This article compares the three frameworks for theories of consciousness that are taken most seriously by neuroscientists, the view that consciousness is a biological state of the brain, the global workspace perspective and an account in terms of higher order states. The comparison features the “explanatory gap” (Nagel, 1974; Levine, 1983) the fact that we have no idea why the neural basis of an experience is the neural basis of that experience rather than another experience or no experience at all. (...) It is argued that the biological framework handles the explanatory gap better than the global workspace of higher order views. The article does not discuss quantum theories or “panpsychist” accounts according to which consciousness is a feature of the smallest particles of inorganic matter (Chalmers, 1996; Rosenberg, 2004). Nor does it discuss the “representationist” proposals (Tye, 2000; Byrne, 2001a) that are popular among philosophers but not neuroscientists. (shrink)
Such claims are part 0f a viewpoint according t0 which mental images represent in thc manner of pictures. It is very natural t0 think that such claims are confused or nonsensical. One of my purposes here is a limited dcfcnsc of this supposedly confused doctrine, especially against its chief cognitive science rival. But this..
Consciousness is a mongrel concept: there are a number of very different "consciousnesses". Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state.
There are two broad classes of empirical theories of consciousness, which I will call the biological and the functional. The biological approach is based on empirical correlations between experience and the brain. For example, there is a great deal of evidence that the neural correlate of visual experience is activity in a set of occipetotemporal pathways, with special emphasis on the infero-temporal cortex. The functionalist approach is a successor of behaviorism, the view that mentality can be seen as tendencies to (...) emit certain behavioral outputs given certain sensory inputs. The trouble with behaviorism is that it did not allow that mental states were causes and effects, but functionalists do allow this. They characterize consciousness in terms of its causal role: the causal influence on it from inputs and other mental states, and its causal efficacy with respect to other mental states and behavior. The central idea of functionalism is a proposal about the concept of consciousness, but scientific functionalists have filled the view in with empirical details—the idea is that a representation is conscious if it is broadcast in a global neuronal workspace. (See the article by Dehaene in Dehaene, 2001.) The functional approach says consciousness is a role, whereas the biological approach says consciousness is a realizer of that role. For example, one could take solubility to be a role—dissolving in certain circumstances—or, as with the biological view of consciousness, the physico-chemical configuration that has that role. The.. (shrink)
Often when there is no attention to an object, there is no conscious perception of it either, leading some to conclude that conscious perception is an attentional phenomenon. There is a well-known perceptual phenomenon—visuo-spatial crowding, in which objects are too closely packed for attention to single out one of them. This article argues that there is a variant of crowding—what I call ‘‘identity-crowding’’—in which one can consciously see a thing despite failure of attention to it. This conclusion, together with new (...) evidence that attention to an object occurs in unconscious perception, suggests there may be a double dissociation between conscious perception of an object and attention to that object, constraining the extent to which consciousness can be constitutively attentional. The argument appeals to a comparison between the minimal resolution (or ‘‘grain’’) of object-attention and object-seeing. (shrink)
Discussion of J. Kevin O’Regan’s “Why Red Doesn’t Sound Like a Bell: Understanding the Feel of Consciousness” Content Type Journal Article Pages 1-20 DOI 10.1007/s13164-012-0090-7 Authors J. Kevin O’Regan, Laboratoire Psychologie de la Perception, CNRS - Université Paris Descartes, Centre Biomédical des Saints Pères, 45 rue des Sts Pères, 75270 Paris cedex 06, France Ned Block, Departments of Philosophy, Psychology and Center for Neural Science, New York University, 5 Washington Place, New York, NY 10003, USA Journal Review of Philosophy and (...) Psychology Online ISSN 1878-5166 Print ISSN 1878-5158. (shrink)
One of the most important issues concerning the foundations ofconscious perception centerson thequestion of whether perceptual consciousness is rich or sparse. The overflow argument uses a form of ‘iconic memory’ toarguethatperceptual consciousnessisricher (i.e.,has a higher capacity) than cognitive access: when observing a complex scene we are conscious of more than we can report or think about. Recently, the overflow argumenthas been challenged both empirically and conceptually. This paper reviews the controversy, arguing that proponents of sparse perception are committed to the (...) postulation of (i) a peculiar kind of generic conscious representation that has no independent rationale and (ii) an unmotivated form of unconscious representation that in some cases conflicts with what we know about unconscious representation. (shrink)
The Anna Karenina Theory says: all conscious states are alike; each unconscious state is unconscious in its own way. This note argues that many components have to function properly to produce consciousness, but failure in any one of many different ones can yield an unconscious state in different ways. In that sense the Anna Karenina theory is true. But in another respect it is false: kinds of unconsciousness depend on kinds of consciousness.
