Probabilistic belief contraction has been a much neglected topic in the field of probabilistic reasoning. This is due to the difficulty in establishing a reasonable reversal of the effect of Bayesian conditionalization on a probabilistic distribution. We show that indifferent contraction, a solution proposed by Ramer to this problem through a judicious use of the principle of maximum entropy, is a probabilistic version of a full meet contraction. We then propose variations of indifferent contraction, using both the Shannon entropy measure (...) as well as the Hartley entropy measure, with an aim to avoid excessive loss of beliefs that full meet contraction entails. (shrink)
In this paper we investigate three approaches to iterated contraction, namely: the Moderate (or Priority) contraction, the Natural (or Conservative) contraction, and the Lexicographic contraction. We characterise these three contraction functions using certain, arguably plausible, properties of an iterated contraction function. While we provide the characterisation of the first two contraction operations using rationality postulates of the standard variety for iterated contraction, we found doing the same for the Lexicographic contraction more challenging. We provide its characterisation using a variation of (...) Epistemic ranking function instead. (shrink)
A t first glance you might not noorder, which afflicts about 0.5 percent of tice anything odd on meeting a American children. Neither researcher young boy with autism. But if had any knowledge of the other’s work, you try to talk to him, it will and yet by an uncanny coincidence each quickly become obvious that gave the syndrome the same name: autism, something is seriously wrong. He may not which derives from the Greek word autos, make eye contact with (...) you; instead he may meaning “self.” The name is apt, because avoid your gaze and fidget, rock his body the most conspicuous feature of the disorto and fro, or bang his head against the der is a withdrawal from social interacwall. More disconcerting, he may not be tion. More recently, doctors have adopted able to conduct anything remotely resemthe term “autism spectrum disorder” to bling a normal conversation. Even though make it clear that the illness has many rehe can experience emotions such as fear, lated variants that range widely in severity rage and pleasure, he may lack genuine but share some characteristic symptoms. empathy for other people and be oblivious Ever since autism was identified, reto subtle social cues that most children searchers have struggled to determine would pick up effortlessly. what causes it. Scientists know that sus- In the 1940s two physicians—Americeptibility to autism is inherited, although.. (shrink)
This article supplements our earlier paper on synaesthesia published in JCS (Ramachandran & Hubbard, 2001a). We discuss the phenomenology of synaesthesia in greater detail, raise several new questions that have emerged from recent studies, and suggest some tentative answers to these questions.
First Published on: 21 June 2007 To cite this Article: Ramachandran, Vilayanur S., McGeoch, Paul D., Williams, Lisa and Arcilla, Gerard (2007) 'Rapid Relief of Thalamic Pain Syndrome Induced by Vestibular Caloric Stimulation', Neurocase, 13:3, 185 - 188 To link to this article: DOI: 10.1080/13554790701450446 URL: http://dx.doi.org/10.1080/13554790701450446..
André Gallois’ (1993) modified account of restrictedly rigid designators (RRDs) does indeed block the objection I made to his original account (Gallois 1986; Ramachandran 1992). But, as I shall now show, there is a deeper problem with his approach which his modification does not shake off. The problem stems from the truth of the following compatibility claim: (CC) A term’s restrictedly rigidly designating (RR-designating) an object x is compatible with it designating an object y in a world W where (...) x exists but is distinct from y.1 It follows from (CC) that the necessary (contingent) truth of a sentence of the form “α is identical with β”, where “α” and “β” are RRDs of objects x and y respectively, does not require the necessary (contingent) identity of x and y. This is borne out by Gallois’ original example (see 1986, p. 58-63). Taking W to be the actual world, we have: (1) “Mary is identical with Mary” is necessarily true; yet “Mary” RR- designates Mary and Alice, which are only contingently identical. 1 I leave it to the reader to check that in Gallois’ own example (1986, p. 58), on the view he defends (pp. 62-63), and despite his modified characterisation of restricted rigidity, RDC# (1993, p. xx), “Mary” RR-designates Alice (as well as Mary) in W, but designates Mary and not A/ice in W1. Gallois has accepted this in correspondence. In light of (CC), while I agree with Gallois (1993, p. 153) that: (7) (a=b & ◊(a≠b)) → (∃x)(∃y)(x=y & ◊(x≠y)) is a theorem given RDC#, I dispute his defence of it (on p. 153). For, if (CC) is correct, the antecedent of (7) could be true even though a and b are identical in every world (where either exists)! (shrink)
