<<<


Ah! A clear exposition of the proposition! Well stated!


I have made a similiar proposition myself -- to explain the observed properties of conscious experience independent of a physiological explanation of how it happens in the brain.


Brief cartoon-like presentation:


Elaborate book-form presentation:


There are a couple of prominent features of the world of experience that help elucidate its true nature, which should be mentioned:


The solid spatial world of experience vanishes like a flash when we blink our eyes closed, and reappears in a flash when we open them again. This clearly distinguishes the objective external world from the world of experience which is a replica of it.


The part of the world that disappears (which is *everything!*) is the part that is subjective, behind your eyelids, internal to your head.


Second: Things in the distance appear smaller by perspective. Do you have any idea how *strange* that is? (despite its overwhelming familiarity)


Cartoon Epistemology


Third: Amodal perception. Our experience of a tomato (for example) is not confined to the red, round, and bulgy shape that appears as the exposed surface of the fruit, (the modal experience) but we also perceive the whole fruit as a complete solid object, complete with its hidden rear surface and volume of substance. (the amodal experience, because it is not experienced in a perceptual modality like the red color of the modal experience) This aspect of perception is vitally important to identify and distinguish from modal component because naive realists assume this portion of the experience to be the external object itself. Until that confusion is dispelled, there will be endless futile circular debate. This is explained in Chapters 1 and 2 of this book.


Fourth: The very existence of dreams and hallucinations offers irrefutable proof that the mind is capable of constructing full virtual worlds of color and volume and space, which are clearly not objectively real.


Put all those together, and you've got yourself an irrefutable argument that the world of experience is a virtual-reality replica of the world itself. Now you can start the debate whether that 3-d "picture" experience is constructed inside your brain (where the neural wetware resides) or whether it is projected magically out of your head to appear superimposed on the world it attempts to replicate in effigy (by way of invisible undetectable projection rays that also shrink in size with distance from the egocentric point! By the way, this is an unfalsifiable hypothesis because you can neither prove or disprove the existence of undetectable entities!)


You put all that together into a cast-iron irrefutable case, and the world of academia will simply ignore you and your argument as if they simply did not exist. This is a paradigmatic issue -- like religious belief. You can't convince them with logic and reason and irrefutable evidence, because they simply won't believe it. Believe me! I've spent an academic lifetime of being ignored! They will have to die and be replaced by a fresh new generation before the idea will ever take hold.


  Steve









2011-05-19
The time-lag argument for the representational theory of perception

Being aware of my inadequate command of English I do appreciate that you have bothered to answer my post.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

I think this thread presents an opportunity to discern between direct and indirect realism. Derrick’s argument pretends to prove the time lag of phenomenal world in relation to noumenal world, whereas refuting of the argument goes in favor of direct realism. I feel myself to be a direct realist simply because I do not see any way to step on the outside from the appearance. To be is to be observed or, mutatis mutandis: to be is to appear to be. The subject of neurology remains within the realm of appearance. Our brain tissue is nothing but a picturesque ensemble of qualia. Facade is everything.

Well, I think modern physics is very much in favor of direct realism too. Basic concepts of common sense physics are in upheaval. Velocity has nothing to do anymore with covering some distance for certain period of time. Space accelerates objects, acceleration turns energy into mass. Symmetry overrides causal history and identity of particles. Ignorance causes interference patterns of the waves of appearing. The merrier the better. This kind of physics until recently has been applicable only in the land of dreams and to the journeys of shamans and other  psychonauts. However, the modern physics is telling us that even fully awake we are still participating in one big dream of Nature. I still think there is a dreamer who dreams that Grand Dream. You can call it the ultimate Big Brain, or the Gad, or whatever. I like to think it was this dreamer that Plato had in mind when in Timaeus mentioned the soul of the world.

Indirect realists, like Steven Lehar, for example, situate the „Grand Illusion“ in individual human brains and end up with at least one grand illusion per one human skull amidst some allegedly scientifically coherent and rather materialistic noumenal world. Direct realism is unscientific because it bravely proclaims appearance to be the only reality while the science should be exclusively about the appearing of that reality. I would say that direct realism is nothing more unscientific than modern physics. Metaphysical reality is still there but it is reduced to the mechanism of appearing of reality.

To answer what I think about all questions and challenges that you have posted, I would need to explain my original theory of colors and that is certainly out of scope of this communication. I would argue that all qualia are colors. There is no difference between visual colors or tactile or audio colors. All qualia are located in 4D perspective. Particularly interesting to me is the color of balance. However, my favorite is certainly the color of outsideness. Appearing is on the outside and the outsideness is appearing. What paint, or what pigment is used to depict the extension of outsideness?

I have tried to start new thread about this color but my proposal was rejected, perhaps because of my funny English.