The higher order approach to consciousness attempts to build a theory of consciousness from the insight that a conscious state is one that the subject is conscious of. There is a well-known objection1 to the higher order approach, a version of which is fatal. Proponents of the higher order approach have realized that the objection is significant. They have dealt with it via what David Rosenthal calls a “retreat” (2005b, p. 179) but that retreat fails to solve the problem.
Much of recent philosophy of perception is oriented towards accounting for the phenomenal character of perception—what it is like to perceive—in a non-mentalistic way—that is, without appealing to mental objects or mental qualities. In opposition to such views, I claim that the phenomenal character of perception of a red round object cannot be explained by or reduced to direct awareness of the object, its redness and roundness—or representation of such objects and qualities. Qualities of perception that are not captured by (...) what one is directly aware of or by representational content are instances of what Gilbert Harman has called “mental paint” (Block, 1990; Harman, 1990). The claim of this paper is that empirical facts about attention point in the direction of mental paint. The argument starts with the claim (later modified) that when one moves one's attention around a scene while keeping one's eyes fixed, the phenomenology of perception can change in ways that do not reflect which qualities of objects one is directly aware of or the way the world is represented to be. These changes in the phenomenology of perception cannot be accounted for in terms of awareness of or representation of the focus of attention because they manifest themselves in experience as differences in apparent contrast, apparent color saturation, apparent size, apparent speed, apparent time of occurrence and other appearances. There is a way of coping with these phenomena in terms of vague contents, but vague contents cannot save direct realism or representationism because the kind of vagueness required clashes wth the phenomenology itself. (shrink)
For nearly thirty years, there has been a consensus (at least in English-speaking countries) that reductionism is a mistake and that there are autonomous special sciences. This consensus has been based on an argument from multiple realizability. But Jaegwon Kim has argued persuasively that the multiple realizability argument is flawed.1 I will sketch the recent history of the debate, arguing that much --but not all--of the anti-reductionist consensus survives Kim's critique. This paper was originally titled "Anti-Reductionism Strikes Back", but in (...) the course of writing the paper, I came to think that the concepts used in the debate would not serve either position very well. (shrink)
This article concerns the interplay between two issues that involve both philosophy and neuroscience: whether the content of phenomenal consciousness is 'rich' or 'sparse', whether phenomenal consciousness goes beyond cognitive access, and how it would be possible for there to be evidence one way or the other.