A Russellian theory of (definite) descriptions takes an utterance of the form ‘The F is G’ to express a purely general proposition that affirms the existence of a (contextually) unique F: there is exactly one F [which is C] and it is G. Strawson, by contrast, takes the utterer to presuppose in some sense that there is exactly one salient F, but this is not part of what is asserted; rather, when the presupposition is not met, the utterance simply fails (...) to express a (true or false) proposition. A defender of Strawson’s approach, however, must square up to what appear to be straightforward counterexamples to the presupposition thesis, and must also provide an account of certain linguistic phenomena that supposedly demand treating descriptions as quantifiers, as the Russellian theory does. In this paper I propose fresh considerations in favour of Strawson’s approach. I shift attention from what the utterer presupposes to preconditions for the use of descriptions, and distinguish between referring and predicative uses of descriptions (not to be confused with referential and attributive uses); importantly, the referring and predicative uses have different preconditions, I argue, and these provide some satisfactory responses to the aforementioned challenges facing the Strawsonian. (shrink)
There are currently two main philosophical theories of perception - Direct Realism and the Representative Theory. The former is supported by most contemporary philosophers, whereas the latter forms the groundwork for most scientific theories in this area. The paper describes a recent experiment involving retinal and cortical rivalry that provides strong empirical evidence that the Direct Realist theory is incorrect. There are of course a large number of related experiments on visual perception that would tend to lead us to the (...) same conclusion, but the experiment described in this paper does so in a singularly direct and straightforward manner. Often the most telling experiments are the simplest. (shrink)
(1) The induced colours led to perceptual grouping and pop-out, (2) a grapheme rendered invisible through ‘crowding’ or lateral masking induced synaesthetic colours — a form of blindsight — and (3) peripherally presented graphemes did not induce colours even when they were clearly visible. Taken collectively, these and other experiments prove conclusively that synaesthesia is a genuine percep- tual phenomenon, not an effect based on memory associations from childhood or on vague metaphorical speech. We identify different subtypes of number–colour synaesthesia (...) and propose that they are caused by hyperconnectivity between col- our and number areas at different stages in processing; lower synaesthetes may have cross-wiring (or cross-activation) within the fusiform gyrus, whereas higher synaesthetes may have cross-activation in the angular gyrus. This hyperconnec- tivity might be caused by a genetic mutation that causes defective pruning of con- nections between brain maps. The mutation may further be expressed selectively (due to transcription factors) in the fusiform or angular gyri, and this may explain the existence of different forms of synaesthesia. If expressed very diffusely, there may be extensive cross-wiring between brain regions that represent abstract concepts, which would explain the link between creativity, metaphor and synaesthesia (and the higher incidence of synaesthesia among artists and poets). Also, hyperconnectivity between the sensory cortex and amygdala would explain the heightened aversion synaesthetes experience when seeing numbers printed in the ‘wrong’ colour. Lastly, kindling (induced hyperconnectivity in the temporal lobes of temporal lobe epilepsy [TLE] patients) may explain the purported higher incidence of synaesthesia in these patients. We conclude with a synaesthesia-based theory. (shrink)
Apotemnophilia, a disorder that blurs the distinction between neurology and psychiatry, is characterized by the intense and longstanding desire for amputation of a speci¢c limb. Here we present evidence from two individuals suggestive that this condition, long thought to be entirely psychological in origin, actually has a neurological basis. We found heightened skin conductance response..
Timothy Williamson (2000 ch. 5) presents a reductio against the luminosity of knowing, against, that is, the so-called KK-principle: if one knows p, then one knows (or is at least in a position to know) that one knows p.1 I do not endorse the principle, but I do not think Williamson’s argument succeeds in refuting it. My aim here is to show that the KK-principle is not the most obvious culprit behind the contradiction Williamson derives.