2011-05-23
The time-lag argument for the representational theory of perception
Steve Lehar: "You put all that together into a cast-iron irrefutable case, and the world of academia will simply ignore you and your argument as if they simply did not exist. This is a paradigmatic issue -- like religious belief. You can't convince them with logic and reason and irrefutable evidence, because they simply won't believe it. Believe me! I've spent an academic lifetime of being ignored! They will have to die and be replaced by a fresh new generation before the idea will ever take hold."

I am generally in agreement with much of the content of your links with a minor difference about the location and substrate of conscious experience. The problem here is that if we live by a scientific approach we must die by it. We need to propose some "killer" experiments!

Aleksandar
: "All qualia are located in 4D perspective. Particularly interesting to me is the color of balance. However, my favorite is certainly the color of outsideness."

We still need to debate where conscious experience is to be found in the world, I say its in the brain and have given several arguments for this viewpoint, I do not believe that you need to explain your theory of vision to refute my arguments because they were independent of any particular theory of how conscious experience itself occurs. Furthermore there is a problem with your approach as an argument for Direct versus Indirect realism becuase it cannot distinguish between an em field in the brain or an em field in the world at large. Both Steve Lehar and myself would admit of the possibility of an em substrate for the phenomenal. As an example, the firing of neurons creates a localised low frequency em field that could enter into the sorts of combinations that are typical of colour theory. So an em theory would not resolve our debate.

You suggest that physics leans towards Direct Realism but I disagree, physics has not proven Direct Realism at all. Decoherence Theory suggests that there is an infinity of entangled, classical environments and some physicists assume that we are machines trapped in one of these environmental states. If there were a God He would see this infinity of universes (the multiverse) but we cannot. The flaw in decoherence theory when applied to mind is that mind is largely epiphenomenal. It is not tightly bound to the environment.  Suppose that an observer were completely epiphenomenal (unable to affect the environment), such an observer could in principle switch from one entangled environment to another, what would that observer observe? The observer would observe a classical environment wherever it switched. Events would all appear to be correctly determined by physical laws.  The reason this would be the case is that each entangled "environment" is an entire set of consistent events stretching back into history.  If mind were wholly epiphenomenal we might be like this observer, a bit like the God above, able to move to any universe in the multiverse.  However, mind is not wholly epiphenomenal, for instance, I can describe the form of my mind (see Time and Conscious Experience) and this requires a physical connection. If mind is a system that is loosely coupled to the brain, like for instance a low frequency em field (or various other fields), then the universe would consist of an environment that contains conscious entities that might have a limited ability to change their universe of residence.  So, to prove that we are machines in a fully determined brain in a classical environment a physical theorist must prove that the mind is not largely epiphenomenal.  It is ironic that prior to the quantum age Direct Realists used to rely upon arguments that the mind is epiphenomenal, a "ghost in the machine", and now they must rely upon the opposite argument!


2011-05-23
The time-lag argument for the representational theory of perception

Milencovic >>>
Indirect realists, like Steven Lehar, for example, situate the "Grand Illusion" in individual human brains and end up with at least one grand illusion per one human skull amidst some allegedly scientifically coherent and rather materialistic noumenal world.

<<< Milencovic


And I have solid irrefutable proof that that is the case, based on the observed properties of visual experience, in particular phenomenal perspective.


http://cns-alumni.bu.edu/~slehar/epist/epist6.html



The fact that the world of experience is curved into a spherical shape, centered on each observer's egocentric point, is proof that that experience is private to each individual, as explained in these frames from my Cartoon Epistemology.


http://cns-alumni.bu.edu/~slehar/cartoonepist/cartoonepist15.html

...
http://cns-alumni.bu.edu/~slehar/cartoonepist/cartoonepist19.html



The only way to deny that is to follow the example of Eric Schwitzgebel, who denies that he sees any curvature in his experience whatsoever! But then he would have difficulty explaining the results of THIS experiment:


http://cns-alumni.bu.edu/~slehar/hallway/hallway.html



But it seems that all the evidence in the world won't convince those who refuse to accept it, because they BEGIN with the assumption that perception is direct, and their arguments are merely a rationalization of a belief that they see as self-evident. So this whole debate is futile, it just goes round and round in crazy circles just as I depicted in the Cartoon Epistemology.


This is just like the debate between Ptolomy's terra-centric cosmos and Gallileo's helio-centric cosmos, or the debate with the "Vitalists" of the last century who insisted that life is something more than mere biochemistry. Although all the facts were in favor of the more rational view, nobody was ever convinced, the older generation had to die off for the new generation to realize the truth of the rational view.


We are all wasting our breath on an issue that is so obvious it is absurd!









2011-05-29
The time-lag argument for the representational theory of perception
Reply to Steven Lehar
Hi Steve,

I was looking at your experiment on the form of a hallway.  The question arises as to why the 3D perspective model was more convincing than the 2D perspective model.  You might be interested in my short article Time and Depth which attempts to tackle this very problem.