How can we disentangle the neural basis of phenomenal consciousness from the neural machinery of the cognitive access that underlies reports of phenomenal consciousness? We can see the problem in stark form if we ask how we could tell whether representations inside a Fodorian module are phenomenally conscious. The methodology would seem straightforward: find the neural natural kinds that are the basis of phenomenal consciousness in clear cases when subjects are completely confident and we have no reason to doubt their (...) authority, and look to see whether those neural natural kinds exist within Fodorian modules. But a puzzle arises: do we include the machinery underlying reportability within the neural natural kinds of the clear cases? If the answer is ‘Yes’, then there can be no phenomenally conscious representations in Fodorian modules. But how can we know if the answer is ‘Yes’? The suggested methodology requires an answer to the question it was supposed to answer! The paper argues for an abstract solution to the problem and exhibits a source of empirical data that is relevant, data that show that in a certain sense phenomenal consciousness overflows cognitive accessibility. The paper argues that we can find a neural realizer of this overflow if assume that the neural basis of phenomenal consciousness does not include the neural basis of cognitive accessibility and that this assumption is justified (other things equal) by the explanations it allows. (shrink)
(Wittgenstein, 1968) endorsed one kind of inverted spectrum hypothesis and rejected another. This paper argues that the kind of inverted spectrum hypothesis that Wittgenstein endorsed (the "innocuous" inverted spectrum hypothesis) is the thin end of the wedge that precludes a Wittgensteinian critique of the kind of inverted spectrum hypothesis he rejected (the "dangerous" kind). The danger of the dangerous kind is that it provides an argument for qualia, where qualia are (for the purposes of this paper) contents of (...) experiential states which cannot be fully captured in natural language. I will pinpoint the difference between the innocuous and dangerous scenarios that matters for the argument for qualia, give arguments in favor of the coherence and possibility of the dangerous scenario, and try to show that some standard arguments against inverted spectra are ineffective against the version of the dangerous scenario I will be advocating. The leading idea of the paper is that an argument for qualia based on spectrum inversion does not require that the inversion be behaviorally indistinguishable. At one crucial point, I will rely on a less controversial version of an argument I gave in Block (1999). Wittgenstein's views provide a convenient starting point for a paper that is much more about qualia than about Wittgenstein. (shrink)
Representationism1, as I use the term, says that the phenomenal character of an experience just is its representational content, where that representational content can itself be understood and characterized without appeal to phenomenal character. Representationists seem to have a harder time handling pain than visual experience. (I say 'seem' because in my view, representationists cannot actually handle either type of experience successfully, but I will put that claim to one side here.) I will argue that Michael Tye's (2004) heroic attempt (...) at a representationist theory of pain, although ingenious and enlightening, does not adequately come to terms with the root of this difference. (shrink)
This is a charming and engaging book that combines careful attention to the phenomenology of experience with an appreciation of the psychology and neuroscience of perception. In some of its aimsfor example, to show problems with a rigid version of a view of visual perception as an inverse optics process of constructing a static 3-D representation from static 2-D information on the retina--it succeeds admirably. As No points out, vision is a process that depends on interactions between the perceiver and (...) the environment and involves contributions from sensory systems other than the eye. He is at pains to note that vision is not passive. His analogy with touch is to the point: touch involves skillful probing and movement, and so does vision, although less obviously and in my view less centrally so. This much is certainly widely accepted among vision scientistsalthough mainstream vision scientists (represented, for example, by Stephen Palmers excellent textbook<sup>2</sup>) view these points as best seen within a version of the inverse optics view that takes inputs as non-static and as including motor instructions (for example, involving eye movements and head movements).<sup>3</sup> The kind of point that No raises is viewed as important at the margins, but as not disturbing the main lines of the picture of vision that descendswith many changesfrom the pioneering work of David Marr in the 1980s (and before him, from Helmholtz). But No shows little interest in mainstream vision science, focusing on non-mainstream ideas in the science of perception, specifically ideas from the anti-representational psychologist J.J. Gibson, and also drawing on Wittgenstein and the phenomenology tradition. There is a sense throughout the book of revolution, of upsetting the applecart. This is a review from the point of view of the applecart. (shrink)
Qualia include the ways things look, sound and smell, the way it feels to have a pain; more generally, what it's like to have mental states. Qualia are experiential properties of sensations, feelings, perceptions and, in my view, thoughts and desires as well. But, so defined, who could deny that qualia exist? Yet, the existence of qualia is controversial. Here is what is controversial: whether qualia, so defined, can be characterized in intentional, functional or purely (...) cognitive terms. Opponents of qualia think that the content of experience is intentional content (like the content of thought), or that experiences are functionally definable, or that to have a qualitative state is to have a state that is monitored in a certain way or accompanied by a thought to the effect that I have that state. If we include the idea that experiential properties are not intentional or functional or purely cognitive in the definition of `qualia', then it is controversial whether there are qualia. (shrink)
In this note, I will discuss one issue concerning the main argument of Mind in a Physical World (Kim, 1998), the Causal Exclusion Argument. The issue is whether it is a consequence of the Causal Exclusion Argument that all macro level causation (that is, causation above the level of fundamental physics) is an illusion, with all of the apparent causal powers of mental and other macro properties draining into the bottom level of physics. I will argue that such a consequence (...) would give us reason to reject the Causal Exclusion Argument. But there is also a stronger challenge, the charge that, if there is no bottom level of physics, the Causal Exclusion Argument has the consequence that “causal powers would drain away into a bottomless pit and there wouldn’t be any causation anywhere.” (81--page numbers that are not attributed to other works are to Kim, 1998). (shrink)
The greatest chasm in the philosophy of mind--maybe even all of philosophy-- divides two perspectives on consciousness. The two perspectives differ on whether there is anything in the phenomenal character of conscious experience that goes beyond the intentional, the cognitive and the functional. A convenient terminological handle on the dispute is whether there are.