Jones and Coleman are among a handful of otherwise normal as a child and the number 5 was red and 6 was green. This the- people who have synesthesia. They experience the ordinary ory does not answer why only some people retain such vivid world in extraordinary ways and seem to inhabit a mysterious sensory memories, however. You might _think _of cold when you no-man’s-land between fantasy and reality. For them the sens- look at a picture of an ice cube, (...) but you probably do not feel es—touch, taste, hearing, vision and smell—get mixed up in- cold, no matter how many encounters you may have had with stead of remaining separate. ice and snow during your youth. Modern scientists have known about synesthesia since Another prevalent idea is that synesthetes are merely being 1880, when Francis Galton, a cousin of Charles Darwin, pub- metaphorical when they describe the note C flat as “red” or say lished a paper in _Nature _on the phenomenon. But most have that chicken tastes “pointy”—just as you and I might speak of brushed it aside as fakery, an artifact of drug use (LSD and a “loud” shirt or “sharp” cheddar cheese. Our ordinary lan- mescaline can produce similar effects) or a mere curiosity. guage is replete with such sense-related metaphors, and perhaps About four years ago, however, we and others began to un- synesthetes are just especially gifted in this regard. cover brain processes that could account for synesthesia. Along We began trying to find out whether synesthesia is a gen- the way, we also found new clues to some of the most mysteri- uine sensory experience in 1999. This deceptively simple ques- ous aspects of the human mind, such as the emergence of ab- tion had plagued researchers in this field for decades. One nat- stract thought, metaphor and perhaps even language. ural approach is to start by asking the subjects outright: “Is this A common explanation of synesthesia is that the affected just a memory, or do you actually see the color as if it were right people are simply experiencing childhood memories and asso- in front of you?” When we tried asking this question, we did ciations.. (shrink)
Timothy Williamson (2000) reckons that hardly any mental state is luminous, i.e. is such that if one were in it, then one would invariably be in a position to know that one was. To this end he presents an argument against the luminosity of feeling cold— which he claims generalizes to other phenomenal states, such as e.g. being in pain. As we shall see, however, no fewer than four lines of argument for that conclusion can be extracted from Williamson’s remarks. (...) This is not to suggest that it is unclear which of these strategies is the one Williamson intends to present; but it is instructive to consider the others for the light they shed on the issue and on his own reasoning. Three of these strategies, including Williamson’s intended, fail with little hope of revival—so I shall argue. The fourth, which has escaped attention in the literature, is perhaps more promising, but I think it too can be resisted, and I sketch a possible line of attack. My aim here is not to defend the luminosity of phenomenal states per se— indeed, I am undecided about the matter—but, rather, to uncover the different strategies which emerge from Williamson’s discussion, and show that they fall short of refuting luminosity. (shrink)
David Lewis’s counterpart-theoretic semantics for quantified modal logic is motivated originally by worries about identifying objects across possible worlds; the counterpart relation is grounded more cautiously on comparative similarity. The possibility of contingent identity is an unsought -- and in some eyes, unwelcome -- consequence of this approach. In this paper I motivate a Kripkean counterpart theory by way of defending the prior, pre-theoretical, coherence of contingent directness. Contingent identity follows for free. The theory is Kripkean in that the counterpart (...) relation is in a sense stipulated rather than grounded on similarity, and is such that no object has more than one counterpart at a world. This avoids a number of objections Fara and Williamson have recently levelled against counterpart theory generally; their other objections are addressed by enriching the theory with special quantifiers and actuality operators. (shrink)
On David Lewis's original analysis of causation, c causes e only if c is linked to e by a chain of distinct events such that each event in the chain (counter-factually) depends on the former one. But this requirement precludes the possibility of late pre-emptive causation, of causation by fragile events, and of indeterministic causation. Lewis proposes three different strategies for accommodating these three kinds of cases, but none of these turn out to be satisfactory. I offer a single analysis (...) of causation that resolves these problems in one go but which respects Lewis's initial insights. One distinctive feature of my account is that it accommodates indeterministic causation without resorting to probabilities. (shrink)
André Gallois (1998) attempts to defend the occasional identity thesis (OIT), the thesis that objects which are distinct at one time may nonetheless be identical at another time, in the face of two influential lines of argument against it. One argument involves Kripke’s (1971) notion of rigid designation and the other, Leibniz’s law (affirming the indiscernibility of identicals). It is reasonable for advocates of (OIT) to question the picture of rigid designation and the version of Leibniz’s law that these arguments (...) employ, but, the problem is, some form of rigidity is required for one to affirm the occasional identity of objects, and some (restricted) version of Leibniz’s law must be conceded if identity really is involved. Gallois accordingly recommends an account of rigidity and a version of Leibniz’s law to this end.1 We find Gallois’ proposals entirely inadequate to their task. We aim in this paper is to explicate and defend an alternative approach for occasional identity theorists. We do not seek to defend (OIT) per se; our aim, rather, is simply to show that the arguments from rigid designation and Leibniz’s law are inconclusive. Let’s begin with an outline of these arguments. (shrink)