2011-05-29
The time-lag argument for the representational theory of perception


 SEEING THINGS MY WAY
 (The record shows
 I took the blows
 and saw it my way.)

JUD EVANS

Can the little man inside see me Daddy? A camera "sees" (gathers datergic information) about that part of the world towards which it is pointed. There is only "one world" and no interior or inner world of the brain-pan and an exterior world of the environment. Body and "Mind " [sic] don't ride a transcendental tandem. "Nature" does not have time for paranormal parlour games like "cosciousness" and Qualia." Being like a bat equals being a bat.  Such imaginings are primitive human abstractions that do not exist. Only the earth-world and the meat-brained human abstractors together with that which surrounds them exist.
 
We exist "out there" [sic] in the world like any other entity in the world. The embrained body (or embodied brain if you prefer) sees the world through the aqueous humor filled lenses of the brain - the nominata of the English word eyes There are photosensitive cells -  but there is no such thing as the reification, " photosensitivity. " Nor is there a Cartesian music hall of the mind, nor a  Heideggerian psychic viewing suite situated in the visual cortex, where Daseinic truth-dodgers twiddle ontological twizzle-sticks which trigger occult immateriality pulses called: "private conscious experience waves" which suspire from the neurological representational meaty bits like metaphysical marsh gas or the non-question og "being."

Many people merely replace the reification "homunculus" with the reification "the mind" or "private conscious experience," or some other curious neologic phrasing. Surely, after bouncing off some object, the photonic datergy (compare matergy) impacting the outer brain (the eyes) energises the neuro-synapses of the permutational brain via a part of the central nervous system called the optic nerves, to fire and form specialised transient patterned neuronal matergy clusters (energised matter).) in the primary visual cortex which is composed of  extractable brain-meat - once considered a delicacy by cannibals and not some modern version of an imaginary metaphysical mental manikin which would not fatten a blue-bottle -  never mind a hungry Korowain (one of very few tribes still believed to eat human flesh as a cultural practice.)

If an observer views the changing matergic image of a digital camera as it is swung around, the casually roaming causal lens triggers the modifiable modal camera chip to exist in a differing causal existential mode from nano-second to nano-second. Light impacts an array of light-sensitive cells that release a tiny matergic charge in each activated cell producing pixelated constellates.

Similarly (but this time organo-matergically) the human eye encounters changing light sources and triggers electro-chemical synapsal ignition sequences which vary the existential modality of the neuronal patterning  reticulum activating system or structured neurological network of the energised brain-meat at that particular moment in time.

The changing matergic brain is comprehended holistically by the perceiving, experientially envisioning entity - the organically totalised human animal - not some reificative homuncula stand-in called  "experiental- consciousness."

The wild construables positing the "existence" of such conceptual intangibles as inhabiting the human brain-pan are little much removed from the belief of our primitive forebears that spirits resided in rivers and trees, or the Trobriand Islander who believed that the "soul" of his grandfather had taken up residence in and empty coca-cola bottle which had been washed ashore on the beach.

The environment is "seen" by earthly, exterior-based, sensorially equipped human beings that exist in the world in the same way that the objects they observe around them. It is the meaty experientially conscious human who sees a house or a hat-pin. In other words, as a digital camera EXISTS differently as it sensors are spatially re-situated by the human photographer, so the human body-brain exists differently as its sensorial brain-extensions (eyes) switch from object to object.

Compare an electronic calculator, which does not actually "calculate" anything at all. It simply lies in your hand as you change the way it exists in response to the prodding of the causally connective input buttons. It is the human calculator who pushes the calculator buttons and benefits from the superior rapidity of the calculative electronic chip.
 
The difference between a light responsive digital camera, a prod-responsive calculator and a sensorialised light responsive human (and many other sentient creatures) is that the camera and the calculator are sensorially unaware of their own changes and are entirely dependant on the sensorially restricted parameters factored in by the human designer. The human is (has evolved) and has been phylogenetically programmed to remember and respond to the changing environment for reasons of survival and procreation. The whole human sensorium is one integrated survivalist feed-back mechanism with not a single occult hypostatisation (whether scientific or transcendentalistic  that goes dualistically bump-diddy-bump-in-the-night  in sight. It is Stockholm bound for the lucky Nobel Prize-winner who proves otherwise.

Best,
http://evans-experientialism.freewebspace.com/study.htm
Jud Evans.
The Athenaeum Library of Philosophy



2011-05-31
The time-lag argument for the representational theory of perception

TIME LAG? SORRY – NO SUCH THING.

