The paper criticizes epistemological conceptions of analytic or conceptual truth, on which assent to such truths is a necessary condition of understanding them. The critique involves no Quinean scepticism about meaning. Rather, even granted that a paradigmatic candidate for analyticity is synonymy with a logical truth, both the former and the latter can be intelligibly doubted by linguistically competent deviant logicians, who, although mistaken, still constitute counterexamples to the claim that assent is necessary for understanding. There are no analytic or (...) conceptual truths in the epistemological sense. The critique is extended to purportedly analytic inference rules. An alternative account is sketched on which understanding a word is a matter of participation in a linguistic practice, while synonymy and concept identity consist in sameness of truth-conditional semantic properties. Although there are philosophical questions about concepts, the idea that philosophical questions in general are conceptual questions generates only an illusion of insight into philosophical methodology. (shrink)

The paper criticizes epistemological conceptions of analytic or conceptual truth, on which assent to such truths is a necessary condition of understanding them. The critique involves no Quinean scepticism about meaning. Rather, even granted that a paradigmatic candidate for analyticity is synonymy with a logical truth, both the former and the latter can be intelligibly doubted by linguistically competent deviant logicians, who, although mistaken, still constitute counterexamples to the claim that assent is necessary for understanding. There are no analytic or (...) conceptual truths in the epistemological sense. The critique is extended to purportedly analytic inference rules. An alternative account is sketched on which understanding a word is a matter of participation in a linguistic practice, while synonymy and concept identity consist in sameness of truth-conditional semantic properties. Although there are philosophical questions about concepts, the idea that philosophical questions in general are conceptual questions generates only an illusion of insight into philosophical methodology. (shrink)

A broad range of evidence regarding the functional organization of the vertebrate brain – spanning from comparative neurology to experimental psychology and neurophysiology to clinical data – is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form (...) a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain – culminating in the cerebral cortex of mammals – came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. (Published Online May 1 2007) Key Words: action selection; anencephaly; central decision making; consciousness; control architectures; hydranencephaly; macrosystems; motivation; target selection; zona incerta. (shrink)

The paper criticizes epistemological conceptions of analytic or conceptual truth, on which assent to such truths is a necessary condition of understanding them. The critique involves no Quinean scepticism about meaning. Rather, even granted that a paradigmatic candidate for analyticity is synonymy with a logical truth, both the former and the latter can be intelligibly doubted by linguistically competent deviant logicians, who, although mistaken, still constitute counterexamples to the claim that assent is necessary for understanding. There are no analytic or (...) conceptual truths in the epistemological sense. The critique is extended to purportedly analytic inference rules. An alternative account is sketched on which understanding a word is a matter of participation in a linguistic practice, while synonymy and concept identity consist in sameness of truth-conditional semantic properties. Although there are philosophical questions about concepts, the idea that philosophical questions in general are conceptual questions generates only an illusion of insight into philosophical methodology. (shrink)

Listening to subject’s commentaries can be a useful spur to novel scientific departures, as in studies of blindsight. Recently further testing has been possible with subject DB, who was a blindsight patient tested intensively over a period of 10 years and who was the subject of the book, . Essentially his original capacity is the same or somewhat more sensitive. Some further types of discriminations have now been tested that were not possible in the original study. But a new feature (...) was discovered, namely that he describes conscious after-images of a wide range of inducing stimuli of which he is unconscious. The properties of the after-images are briefly described, such as their occurrence following unseen colour patches, luminance changes, shape, spatial frequency, their long durations, showing inter-ocular transfer, as well as their conforming to Emmert’s Law. Various approaches are discussed towards finding the source of their generation, such as the use of after-images of colour mixes of separate inputs to the two eyes . They are also discussed in terms of after-images in normal subjects that are generated by imagination. The discovery offers a rare potential opportunity to compare the brain activity associated with both the conscious and unconscious attributes of the precisely the same stimuli in the same locus in the same subject. (shrink)