We studied two otherwise normal, synaesthetic subjects who `saw' a speci¢c colour every time they saw a speci¢c number or letter. We conducted four experiments in order to show that this was a genuine perceptual experience rather than merely a memory association. (i)The synaesthetically induced colours could lead to perceptual grouping, even though the inducing numerals or letters did not. (ii)Synaesthetically induced colours were not experienced if the graphemes were presented peripherally. (iii)Roman numerals were ine¡ective: the actual number grapheme was (...) required. (iv)If two graphemes were alternated the induced colours were also seen in alternation. However, colours were no longer experienced if the graphemes were alternated at more than 4 Hz. We propose that grapheme colour synaesthesia arises from `cross-wiring' between the `colour centre' (area V4 or V8)and the `number area', both of which lie in the fusiform gyrus. We also suggest a similar explanation for the representation of metaphors in the brain: hence, the higher incidence of synaesthesia among artists and poets. (shrink)
Summary Transsexuals are individuals who identify as a member of the gender opposite to that which they are born. Many transsexuals report that they have always had a feeling of a mismatch between their inner gender-based ‘‘body image’’ and that of their body’s actual physical form. Often transsexuals undergo gender reassignment surgery to convert their bodies to the sex they feel they should have been born. The vivid sensation of still having a limb although it has been amputated, a phantom (...) limb, was first described by Weir Mitchell over a century ago. The same phenomenon is also occurs after amputation of the penis or a breast. Around 60% of men who have had to have their penis amputated for cancer will experience a phantom penis. It has recently been shown that a significant factor in these phantom sensations is ‘‘cross-activation’’ between the de-afferented cortex and surrounding areas. Despite this it also known that much of our body image is innately ‘‘hard-wired’’ into our brains; congenitally limbless patients can still experience phantom sensations. We hypothesise that, perhaps due to a dissociation during embryological development, the brains of transsexuals are ‘‘hard-wired’’ in manner, which is opposite to that of their biological sex. We go on to predict that male-to-female transsexuals will be much less likely to experience a phantom penis than a ‘‘normal’’ man who has had his penis amputated for another reason. The same will be true of female-to-male transsexuals who have had breast removal surgery. We also predict that some female-to-male transsexuals will have a phantom penis even although there is not one physically there. We believe that this is an easily testable hypothesis, which, if correct, would offer insights into both the basis of transsexuality and provide farther evidence that we have a gender specific body image, with a strong innate component that is ‘‘hard-wired’’ into our brains. This would furnish us with a better understanding the mechanism by which nature and nurture interact to link the brain-based internal body image with external sexual morphology.. (shrink)
Summary Apotemnophilia, or body integrity image disorder (BIID), is characterised by a feeling of mismatch between the internal feeling of how one’s body should be and the physical reality of how it actually is. Patients with this condition have an often overwhelming desire for an amputation- of a specific limb at a specific level. Such patients are not psychotic or delusional, however, they do express an inexplicable emotional abhorrence to the limb they wish removed. It is also known that such (...) patients show a left-sided preponderance for their desired amputation. Often they take drastic action to be rid of the offending limb. Given the left-sided bias, emotional rejection and specificity of desired amputation, we suggest that there are clear similarities to be drawn between BIID and somatoparaphrenia. In this rare condition, which follows a right parietal stroke, the patient rejects (usually) his left arm as ‘‘alien’’. We go on to hypothesis that a dysfunction of the right parietal lobe is also the cause of BIID. We suggest that this leads to an uncoupling of the construct of one’s body image in the right parietal lobe from how one’s body physically is. This hypothesis would be amenable to testing by response to cold-water vestibular caloric stimulation, which is known to temporarily treat somatoparaphrenia. It could also be investigated using functional brain imaging and skin conductance response. If correct our hypothesis not only suggests why BIID arises, but also, in caloric stimulation a therapeutic avenue for this chronic and essentially untreatable condition. (shrink)
How the brain constructs one's inner sense of gender iden-tity is poorly understood. On the other hand, the phenomenon of phantom sensations-- the feeling of still having a body-part after amputation--has been much studied. Around 60% of men experience a phantom penis post-penectomy. As transsexuals report a mismatch between their inner gender identity and that of their body, we won-dered what could be learnt from this regarding innate gender-specific body image. We surveyed male-to-female transsexuals regarding the incidence of phantoms post-gender (...) reassignment surgery. Addition-ally, we asked female-to-male transsexuals if they had ever had the sensation of having a penis when there was not one physically there. In post-operative male-to-female transsexuals the incidence of phan-tom penises was significantly reduced at 30%. Remarkably, over 60% of female-to-male transsexuals also reported phantom penises. We explain the absence/presence of phantoms here by postulating a mis-match between the brain's hardwired gender-specific body image and the external somatic gender. Further studies along these lines may provide penetrating insights into the question of how nature and nur-ture interact to produce our brain-based body image. (shrink)
Advocates of occasional identity have two ways of interpreting putative cases of fission and fusion. One way?we call it the Creative view?takes fission to involve an object really dividing (or being replicated), thereby creating objects which would not otherwise have existed. The more ontologically parsimonious way takes fission to involve merely the ?separation? of objects that were identical before: strictly speaking, no object actually divides or is replicated, no new objects are created. In this paper we recommend the Creative approach (...) as the best way of dealing with certain problem cases involving teletransportation. Our considerations yield novel takes on psychological-continuity theories of personal identity and survival, and on the puzzle of Theseus' ship. (shrink)
Here we outline a simple method of using two mirrors which allows one to stand outside oneself. This method demonstrates that registration of vision with touch and proprioception is crucial for the perception of the corporeal self. Our method may also allow the disassociation of taste from touch, proprioception, and movement.