Jud:
I thought the diagrammatic depiction of time-lag was cool, but  "Time"  does not exist. Thus there are no such thing as the useful fiction: *past events.* There is no so-called *time-lag.* The body-brain becomes aware of, acknowledges or registers (not represents or re-represents) received sensorial information. There is no time-lag for neither *time* nor *its lag* exists. The individual existential occurrences betwixt associated (co-catenulate) causal objects never take place concurrently or instantaneously, because ll objects ALWAYS occupy different spatial positions when an exchange of matergy takes place.

No two objects in the cosmos are EXACTLY the same. No two objects emit or absorb matergy at a shared causative coefficient even though they may seem very similar to the human observer. If such WAS the case there would not BE two causal objects - but one such causal object. No object in the cosmos involved in a causative impingement-relationship with another object changes at EXACTLY at and within the same existential modalic interstice in the continuum. What exists is *that which is timed* by humans - in this case on the one hand a camera's electrified gaseous matergy luminously discharging as xenon gas contained in a tube and on the other hand an embrained human who has evolved to register changing causal objects (such as flash cameras and yapping dogs) exterior to and not belonging to the contents of the epidermal envelope within which its fleshy human holism is contained.

The fact that the gas induced datergic signal, (at first photonic and then latterly chemico-electrical) reaches the brain in accord with the useful sun-based mensural fiction known as: "100 milliseconds" after the gas event does not mean that a *flash* occurred at a *scene* for *flashes* do not exist and neither do *scenes*- only that which flashes exists in a certain spatial position in the world (i. e. the camera and its electronically ignited xenon gas) .
 
The brain's awareness of the fluorescing gas via the concatenational reception of the datergy following the light-emitting event would not different as a neurological event if it were physically/physiologically possible to transact the datergy instantaneously. But instantaneity is cosmically impossible, for if it were to be the case - the cosmos would not exist in the first place and I would not be here to explain to you why everything does not happen at once.

It is not necessary to create and  introduce clock-dependent transcendental or  dualistic explanations  like mind or even worse qualia to explain perfectly natural non-metaphysical occurrences.

Best,

Jud Evans


2011-06-07
The time-lag argument for the representational theory of perception
Hi JKW,
I read your article Time and Depth, and must disagree fundamentally.

Although admittedly the Necker cube experience appears partially 2-D and partially 3-D, you cannot convince me that I don't experience it as a solid volumetric experience, with bars in the foreground separated from bars in the background by a volume of empty space, not just a fluctuation in time. But whatever you see for the Necker cube, you can hardly deny that our ordinary everyday experience of the world around us is a solid volumetric experience! To claim that experience is anything other than as it is experienced to be, is a contradiction in terms. And I experience the world around me as a solid volumetric spatial experience, like a theater set, or museum diorama. It suggests a computational mechanism like this:

http://cns-alumni.bu.edu/~slehar/webstuff/bubw3/bubw3.html#compmech


to account for the observed properties of experience. While it is true that we do not experience the hidden rear surfaces of perceived objects, we do experience their exposed front faces as sloping in depth, and embedded in a volumetric spatial manifold. That is at least *my* experience!

2011-06-07
The time-lag argument for the representational theory of perception
SEEING THINGS MY WAY

Can the little man in your head ever learn to see the bounding surface of his finite bubble of experience? When I blink my eyes closed, the world disappears, and when I blink open again, it reappears again in all its color and glory. Where did it go while my eyes were closed? Did it cease to exist? Because it certainly disappeared from *my* experience while my eyes were closed. The part of the world that disappears when I close my eyes, is my experience of the world, and that experience is causally dependent on the state of my eyelids, whether they are open or closed.

The after-image from a camera flash appears floating in empty space before us. Why is it not experienced on the retina, at the back of our eyeball? And why is our retinal after-image *not* inverted by the lens, as we know it to be in our real eyeball? How did that image get re-inverted to appear right-side-up again projected out of our eyeball into the world?

But the biggest clue of all is the prominent warp of the bubble-world. Have ye not seen the dome of the night sky arching overhead for all the world like the dome of a planetarium? Have you not seen the railway tracks converge to the vanishing point on the horizon? And did you turn and see them converging also in the opposite direction too?

How can a man see all these things and still not see the finite boundaries of his spherical bubble of perceptual experience? He stares at the dome and thinks he is seeing an infinite void. He stares at the horizon and believes the tracks to be straight and parallel and equidistant all the way out to infinity, which he can see with his naked eye at the point where the tracks meet. And it is well short of infinity.

"I don't see anything converging. Things in the distance don't look smaller!" Yeah, and you can see all the way to infinity never realizing that you never even saw beyond the confines of your own skull. Man of science whose knowledge projects out over the entire infinite universe, so seems it him, unbeknownst, knows only the universe within. Im inneren is ein Universum auch.