Ned Block argues that the higher-order (HO) approach to explaining consciousness is ‘defunct’ because a prominent objection (the ‘misrepresentation objection’) exposes the view as ‘incoherent’. What’s more, a response to this objection that I’ve offered elsewhere (Weisberg 2010) fails because it ‘amounts to abusing the notion of what-it’s-like-ness’ (xxx).1 In this response, I wish to plead guilty as charged. Indeed, I will continue herein to abuse Block’s notion of what-it’s-like-ness. After doing so, I will argue that the HO approach accounts (...) for the sense of what-it’s-like-ness that matters in a theory of consciousness. I will also argue that the only incoherence present in the HO theory is that generated by embracing Block’s controversial notion of what-it’s-like-ness, something no theorist of any stripe ought to do. Block is famous for (among other things) having introduced the notion of ‘phenomenal consciousness’ into contemporary philosophy of mind (Block 1995). This term is widely employed in the philosophical literature and it even appears in the empirical literature. But wide-speared usage has brought about divergent interpretations of the term. We can distinguish a ‘moderate’ and a ‘zealous’ reading of ‘phenomenal consciousness’. On the moderate reading, ‘phenomenal consciousness’ just means ‘experience’. Many people have embraced this sense of the term and use it to roughly pick out conscious experience involving sensory quality (states like conscious visual experiences or conscious pains, for example).2 On the zealous reading, however, phenomenal consciousness is held to be ‘distinct from any cognitive, intentional, or functional property’ (Block 1995: 234). That is, any explanation of phenomenal consciousness in exclusively cognitive, intentional, or functional terms will fail to capture, without remainder, what is really distinctive about phenomenal consciousness. Block, of course, is fully clear about embracing the zealous reading; indeed, his initial introduction of the notion is in those terms. The same ambiguity occurs with the much-used (and abused) idea of ‘what-it’s-like-ness’.. (shrink)

The experiments reported by Snodgrass, Shevrin, and Kopka appear to demonstrate that words are perceived even when overall forced-choice discrimination performance does not deviate from chance. We replicated their critical finding in two separate experiments; our results indicated that the subjects′ preferences for one of the two strategy conditions predicted significant deviations from chance performance in the pop condition, even though the overall performance in this condition did not differ from chance. In addition, we found that task preference had no (...) effect when blank cards rather than words were presented and that the words could not be detected when subjects were simply asked to decide on each trial whether a stimulus had been presented. These results suggest that it is possible to demonstrate perception below an objective threshold defined in terms of overall discrimination performance. As such, the results highlight the importance of considering individual differences in studies of perception without awareness. (shrink)

GY, an extensively studied human hemianope, is aware of salient visual events in his cortically blind field but does not call this ''vision.'' To learn whether he has low-level conscious visual sensations or whether instead he has gained conscious knowledge about, or access to, visual information that does not produce a conscious phenomenal sensation, we attempted to image process a stimulus s presented to the impaired field so that when the transformed stimulus T(s) was presented to the normal hemifield it (...) would cause a sensation similar to that caused by s in the impaired field. While degradation of contrast, spatio-temporal filtering, contrast reversal, and addition of smear and random blobs all failed to match the response to a flashed bar sf, moving textures of low contrast were accepted to match the response to a moving contrast-defined bar, sm. Orientation and motion direction discrimination of the perceptually matched stimuli [sm and T(sm)] was closely similar. We suggest that the existence of a satisfactory match indicates that GY has phenomenal vision. (shrink)

In two experiments subjects attempted to identify words presented below the objective threshold using two task strategies emphasizing either allowing a word to pop into their heads or looking carefully at the stimulus field . Words were selected to represent both meaningful and structural dimensions. We also asked subjects to indicate their strategy preference and to rate their motivation to perform well. In the absence of conscious perception, both strategy preference and word meaning interacted with strategy condition, mediating the accuracy (...) of subjects′ direct word identification judgments. Motivation also mediated performance. Word structure had no effect. Unconscious perception manifested only in the pop condition, underscoring the importance of task strategy in determining whether subliminal effects are observed. A follow-up control experiment using sham flashes demonstrated that strategy preference and motivation effects were not artifacts resulting from performance feedback cues. (shrink)

Van Selst and Merikle argued that the critical Preference × Strategy interaction findings could be alternatively explained by positing individual differences as a function of preference and strategy. They further argued that ruling out conscious perception depends on making the exhaustiveness assumption. We argue that the inhibitory effects satisfy objective threshold criteria regardless of possible individual differences in thresholds. We further suggest that the inhibitory findings are inherently incompatible with the conscious perception explanation and that therefore we do not need (...) to make the exhaustiveness assumption. We thus stand by our original conclusion that subliminal perception at the objective threshold has been demonstrated. (shrink)

No mental phenomenon is more central than consciousness to an adequate understanding of the mind. Nor does any mental phenomenon seem more stubbornly to resist theoretical treatment. Consciousness is so basic to the way we think about the mind that it can be tempting to suppose that no mental states exist that are not conscious states. Indeed, it may even seem mysterious what sort of thing a mental state might be if it is not a conscious state. On this way (...) of looking at things, if any mental states do lack consciousness, they are exceptional cases that call for special explanation or qualification. Perhaps dispositional or cognitive states exist that are not conscious, but nonetheless count as mental states. (shrink)