André Gallois (1998) attempts to defend the occasional identity thesis (OIT), the thesis that objects which are distinct at one time may nonetheless be identical at another time, in the face of two influential lines of argument against it. One argument involves Kripke’s (1971) notion of rigid designation and the other, Leibniz’s law (affirming the indiscernibility of identicals). It is reasonable for advocates of (OIT) to question the picture of rigid designation and the version of Leibniz’s law that these arguments (...) employ, but, the problem is, some form of rigidity is required for one to affirm the occasional identity of objects, and some (restricted) version of Leibniz’s law must be conceded if identity really is involved. Gallois accordingly recommends an account of rigidity and a version of Leibniz’s law to this end.1 We find Gallois’ proposals entirely inadequate to their task. We aim in this paper is to explicate and defend an alternative approach for occasional identity theorists. We do not seek to defend (OIT) per se; our aim, rather, is simply to show that the arguments from rigid designation and Leibniz’s law are inconclusive. Let’s begin with an outline of these arguments. (shrink)
Synesthesia is a condition in which stimulation of one sensory modality causes unusual experiences in a second, unstimulated modality. Although long treated as a curiosity, recent research with a combination of phenomenological, behavioral, and neuroimaging methods has begun to identify the cognitive and neural basis of synesthesia. Here, we review this literature with an emphasis on grapheme-color synesthesia, in which viewing letters and numbers induces the perception of colors. We discuss both the substantial progress that has been made in the (...) past fifteen years and some open questions. In particular, we focus on debates in the field relating to the neural basis of synesthesia, including the relationship between synesthesia and attention and the role of meaning in synesthetic colors. We propose that some, but probably not all, of these differences can be accounted for by differences in the synesthetes studied and discuss some methodological implications of these individual differences. (shrink)
It is well known that Russell's theory of descriptions has difficulties with descriptions occurring within desire reports. I consider a flawed argument from such a case to the conclusion that descriptions have a referring use, some responses to this argument on behalf of the Russellian, and finally rejoinders to these responses which press the point home.
David Lewis modified his original theory of causation in response to the problem of ‘late preemption’ (see 1973b; 1986b: 193-212). However, as we will see, there is a crucial difference between genuine and preempted causes that Lewis must appeal to if his solution is to work. We argue that once this difference is recognized, an altogether better solution to the preemption problem presents itself.
In Knowledge and Its Limits Timothy Williamson argues against the luminosity of phenomenal states in general by way of arguing against the luminosity of feeling cold, that is, against the view that if one feels cold, one is at least in a position to know that one does. In this paper I consider four strategies that emerge from his discussion, and argue that none succeeds.