2011-06-07
The time-lag argument for the representational theory of perception
Reply to George Evans
Jud, you declare that there is no such thing as your view containing this screen.  Suppose there were such a thing in my mind and I was able to find that it had concurrent and simultaneous parts and hence was a "space" and furthermore was able to point to experiments that showed that this space was a projective space, probably in my brain.  Would you be happy for me to pursue this as a scientific enquiry?  I know you cannot "see" this writing but maybe your processors can give an answer.

2011-06-07
The time-lag argument for the representational theory of perception

A representation, by definition, is always a synthesis of a natural phenomenon and any natural phenomenon by definition, is complex and not definable.

If you represent time (and time gap) with an hypothetical fixed value you will always encounter an explanatory problem, the same problem that you would encounter by giving a fixed value of money in a market transaction.

To buy goods you must have money and money at the time of the transaction must have a fixed value, there is no doubt about it, but it would be wrong to consider that the value of money is fixed, in fact, the value is always determined by the “balance” of the various transaction made in the past, that are made in the present and including also the future expectancy. (if not the market would have already collapsed or will collapse in the future)

If you agree that only a complex circular process is at the base of the value of  money, you could agree with me that the same complex circular process might apply also to the value of time, a value that will include a complex combination of past, present and future.

This should answer your fourth point, it is true that a vision must have a time gap, and that any vision you experience might be situated in the past, but so is the value of money, a “past” value that your transaction and the transaction of all other participant of the market will change, nothing is fixed o settled forever, and it should include time.

c. morozzo


2011-06-08
The time-lag argument for the representational theory of perception

Hello JWK,

There are no such things as a *views, minds, space, projective space.* Such primitive notions are useful fictions to temporally fill in the awkward gaps in the ontological understanding for folk-scientists, or when people are engaged in fleeting conversations in bars or at bus stops, or in railway waiting-rooms when the avoidance of periphrasis or ambage usually governs the exchange of datergy betwixt humans in a hurry. Such reifications are useful bookmarks pending the day when the curtain of misunderstanding is raised and the real scientific explanation of what we presently call dark matter becomes public knowledge, which in my opinion will provide an important key to the T.O.E.

Words such as *mind* (O.Eng. "memory, thinking, intention,") are redolent of terms like *phlogiston* a 17th century attempt to explain oxidation processes, or *witchcraft,*  terms which were once used historically in all seriousness, but have since become examples of scientific jocularities and occultist nescience respectively.

What exist (and I have no need to provide evidence – simply look around you) are visually enabled humans, of which you and I are examples. Sensorially humans can see, (I can certainly *see* your writing – it is my *seeing* or *sight* that does not exist). The *ability to see* does not exist either in tandem or as some kind of dualistic bolt-on in addition to *the seeing human.* Note the use of the prepositional adjective *seeing* existentially modifies subject nouns or pronouns alike.

To write: *The seeing human* makes it plain that (like most animals) the human exists as an ontological monism -   as a seeing organism and that it is the existing human that can be found in the world and not his (gerundialised or reified* spiritualistic doppelganger *called *seeing* invisibly hunkered down within the bony carapace of the skull too.

Equally the human exists with a specially evolved sensorialised fleshy organ – the thinking brain – but the reificatives: *thinking, mathematising, communicating and remembering* do not exist any more than the *seeing* or *viewing*  *perspectivally observing,* or *baking raspbery tarts.* (though the baker of such tarts and their ingredients undoubtably exist.)

As far as there existing a *thing* which you apparently believe may be lurking in your cranium called: *mind* (and what you mean by the word *thing* only you know the answer to that,) I look forward to reading your scientific enquiry in to this particular and rather peculiar metaphysical mediaevalism. The dictionary provides an amusing compendium of fictive ontological fun such as:

*A special situation, an action, a special abstraction, a vaguely specified concern, an event, a statement regarded as an object, An entity that is not named specifically, an artefact, a separate and self-contained entity.*I would certainly be happy for you to pursue this as a scientific enquiry? I respect you as an intelligent and very creative thinker. I think your drawings are very innovative and educational. But I doubt very much if your approach is scientific in an ontological sense, though your observations no doubt make sense to others who have been similarly imprinted in infancy with the usual evanescent ontological dualism, which vanishes like vapour when exposed to rigorous ontological cross-examination.

you wrote:

*I know you cannot "see" this writing but maybe your processors can give an answer.*

Like most humans I have neurological meaty-bits which can be described as sensors and processors which enable me to see – it is the *seeing*, the *perspectivalism* and the *neurological processing* which nobody on earth (or anywhere else) *has.*

Why? Because, like your imaginary "lines of perspective" disappearing into *infinity* (whatever that is supposed to be) such reificative Neurathean boats or bootstraps do not exist.