There are a number of different matters that come under the heading of ‘consciousness’. One of them is phenomenality, the feeling of say a sensation of red or a pain, that is what it is like to have such a sensation or other experience. Another is reflection on phenomenality. Imagine two infants, both of which have pain, but only one of which has a thought about that pain. Both would have phenomenal states, but only the latter would have a state (...) of reflexive consciousness. This entry will start with phenomenality, moving later to reflexivity and then to one other kind of consciousness. (shrink)
I’m now looking at a soccer ball and a Nintendo Game Cube, and thus am having a perceptual experience of a sphere and a cube. My friend, blind from birth, (who’s helping me with the cleaning) is touching these items, and is thus having a perceptual experience of the same things. Not only are we perceiving the same items, but in doing so we apply the terms ‘sphere’ and ‘cube’, respectively, to them. Are we, in doing so, applying the same, (...) or different, perceptual concepts? (shrink)
O'Regan and Noe declare that the qualitative character of experience is constituted by the nature of the sensorimotor contingencies at play when we perceive. Sensorimotor contingencies are a highly restricted set of input-output relations. The restriction excludes contingencies that don’t essentially involve perceptual systems. Of course if the ‘sensory’ in ‘sensorimotor’ were to be understood mentalistically, the thesis would not be of much interest, so I assume that these contingencies are to be understood non-mentalistically. Contrary to their view, experience is (...) a matter of what mediates between input and output, not input-output relations all by themselves. However, instead of mounting a head-on collision with their view, I think it will be more useful to consider a consequence of their view that admits of obvious counterexamples. The consequence consists of two claims: (1) any two systems that share that highly restricted set of input-output relations are therefor experientially the same and (2) conversely, any two systems that share experience must share these sensorimotor contingencies. Once stated, the view is so clearly wrong that my ascription of it to them might be challenged. At least it is a consequence of a major strand in their view. Perhaps this will be an opportunity for them to disassociate themselves from it. I will limit myself to (1). (shrink)
There are two concepts of consciousness that are easy to confuse with one another, access-consciousness and phenomenal consciousness. However, just as the concepts of water and H2O are different concepts of the same thing, so the two concepts of consciousness may come to the same thing in the brain. The focus of this paper is on the problems that arise when these two concepts of consciousness are conflated. I will argue that John Searles reasoning about the function of consciousness goes (...) wrong because he conflates the two senses. And Francis Crick and Christof Koch fall afoul of the ambiguity in arguing that visual area V1 is not part of the neural correlate of consciousness. Crick and Kochs work raises issues that suggest that these two concepts of consciousness may have different (though overlapping) neural correlates--despite Crick and Kochs implicit rejection of this idea. (shrink)
Dehaene and Naccache, Dennett and Jack and Shallice â€œsee convergence coming from many different quarters on a version of the neuronal global workspace modelâ€ (Dennett, p. 1).Â (Boldface references are to papers in this volume.)Â On the contrary, even within this volume, there are commitments to very different perspectives on consciousness.Â And these differing perspectives are based on tacit differences in philosophical starting places that should be made explicit.Â Â Indeed, it is not clear that different uses of â€œconsciousnessâ€ and (...) â€œawarenessâ€ in this volume can be taken to refer to the same phenomenon.Â More specifically, I think there are three different concepts of consciousness in play in this issue.Â The global workspace model makes much more sense on one of these than on the others. (shrink)
Everyone would agree that the American flag is red, white and blue. Everyone should also agree that it looks red, white and blue to people with normal color vision in appropriate circumstances. If a philosophical theory led to the conclusion that the red stripes cannot look red to both men and women, both blacks and whites, both young and old, we would be reluctant (to say the least) to accept that philosophical theory. But there is a widespread philosophical view about (...) the nature of conscious experience that, together with some empirical facts, suggests that color experience cannot be veridical for both men and women, both blacks and whites, both young and old. (shrink)
There is reason to believe that people of different gender, race or age differ in spectra that are shifted relative to one another. Shifted spectra are not as dramatic as inverted spectra, but they can be used to make some of the same philosophical points.