Subjects perceived touch sensations as arising from a table (or a rubber hand) when both the table (or the rubber hand) and their own real hand were repeatedly tapped and stroked in synchrony with the real hand hidden from view. If the table or rubber hand was then ‘injured’, subjects displayed a strong skin conductance response (SCR) even though nothing was done to the real hand. Sensations could even be projected to anatomically impossible locations. The illusion was much less vivid, (...) as indicated by subjective reports and SCR, if the real hand was simultaneously visible during stroking, or if the real hand was hidden but touched asynchronously. The fact that the illusion could be significantly diminished when the real hand was simultaneously visible suggests that the illusion and associated SCRs were due to perceptual assimilation of the table (or rubber hand) into one’s body image rather than associative conditioning. These experiments demonstrate the malleability of body image and the brain’s remarkable capacity for detecting statistical correlations in the sensory input. (shrink)
Anydomainofscientificresearchhasitssustainingorthodoxy. Thatis, research on a problem, whether in astronomy, physics, or biology, is con- ducted against a backdrop of broadly shared assumptions. It is these as- sumptionsthatguideinquiryandprovidethecanonofwhatisreasonable-- of what "makes sense." And it is these shared assumptions that constitute a framework for the interpretation of research results. Research on the problem of how we see is likewise sustained by broadly shared assump- tions, where the current orthodoxy embraces the very general idea that the business of the visual system is to (...) create a detailed replica of the visual world, and that it accomplishes its business via hierarchical organization and by operatingessentiallyindependently of other sensorymodalitiesas well as independently of previous learning, goals, motor planning, and motor execution. (shrink)
Kripke (1977) presents an argument designed to show that the considerations in Donnellan (1966) concerning attributive and referential uses of (definite) descriptions do not, by themselves, refute Russell’s (1905) unitary theory of description sentences (RTD), which takes (utterances of) them to express purely general, quantificational, propositions. Against Kripke, Marga Reimer (1998) argues that the two uses do indeed reflect a semantic ambiguity (an ambiguity at the level of literal truth conditions). She maintains a Russellian (quantificational) analysis of utterances involving attributively (...) used descriptions but attempts to defend the following two claims about utterances involving referentially used descriptions (referential utterances) (1998, p. 89). (shrink)
This paper considers, and rejects, three strategies aimed at showing that the KK-principle fails even in most favourable circumstances (all emerging from Williamson’s Knowledge and its Limits ). The case against the final strategy provides positive grounds for thinking that the principle should hold good in such situations.
The mechanism by which humans perceive others differs greatly from how humans perceive inanimate objects. Unlike inanimate objects, humans have the distinct property of being “like me” in the eyes of the observer. This allows us to use the same systems that process knowledge about self-performed actions, self-conceived thoughts, and self-experienced emotions to understand actions, thoughts, and emotions in others. The authors propose that internal simulation mechanisms, such as the mirror neuron system, are necessary for normal development of recognition, imitation, (...) theory of mind, empathy, and language. Additionally, the authors suggest that dysfunctional simulation mechanisms may underlie the social and communicative deficits seen in individuals with autism spectrum disorders. (shrink)
In this note I revive a lingering (albeit dormant) account of rigid designation from the pages of Mind with the aim of laying it to rest. Why let a sleeping dog lie when you can put it down? André Gallois (1986) has proposed an account of rigid designators that allegedly squares with Saul Kripke’s (1980) characterisation of them as terms which designate the same object in all possible worlds, but on which, contra Kripke, identity sentences involving rigid designators may be (...) merely contingently true. This suits Gallois, as he finds the notion of contingent identity coherent. Thus, the thrust of Gallois’ thesis is that his account of rigidity is preferable to Kripke’s because his accommodates a coherent metaphysical viewpoint, whereas Kripke’s doesn’t. Gallois has thwarted one unconvincing challenge (see Carter 1987; Gallois 1988) and his account, as yet, remains untainted. But not for long, I hope.1 Let us assume, for the sake of argument, that the notion of contingent identity is coherent, that, in other words, it makes—or can make—sense to say that certain (possible) objects are identical in one world but distinct in another. What I shall argue here is that Gallois’ account of rigidity would prevent us from expressing the contingent nonidentity of objects; if so, this is a significant failing of the account, for, as it will emerge, clearly Gallois is committed to the contingency of non-identity. (shrink)
An utterance of a sentence involving an incomplete (definite) description, ‘the F’, where the context—even taking the speaker’s intentions into account—does not determine a unique F, would be unintelligible. But an utterance (in the same context) of the corresponding Russellian paraphrase would not be unintelligible. So I urged in ‘A Strawsonian objection to Russell’s theory of descriptions’ (ANALYSIS 53, 1993, pp. 209-12). I compared an utterance of (1) The table is covered with books. with an utterance of (1)’s Russellian paraphrase..