As for the imaginatum *projective space,* such ontological shibboleths simply do not exist. What exist are spatially situated objects (houses, trees, lampposts, etc) which seeing human animals view in terms of the near ones existing as larger than those farther away which are perceived as perspectivally diminishing is size.

If human animals did not view objects of the environment this way we would not have evolved to be the organisms we are and you would not be reading this. If humans had been the victims of a rib-tickling evolutionary handicap or glitch (a physical, physiological, optical and ophthalmic impossibility in any case) of seeing the surrounding environment in terms of near and far away objects all existing at the same size - it would have led to the elimination of such species millennia ago.

Best,

Jud.
The Athenaeum Library of Philosophy


2011-06-08
The time-lag argument for the representational theory of perception
Reply to Steven Lehar
"When She Shuts Her Eyes, It's Night."

Stephen Lehar writes:

Can the little man in your head ever learn to see the bounding surface of his finite bubble of experience? When I blink my eyes closed, the world disappears, and when I blink open again, it reappears again in all its color and glory. Where did it go while my eyes were closed? Did it cease to exist? Because it certainly disappeared from my experience while my eyes were closed. The part of the world that disappears when .

Jud:

Captain Cat:  "There goes Mrs Twenty-Three, important, the sun gets up and goes down in her dewlap, when she shuts her eyes, it's night."

Under Milk Wood.Dylan Thomas.Sorry to have to break the sad news...but... there is no... little man in rhombencephalonic residence. No room at the apparitional inn for homely homuncular housing in the hindbrain. The thinking  brain-meat is too tightly packed, even for tiny preformative transcendentalist tenants of the telencephalonic Cartesian theatre-in-the-round. As for disappearing experiential trouble-bubbles, next time you close your eyes – close them as you stand in front of an approaching ten ton truck. You will find that it is not only your experiential bubble that bursts -  your epidermal envelope will pop and lose its contents too.  Of course I do not really want to lose you in this way - it's just my playful Liverpool (scouse) humour.

Best,

Jud.
The Athenaeum Library of Philosophy.


 


2011-06-10
The time-lag argument for the representational theory of perception
Reply to Steven Lehar
Steven, we both agree that "we do experience their exposed front faces". This one-sided aspect to objects is equivalent to saying that the objects are not like pixels but have a property of directedness.  Directedness is a synonym for "one-sided".  But what is "directedness"?  It is commonly described as a direction of travel of a probe of some sort. It involves movement. Just inserting a spatial displacement between a viewing point and the object does not provide a direction, it just provides space.

A directed element is composed of both space and time but actually moving pixels from one point in space to another does not achieve anything more than replicating an object. Moving pixels is a displacement and does not achieve the "directedness" that confronts us in the view that is our experience.

 It is this conundrum of how a "view" can be created that has objects that are both separated from a viewing point and one-sided without any actual motion of matter that was tackled by Aristotle and Descartes. Aristotle proposed that there was some sort of geometric point that involved both space and time that permitted our experience whilst Descartes simply united the data in a "view" with a point-like, supernatural soul.

Nowadays Aristotle's solution makes a great deal of sense because we know that the geometry of the universe is four dimensional with one of the dimensions being a curious "negative dimension" called dimensional time.  If distances are measured relative to the centre point of the view (our experience) then the equation:

s^2 = x^2 + y^2 + z^2 - (ct)^2

describes a set of vectors (s) that are separated in space and time and pointing along a direction defined by the time axis.  The "null vector"

0 = x^2 + y^2 + z^2 - (ct)^2

is a set of directed points that are no distance in spacetime from a centre point but separated in both space and time from each other.  The null vector corresponds to the path taken by a photon but, being a path, it is there even when a photon is not traversing it.  The equation for the null vectors satisfies the problem of the separation of the content of a view from the viewing point, the one-sidedness of objects in the view and does not require the pixels in a view to by piled up together in a central point - all that happens is that the separation between the parts of the view disappears in the direction of the centre point in spacetime but the parts stay where they are in space and time.

Perhaps my article was a bit misleading, overstressing the role of time, when it is spacetime that provides the directedness or one-sidedness in the view.

Your paper seems to advance our understanding of how the content of the view is created but it does not account for the simultaneity of perception (perception involves concurrent objects) or the directedness of perception.

2011-06-10
The time-lag argument for the representational theory of perception
Reply to George Evans
Jud, you put forward an interesting line of invective.  You flatly deny that my experience could contain space and time but I can see little justification for this denial.  Please define your understanding of the terms "space" and "time" then describe how these do not exist in your experience.

2011-06-11
The time-lag argument for the representational theory of perception

RETRONYMIC UPDATING

Dear JWK,

Although I enjoy it, writing to you is very difficult because you speak (possibly live) in a world of abstraction cleverly and interestingly rationalised as empiricism. You are (like practically everybody else) misled by ancient verbal forms imprinted upon your reticulate neural nets during the period of your  familial  upbringing and socialisation and have internalised the "fact" that simply because some noun has an indicative or deictic role, there must be some *thing* to which it refers or semiotically points out as an actual denotatum.