Money is a cultural construction, leukemia is not. In which category does phenomenal consciousness fit? The issue is clarified by a distinction between what cultural phenomena causally influence and what culture constitutes. Culture affects phenomenal consciousness but it is ridiculous to suppose that culture constitutes it, even in part.
If a philosophical theory led to the conclusion that the red stripes cannot look red to both men and women, both blacks and whites, both young and old, we would be reluctant (to say the least) to accept that philosophical theory. But there is a widespread philosophical view about the nature of conscious experience that, together with some empirical facts, suggests that color experience cannot be veridical for both men and women, both blacks and whites, both young and old.
The explanatory gap . Consciousness is a mystery. No one has ever given an account, even a highly speculative, hypothetical, and incomplete account of how a physical thing could have phenomenal states. (Nagel, 1974, Levine, 1983) Suppose that consciousness is identical to a property of the brain, say activity in the pyramidal cells of layer 5 of the cortex involving reverberatory circuits from cortical layer 6 to the thalamus and back to layers 4 and 6,as Crick and Koch have suggested (...) for visual consciousness. (See Crick (1994).) Still, that identity itself calls out for explanation! Proponents of an explanatory gap disagree about whether the gap is permanent. Some (e.g. Nagel, 1974) say that we are like the scientifically naive person who is told that matter = energy, but does not have the concepts required to make sense of the idea. If we can acquire these concepts, the gap is closable. Others say the gap is uncloseable because of our cognitive limitations. (McGinn, 1991) Still others say that the gap is a consequence of the fundamental nature of consciousness. (shrink)
According to Conceptual Role Semantics ("CRS"), the meaning of a representation is the role of that representation in the cognitive life of the agent, e.g. in perception, thought and decision-making. It is an extension of the well known "use" theory of meaning, according to which the meaning of a word is its use in communication and more generally, in social interaction. CRS supplements external use by including the role of a symbol inside a computer or a brain. The uses appealed (...) to are not just actual, but also counterfactual: not only what effects a thought does have, but what effects it would have had if stimuli or other states had differed. The view has arisen separately in philosophy (where it is sometimes called "inferential," or "functional" role semantics) and in cognitive science (where it is sometimes called "procedural semantics"). The source of the view is Wittgenstein (1953) and Sellars, but the source in contemporary philosophy is a series of papers by Harman (see his 1987) and Field (1977). Other proponents in philosophy have included Block, Horwich, Loar, McGinn and Peacocke (1992). In cognitive science, they include Woods (1981) and Miller and Johnson-Laird (1976). (See references in Block, 1987.). (shrink)
The first problem concerns the famous Swampman who comes into existence as a result of a cosmic accident in which particles from the swamp come together, forming a molecular duplicate of a typical human. Reasonable people can disagree on whether Swampman has intentional contents. Suppose that Swampman marries Swampwoman and they have children. Reasonable people will be inclined to agree that there is something it is like for Swampchild when "words" go through his mind or come out of his mouth. (...) Fred Dretske (1995) claims that if the materialist is to have any theory of intentional content at all, he has no option other than denying it. He is committed to the view that since phenomenal character is a kind of representational content that derives from evolution, the swampchildren have no phenomenal character. Zombiehood is hereditary. (So long as there is no evolution.) If your grandparents are all swamp-people, you are a zombie. (shrink)