Summary Ideomotor apraxia is a cognitive disorder in which the patient loses the ability to accurately perform learned, skilled actions. This is despite normal limb power and coordination. It has long been known that left supramarginal gyrus lesions cause bilateral upper limb apraxia and it was proposed that this area stored a visualkinaesthetic image of the skilled action, which was translated elsewhere in the brain into the pre-requisite movement formula. We hypothesise that, rather than these two functions occurring separately, both (...) are complementary functions of chains of ‘‘mirror neurons’’ within the left inferior parietal lobe. We go on to propose that this neural mechanism in the supramarginal gyrus and its projection zones, which originally evolved to allow the creation of a direct map between vision and movement, was subsequently exapted to allow other sorts of cross-domain mapping and in particular those sorts of abstract re-conceptualisation, such as metaphor, that make mankind unique. (shrink)
Several recent lines of inquiry have pointed to the amygdala as a potential lesion site in autism. Because one function of the amygdala may be to produce autonomic arousal at the sight of a signi¢cant face, we compared the responses of autistic children to their mothers’ face and to a plain paper cup. Unlike normals, the autistic children as a whole did not show a larger response to the person than to the cup. We also monitored sympathetic activity in autistic (...) children as they engaged in a wide range of everyday behaviours. The children tended to use self-stimulation activities in order to calm hyper-responsive activity of the sympathetic (`¢ght or £ight’) branch of the autonomic nervous system. A small percentage of our autistic subjects had hyporesponsive sympathetic activity, with essentially no electrodermal responses except to self-injurious behaviour. We sketch a hypothesis about autism according to which autistic children use overt behaviour in order to control a malfunctioning autonomic nervous system and suggest that they have learned to avoid using certain processing areas in the temporal lobes. (shrink)
In this commentary we discuss a predictive sensorimotor illusion, the size-weight illusion, in which the smaller of two objects of equal weight is perceived as heavier. We suggest that Grush's emulation theory can explain this illusion as a mismatch between predicted and actual sensorimotor feedback, and present preliminary data suggesting that the cerebellum may be critical for implementing the emulator.
identity sentences let us call them, can be informative. [2] But if, as intuition suggests, identity is a (binary) relation between objects, which holds between precisely every object and itself, then sentences of the form ‘a=a’ and ‘a=b’, if true, would seem to affirm precisely the same thing of precisely the same object. The question arises: how, then, can someone can find one identity sentence more informative than another?
��Grapheme-color synaesthesia is a neurological phenomenon in which particular graphemes, such as the numeral 9, automatically induce the simultaneous perception of a particular color, such as the color red. To test whether the concurrent color sensations in graphemecolor synaesthesia are treated as meaningful stimuli, we recorded event-related brain potentials as 8 synaesthetes and 8 matched control subjects read sentences such as ‘‘Looking very clear, the lake was the most beautiful hue of 7.’’ In synaesthetes, but not control subjects, congruous graphemes, (...) compared with incongruous graphemes, elicited a more negative N1 component, a less positive P2 component, and a less negative N400 component. Thus, contextual congruity of synaesthetically induced colors altered the brain response to achromatic graphemes beginning 100 ms postonset, affecting pattern-recognition, perceptual, and meaning-integration processes. The results suggest that grapheme-color synaesthesia is automatic and perceptual in nature and also suggest that the connections between colors and numbers are bidirectional. (shrink)
Aims. Saul Kripke’s (1977) argument defending Russell’s theory of (definite) descriptions (RTD) against the possible objection that Donnellan’s (1966) distinction between attributive and referential uses of descriptions marks a semantic ambiguity has been highly influential.1 Yet, as I hope you’ll be persuaded, Kripke’s line of reasoning— in particular, the ‘thought-experiment’ it involves—has not been duly explored. In section II, I argue that while Kripke’s argument does ward off a fairly ill-motivated ambiguity theory, it is far from clear whether it would (...) succeed against more realistic candidates. If the central point I make in this regard is correct, it tells not only against Kripke’s argument but also against what has become a fairly orthodox line against the ambiguity thesis (as I shall call it). In section III, I compare Kripke’s defence of Russell with his ‘schmidentity’ argument (1980, p. 108), which involves essentially the same kind of thought-experiment. But, as I shall show, the latter argument contains an added twist which converts what otherwise would be merely a defence of one semantic theory into an attack against its rival. In section IV, I argue that the offensive strategy is unsound and attempt to locate its error. I conclude by drawing a (not unfamiliar) moral concerning the semantics—pragmatics distinction. (shrink)