One cannot point to existential modes of a human neurological reticulum (although one may think that such is the case) because *existential modes* do not exist to be indicated  *action* does not exist only the actant. Unless one indicates an object of some kind one is indicating>    !   

There is no *activity* existing in the brain, nor, psyche, mind, spirit, soul, energy, dynamic nor any other spiritist fictional product of our imaginations, just the fleshy, electrified, chemicalised, thinking, active or activated brainmeat.

In other words, though fascinating and intellectually stimulating the nominatives you employ (for the most part) consist of non-referential reificative riddle me ree (from my POV) urgently in need of retronymic updating because existing terms like *time* and *experience have become inadequate for science because they do not refer to anything real (*experience => *experiencer* and *time => *that which is timed* instead.)
 
If Einstein had replaced the reification *relativity* with *relative cosmic objects* it would have been much nearer to the heavenly facts of the matter. Though admittedly *The Theory of Relative Cosmic Objects* does not have the same snappy sound as  *The Theory of Relativity.*

I think and live in a real, entiative *thought less – rather than entitively *thought* – ful) world of flesh and blood thinkers (*thought* being yet another ontological nursery word) consisting of material concrecity, a domain of ever changing material entities, never *being* (in the ontologically grotesque Heideggerian meaning of the term)  but incessantly *becoming* causal objects which exist in the only way they can exist, as conglomerated communities of interactive individuates impinging upon other coalescences. It is the more obvious impingements that humans have singled out as so called *events* around which they have constructed the useful fiction called *time.* I refer of course to the turning, moving earth elliptical orbiting the centrally spatialised sun at an average distance of about 150 million kilometers, every 365.256363 mean solar days. Providing an apparent *movement* of the Sun to a human observer with respect to the stars at a rate of about 1°/day (or a Sun or Moon diameter every 12 hours.) So much for the ersatz (artificial, but in this case organisationally and mensurally useful) chronological abstraction *time.*

It is a world that does not recognize abstraction as serious items of philosophy or science, but as being no more than useful fictions or handy ways of talking about …blank… I leave a …blank… and insert the word "blank" because I do not wish to employ the word *nothing* in case I fall into the trap of appearing to be referring to something called nothing – which neither exists or does not exist. Such is the way in which I regard other *nothing words* like *time, space, mind, experience movement, action* or all the rest of the useful fictions that men prefer to use as an alternative to getting down to serious onto-semantic brass tacks.

I appreciate you may have difficulty in understanding what I am trying to say and for that I sincerely apologise. Like many others I am grappling with inherited forms of communication which are ontologically attenuated with the virus of duality. However, unlike Wittgenstein I am unwilling to remain stumm or ascend into a domain of zero-comunication then pull up the ladder and sulk.

Best,

Jud.

Athenaeum Library of Philosophy


2011-06-30
The time-lag argument for the representational theory of perception
Hi JWK,
>>>>
Steven, we both agree that "we do experience their exposed front faces". This one-sided aspect to objects is equivalent to saying that the objects are not like pixels but have a property of directedness.  Directedness is a synonym for "one-sided".  But what is "directedness"?  It is commonly described as a direction of travel of a probe of some sort. It involves movement. Just inserting a spatial displacement between a viewing point and the object does not provide a direction, it just provides space. 

<<<<


There is no movement necessary for directedness in experience.


I explain this in detail in my book The Boundaries of Human Knowledge Chapter 3 The Experience of Self and Non-Self, that the directedness of experience is illusory.


Take a look at Figure 2.2 that depicts the experience of a tomato viewed from a viewpoint.
Whether or not that eyeball is part of the picture, the tomato still directs its colored surface in that direction. The experience of the tomato is located at the location it is experienced to occupy.


It is the same basic principle as seen in this radar scope image as shown in Figure 3.4 that also shows directedness towards a central viewpoint as if the whole scene was being viewed from a viewpoint at the center of the radar screen. As I say in the text:


>>>>

Is the special viewpoint apparent in the radar image real or illusory? It is real in the 

external world, where radar signals are transmitted from a particular location, and 

therefore the echoes from those signals replicate that veridical pattern of central 

illumination. In the internal world of the radar scope on the other hand there is 

nothing special going on at the center of the glass screen, except for the fact that 

that point happens to represent the position of the radar dish itself in the external 

world. But the center of the scope does not “view” the rest of the pattern on the 

screen, the center of the scope is merely part of the space represented by the 

screen, and is expressed in that representation in the same manner as every 

other part of the represented space. In exactly analogous manner, we observe a 

special point in phenomenal space towards which all modal surfaces in the world 

are oriented, and that is a veridical manifestation of the true external situation 

where the surrounding world is indeed viewed from a particular viewpoint by our 

eyes. But in the phenomenal world, the world of our visual experience, there is 

nothing special at all about the center of that space. The egocentric point is not 

the viewer of the rest of the scene around it, but rather the egocentric point is the 

point in perceived space that represents the perceived location of the ego, which 

serves as the origin of the spherically-symmetric world of perceptual experience. 