The distinction between perception and cognition has always had a firm footing in both cognitive science and folk psychology. However, there is little agreement as to how the distinction should be drawn. In fact, a number of theorists have recently argued that, given the ubiquity of top-down influences, we should jettison the distinction altogether. I reject this approach, and defend a pluralist account of the distinction. At the heart of my account is the claim that each legitimate way of marking (...) a border between perception and cognition deploys a notion I call ‘stimulus-control.’ Thus, rather than being a grab bag of unrelated kinds, the various categories of the perceptual are unified into a superordinate natural kind. (shrink)

Block () highlights two experimental studies of neglect patients which, he contends, provide ‘dramatic evidence’ for unconscious seeing. In Block's hands this is the highly non-trivial thesis that seeing of the same fundamental kind as ordinary conscious seeing can occur outside of phenomenal consciousness. Block's case for it provides an excellent opportunity to consider a large body of research on clinical syndromes widely held to evidence unconscious perception. I begin by considering in detail the two studies of neglect to which (...) Block appeals. I show why their interpretation as evidence of unconscious seeing faces a series of local difficulties. I then explain how, even bracketing these issues, a long-standing but overlooked problem concerning our criterion for consciousness problematizes the appeal to both studies. I explain why this problem is especially pressing for Block given his view that phenomenal consciousness overflows access consciousness. I further show that it is epidemic—not only affecting all report-based studies of unconscious seeing in neglect, but also analogous studies of the condition most often alleged to show unconscious seeing, namely blindsight. (shrink)

There are two very different ways of thinking about perception. According to representationalism, perceptual states are representations: they represent the world as being a certain way. They have content, which may or may not be different from the content of beliefs. They represent objects as having properties, sometimes veridically, sometimes not. According to relationalism, perception is a relation between the agent and the perceived object. Perceived objects are literally constituents of our perceptual states and not of the contents thereof. Perceptual (...) states are not representations. My aim is to argue that if we frame this debate as a debate about the individuation of perceptual states, rather than the nature of perception, then we can reconcile these two seemingly conflicting ways of thinking about perception. (shrink)

Do studies of perception without awareness and studies of perception without attention address a similar underlying concept of awareness? To answer this question, we compared qualitative differences in performance across variations in stimulus quality with qualitative differences in performance across variations in the direction of attention . The qualitative differences were based on three different phenomena: Stroop priming, false recognition, and exclusion failure. In all cases, variations in stimulus quality and variations in the direction of attention led to parallel findings. (...) These results suggest that perception with and without awareness and perception with and without attention are equivalent ways of describing the same underlying process distinction. (shrink)

As an alternative to establishing awareness thresholds, stimulus contexts in which there were either greater conscious or greater unconscious influences were defined on the basis of performance on an exclusion task. Target words were presented for brief durations and each target word was followed immediately by its three-letter stem. Subjects were instructed to complete each stem with any word other than the target word. With this task, failures to exclude target words indicate greater unconscious influences, whereas successful exclusion indicates greater (...) conscious influences. Conscious influences were dominant at long durations , but unconscious influences were dominant at short durations . Performance on the exclusion task successfully predicated both qualitative differences in Stroop priming and qualitative differences in recognition memory previously associated with the different effects of conscious and unconscious influences. Taken together, these results demonstrate that an exclusion task allows both unconscious and conscious influences to be defined in terms of significant deviations from baseline performance. As such, exclusion tasks provide a method for distinguishing conscious from unconscious influences that does not require establishing thresholds for null awareness. (shrink)

The disjunctive theory of perception claims that we should understand statements about how things appear to a perceiver to be equivalent to statements of a disjunction that either one is perceiving such and such or one is suffering an illusion (or hallucination); and that such statements are not to be viewed as introducing a report of a distinctive mental event or state common to these various disjoint situations. When Michael Hinton first introduced the idea, he suggested that the burden of (...) proof or disproof lay with his opponent, that what was needed was to show that our talk of how things look or appear to one.. (shrink)