The nanomedicine field is fast evolving toward complex, “active,” and interactive formulations. Like many emerging technologies, nanomedicine raises questions of how human subjects research (HSR) should be conducted and the adequacy of current oversight, as well as how to integrate concerns over occupational, bystander, and environmental exposures. The history of oversight for HSR investigating emerging technologies is a patchwork quilt without systematic justification of when ordinary oversight for HSR is enough versus when added oversight is warranted. Nanomedicine HSR provides an (...) occasion to think systematically about appropriate oversight, especially early in the evolution of a technology, when hazard and risk information may remain incomplete. This paper presents the consensus recommendations of a multidisciplinary, NIH-funded project group, to ensure a science-based and ethically informed approach to HSR issues in nanomedicine, and to integrate HSR analysis with analysis of occupational, bystander, and environmental concerns. We recommend creating two bodies, an interagency Human Subjects Research in Nanomedicine (HSR/N) Working Group and a Secretary's Advisory Committee on Nanomedicine (SAC/N). HSR/N and SAC/N should perform 3 primary functions: (1) analysis of the attributes and subsets of nanomedicine interventions that raise HSR challenges and current gaps in oversight; (2) providing advice to relevant agencies and institutional bodies on the HSR issues, as well as federal and federal-institutional coordination; and (3) gathering and analyzing information on HSR issues as they emerge in nanomedicine. HSR/N and SAC/N will create a home for HSR analysis and coordination in DHHS (the key agency for relevant HSR oversight), optimize federal and institutional approaches, and allow HSR review to evolve with greater knowledge about nanomedicine interventions and greater clarity about attributes of concern. (shrink)
An âinvertedâ reasoner is someone who finds the inferences we find easy, inversely difficult, and those that we find difficult, inversely easy. The notion was initially introduced by Christopher Cherniak in his book, Minimal Rationality, and appealed to by Stephen Stich in The Fragmentation of Reason. While a number of difficulties have been noted about what reasoning would amount to for such a reasoner, what has not been brought out in the literature is that such a reasoner is in fact (...) logically impossible. This is what I hope to demonstrate in this paper. (shrink)
This article reviews the potential use of visual feedback, focusing on mirror visual feedback, introduced over 15 years ago, for the treatment of many chronic neurological disorders that have long been regarded as intractable such as phantom pain, hemiparesis from stroke and complex regional pain syndrome. Apart from its clinical importance, mirror visual feedback paves the way for a paradigm shift in the way we approach neurological disorders. Instead of resulting entirely from irreversible damage to specialized brain modules, some of (...) them may arise from short-term functional shifts that are potentially reversible. If so, relatively simple therapies can be devised—of which mirror visual feedback is an example—to restore function. (shrink)
In a recent article, Paul Noordhof (1999) has put forward an intriguing account of causation intended to work under the assumption of indeterminism. I am going to present four problems for the account, three which challenge the necessity of the conditions he specifies, and one which challenges their joint-sufficiency.
This paper defends a simple, externalist account of knowledge, incorporating familiar conditions mentioned in the literature, and responds to Timothy Williamson’s charge that any such analysis is futile because knowledge is semantically un-analyzable. The response, in short, is that even though such an account may not offer a reductive analysis of knowledge-by way of more basic, non-circular concepts-it still has an explanatory advantage over Williamson’s own position: it explains how belief can fail to be knowledge.
Timothy Williamson (2000) reckons that hardly any mental state is luminous, i.e. is such that if one were in it, then one would invariably be in a position to know that one was. This paper examines an argument he presents against the luminosity of feeling cold, which he claims generalizes to other phenomenal states, such as e.g. being in pain. As we shall see, the argument fails. However, our deliberations do yield two anti-luminosity results: a simple refutation of the claim (...) that one invariably knows whether one feels cold or not,1 and a counterexample to the luminosity of knowing—in effect, a counterexample to the (KK)- principle. (shrink)
The article focuses on issues relating to occupational exposures of researchers and lab workers, and exposures of bystanders such as health care workers and family members during HSR using nanomaterials. Such third-party exposures give rise to unique challenges relating to oversight as well as exposures to worker groups not previously studied. Given the current state of knowledge regarding health risks from such exposures, a more precautionary approach to oversight seems advisable.
This paper considers six comparatively neglected problems for David Lewis’s (1973; 1979) account of counterfactual conditionals (counterfactuals). Four, we shall see, can be tackled without major compromises. The remaining two objections, however, do demand a re-appraisal of Lewis’s project. One casts doubt on the account’s explanatory virtues and drives a wedge between what a counterfactual statement..
Murali Ramachandran has kindly provided me with four (alleged) counterexamples to the theory of causation which I recently put forward in Mind (Ramachandran 2000; Noordhof 1999). Space is limited for a response. Since this note will be published Ramachandran's paper, I will not set out the cases he gives. I refer the reader to the appropriate descriptions. I will also presume knowledge of the framework of my paper and just give page references in case this is helpful. (...) I will try to couch the discussion with as little reference to the technical apparatus of my paper as possible. Maybe the ideas will stand out more clearly that way. (shrink)
It is a common assumption in contemporary cognitive neuroscience that discovering a putative realized kind to be dissociably realized (i.e., to be realized in each instance by two or more distinct realizers) mandates splitting that kind. Here I explore some limits on this inference using two deceptively similar examples: the dissociation of declarative and procedural memory and Ramachandran's argument that the self is an illusion.