The illusion of viewing our experience from an egocentric point was already 

dispelled by the Buddhist realization that the world of experience that appears to 

surround us is actually part and parcel of our own self. Despite appearances to the 

contrary, we do not view the dome of the blue sky ‘out there’ from this central 

location ‘in here’, but rather the experience of the sky is a spatial structure that 

appears in our experience at the location where we experience it to be located. It 

simply exists out there as part of our experience. The only reason why it 

disappears from its experienced location when we lower our eyelids like a curtain 

between the blue sky and our egocentric point, is not because the egocentric point 

is looking outward at the perceived sky through the windows of our eyes, as it 

appears naively, but because the phenomenal experience of vision reflects the 

causal structure of the real external situation, where our physical eyes do indeed 

view the physical world through our physical eyes. Significantly, mental images, 

dreams, and hallucinations can occur with eyes closed, and when they do so, they 

appear in the volumetric space beyond the closed lids unhindered by the blockage 

posed by those lids. So the illusion of viewing our experience from a particular 

point is both real and illusory; it is real in the external world of reality of which our 

experience is an imperfect replica, but it is illusory in the internal representation 

itself where experience is painted or plotted at the location where the 

corresponding external objects and surfaces are perceived to be located. 


<<<<

If you really want to understand this concept, I urge you to read that whole chapter, it may take a bit to sink in. It is a very important philosophical point that has led to endless confusion over the ages.


  Steve








2011-10-06
The time-lag argument for the representational theory of perception
Reply to George Evans
Here is an interesting addition to the Time Lag Debate, a NEGATIVE time lag in which, when subjects are trained to press a button to create an event the timings between the button press and the event can be varied so that the subjects perceive the event to occur before the press of the button!

How would a Direct Realist explain this?

See SENSORIMOTOR ADAPTATION TO VIOLATIONS OF TEMPORAL CONTIGUITY
Douglas W. Cunningham,1,2 Vincent A. Billock,2 and Brian H. Tsou3
Psychological Science VOL. 12, NO. 6, NOVEMBER 2001






2011-12-04
The time-lag argument for the representational theory of perception
Dear JWK,

Sincere apologies for not responding to this post a lot earlier. The fact is I have only just noticed it, for during the period you wrote it the local village telephone exchange conked out and nobody could get landline access to the outside work (other than by using mobile phone or hang-gliding to the next village.)

I would respond to  your  question this way. But first I am anything but a *Direct Realist* who agonises over the epistemological question of whether the environment we see around us is the real world itself or merely an internally perceptualised simulate of that world generated by neural processes or a neurological lego-set in our brain whereby our conscious experience is an internal representation, a miniature virtual-reality replica of the world,etc.

As someone who believes that the concept of *time* is nothing more than a utile sham or useful fiction (handy for railway stationmasters, the man who pulls the whistle on the factory whistle at the start of  a shiftat the chocolate factory and  the local church bell-ringers, for me the metaphysical paraphernalia of the time lag experiment is philosophically worthless. 

 *Events* do not exist. It is only the objects which sequentially (concatenationally)  impinge upon another (and thus are themselves impinged upon) that exist. The objects involved in this particular onto-hermeneutical harlequinade are the mistakenly perceptive human button-pushers,  the buttons, the wire and the matergy that flows through them,etc. Of course, the wretched   time wasting deceivers who set up such experiments at the taxpayers expense are the real guilty ones.  As to what a *Direct Realist* would think of such shameful conspiratorial confidence tricks with the continuum I shudder to contemplate. <smile>

Best wishes,

Jud


2011-12-27
The time-lag argument for the representational theory of perception
Reply to Jud Evans
These "objects which sequentially (concatenationally)  impinge upon another (and thus are themselves impinged upon) that exist" appear to have an ordering, a sequence, according to your statement.  Any ordered set can be subjected to a high level of measurement and comparison (a ratio level in this case). So, by your own definition we can discover the relations within and between sets.  We can do science.

Science shows that there are at least two sorts of "time": dimensional time and the time of change.  "Dimensional time" is related to the spatial measurements of high speed objects and allows us to calculate the exact values of magnetic fields, kinetic energy, gravity etc.  You may not agree that this exists, if so, please suggest an experiment to demonstrate this assertion.  Science also points to a time that is related to the evolution of physical systems, this has a particular direction and is related to thermodynamics and quantum theory.