Our aim in this paper is to raise a question about the relationship between theories of responsibility, on the one hand, and a commitment to conscious attitudes, on the other. Our question has rarely been raised previously. Among those who believe in the reality of human freedom, compatibilists have traditionally devoted their energies to providing an account that can avoid any commitment to the falsity of determinism while successfully accommodating a range of intuitive examples. Libertarians, in contrast, have aimed to (...) show that either physical indeterminacy or a certain kind of agent causation can find a place in the world for what they take to be genuine freedom. Few have considered whether moral responsibility requires a commitment to conscious attitudes.2 Our question derives from a confluence of two sources. First, there is reason to think that conscious attitudes matter to theories of responsibility, either directly, as a result of the latter’s commitments, or indirectly, by virtue of the assumptions that they make about certain intuitive examples. Second, there is accumulating evidence suggesting that there aren’t any conscious mental states possessing the sorts of causal roles required of propositional attitudes. Since theorists of responsibility should in general be concerned to make their views compatible with plausible claims about the natural world, the implications of this data should be carefully considered. Our aim is therefore to motivate and begin exploring answers to the following conditional question: If it should turn out that there are no conscious attitudes, then what would be the implications of this fact (if any) for theories of responsibility? We propose that theorists who aren’t skeptics about moral responsibility should examine their accounts, asking whether their theories (or the examples that motivate them) could survive the discovery that there are no conscious judgments, decisions, or evaluations. Since we take it that moral theorizing in general should operate with the weakest possible empirical assumptions about the natural world, such theorists should consider whether their accounts could be motivated in such a way as to be free of any commitment to the existence of conscious attitudes.. (shrink)

When the stored representation of the meaning of a stimulus is accessed through the processing of a sensory input it is maintained in an activated state for a certain amount of time that allows for further processing. This semantic activation is generally accompanied by conscious identification, which can be demonstrated by the ability of a person to perform discriminations on the basis of the meaning of the stimulus. The idea that a sensory input can give rise to semantic activation without (...) concomitant conscious identification was the central thesis of the controversial research in subliminal perception. Recently, new claims for the existence of such phenomena have arisen from studies in dichotic listening, parafoveal vision, and visual pattern masking. Because of the fundamental role played by these types of experiments in cognitive psychology, the new assertions have raised widespread interest. (shrink)

The rosy dawn of my title refers to that optimistic time when the logical concept of a natural kind originated in Victorian England. The scholastic twilight refers to the present state of affairs. I devote more space to dawn than twilight, because one basic problem was there from the start, and by now those origins have been forgotten. Philosophers have learned many things about classification from the tradition of natural kinds. But now it is in disarray and is unlikely to (...) be put back together again. My argument is less founded on objections to the numerous theories now in circulation, than on the sheer proliferation of incompatible views. There no longer exists what Bertrand Russell called ‘the doctrine of natural kinds’—one doctrine. Instead we have a slew of distinct analyses directed at unrelated projects. (shrink)

Two major functions of the visual system are discussed and contrasted. One function of vision is the creation of an internal model or percept of the external world. Most research in object perception has concentrated on this aspect of vision. Vision also guides the control of object-directed action. In the latter case, vision directs our actions with respect to the world by transforming visual inputs into appropriate motor outputs. We argue that separate, but interactive, visual systems have evolved for the (...) perception of objects on the one hand and the control of actions directed at those objects on the other. This 'duplex' approach to high-level vision suggests that Marrian or 'reconstructive' approaches and Gibsonian or 'purposive-animate-behaviorist' approaches need not be seen as mutually exclusive, but rather as complementary in their emphases on different aspects of visual function. (shrink)

A review of Lycan's Book "Consciousness".

We asked whether the influence of an invisible prime on movement is dependent on conscious movement expectations. Participants reached to a central target, which triggered a directional prime–mask arrow sequence. Participants were instructed that the visible arrows would most often signal a movement modification in a specific direction. Kinematic analyses revealed that responses to the visible mask were influenced by participants’ intentional bias, as movements were fastest when the more probable mask was displayed. In addition, responses were influenced by the (...) invisible prime without regard to its relationship to the more probable mask. Analysis of the time of initial trajectory modifications revealed that both primes influenced responses in a similar manner after accounting for participants’ bias. These results imply that invisible stimuli automatically activate their associated responses and that unconscious priming of the motor system is insensitive to the conscious expectations of the participant making the pointing movements. (shrink)

What is the role of conscious visual experience in the control and guidance of human behaviour? According to some recent treatments, the role is surprisingly indirect. Conscious visual experience, on these accounts, serves the formation of plans and the selection of action types and targets, while the control of 'online' visually guided action proceeds via a quasi-independent non-conscious route. In response to such claims, critics such as (Wallhagen [2007], pp. 539-61) have suggested that the notions of control and guidance invoked (...) are unacceptably vague, and that that the image of 'zombie systems' guiding action fails to take account of the possibility that there is genuine but unconceptualized, unnoticed, and/or unreportable experience taking place and guiding or controlling the actions. I address both sets of concerns. I try to show that refining and clarifying the key notions of control and guidance leaves the original argument intact, as does the appeal to unconceptualized, unnoticed, or unreportable experiences. The exercise serves, however, to highlight an important complex of considerations concerning the relations between control, agency, and experience. Better understanding these relations is, I suggest, an important source of insights concerning the nature of phenomenal experience. (shrink)