Tim Bayne draws on philosophy, psychology, and neuroscience in defence of the claim that consciousness is unified. He develops an account of what it means to say that consciousness is unified, and then applies this account to a variety of cases - drawn from both normal and pathological forms of experience - in which the unity of consciousness is said to break down. He goes on to explore the implications of the unity of consciousness for theories of consciousness, for the (...) sense of embodiment, and for accounts of the self. The Unity of Consciousness draws on a wide range of findings within philosophy and the sciences of the mind to construct an account of the unity of consciousness that is both conceptually sophisticated and scientifically informed. (shrink)

Seeing, Doing, and Knowing is an original and comprehensive philosophical treatment of sense perception as it is currently investigated by cognitive neuroscientists. Its central theme is the task-oriented specialization of sensory systems across the biological domain. Sensory systems are automatic sorting machines; they engage in a process of classification. Human vision sorts and orders external objects in terms of a specialized, proprietary scheme of categories - colours, shapes, speeds and directions of movement, etc. This 'Sensory Classification Thesis' implies that sensation (...) is not a naturally caused image from which an organism must infer the state of the world beyond; it is more like an internal communication, a signal concerning the state of the world issued by a sensory system, in accordance with internal conventions, for the use of an organism's other systems. This is why sensory states are both easily understood and persuasive.Sensory classification schemes are purpose-built to serve the knowledge-gathering and pragmatic needs of particular types of organisms. They are specialized: a bee or a bird does not see exactly what a human does. The Sensory Classification Thesis helps clarify this specialization in perceptual content and supports a new form of realism about the deliverances of sensation: 'Pluralistic Realism' is based on the idea that sensory systems coevolve with an organism's other systems; they are not simply moulded to the external world. The last part of the book deals with reference in vision. Cognitive scientists now believe that vision guides the limbs by means of a subsystem that links up with the objects of physical manipulation in ways that bypass sensory categories. In a novel extension of this theory, Matthen argues that 'motion-guiding vision' is integrated with sensory classification in conscious vision. This accounts for the quasi-demonstrative form of visual states: 'This particular object is red', and so on. He uses this idea to cast new light on the nature of perceptual objects, pictorial representation, and the visual representation of space. (shrink)

In Consciousness and Persons: Unity and Identity, Michael Tye takes on the thorny issue of the unity of consciousness and answers these important questions: What exactly is the unity of consciousness? Can a single person have a divided consciousness? What is a single person? Tye argues that unity is a fundamental part of human consciousness -- something so basic to everyday experience that it is easy to overlook. For example, when we hear the sound of waves crashing on a beach (...) and at the same time see a red warning flag, there is an overall unity to our experience; the sound and the red shape are presented together in our consciousness. Similarly, when we undergo a succession of thoughts as we think something through, there is an experience of succession that unifies the thoughts into a conscious whole. But, Tye shows, consciousness is not always unified. Split-brain subjects, whose corpus callosum has been severed, are usually taken to have a divided or disunified consciousness. Their behavior in certain situations implies that they have lost the unity normal human subjects take for granted; it is sometimes even supposed that a split-brain subject is really two persons.Tye begins his account by proposing an account of the unity of experience at a single time; this account is extended over the succeeding chapters to cover bodily sensations at a single time and perceptual experience, bodily sensations, conscious thoughts, and felt moods at a single time. Tye follows these chapters with a discussion of the unity of experience through time. Turning to the split-brain phenomenon, he proposes an account of the mental life of split-brain subjects and argues that certain facts about these subjects offer support for his theory of unity. Finally, addressing the topic of the nature of persons and personal identity, Tye finds the two great historical accounts -- the ego theory and the bundle theory -- lacking and he makes an alternative proposal. He includes an appendix on the general representational approach to consciousness and its many varieties, because of the relevance of representationalism to the theory of unity being adanced. (shrink)

This book presents a comprehensive theory of consciousness. The initial chapter distinguishes six main forms of consciousness and sketches an account of each one. Later chapters focus on phenomenal consciousness, consciousness of, and introspective consciousness. In discussing phenomenal consciousness, Hill develops the representational theory of mind in new directions, arguing that all awareness involves representations, even awareness of qualitative states like pain. He then uses this view to undercut dualistic accounts of qualitative states. Other topics include visual awareness, visual appearances, (...) emotional qualia, and meta-cognitive processing. This important work will interest a wide readership of students and scholars in philosophy of mind and cognitive science. (shrink)

Much of the philosophical work on perception has focused on vision. Recently, however, philosophers have begun to correct this ‘tunnel vision’ by considering other modalities. Nevertheless, relatively little has been written about the chemical senses—olfaction and gustation. The focus of this paper is olfaction. In this paper, I consider the question: does human olfactory experience represents objects as thus and so? If we take visual experience as the paradigm of how experience can achieve object representation, we might think that the (...) answer to this question is no. I argue that olfactory experience does indeed represent objects—just not in a way that is easily read from the dominant visual case. (shrink)

Philosophers and cognitive scientists of perception by custom have investigated individual sense modalities in relative isolation from each other. However, perceiving is, in a number of respects, multimodal. The traditional sense modalities should not be treated as explanatorily independent. Attention to the multimodal aspects of perception challenges common assumptions about the content and phenomenology of perception, and about the individuation and psychological nature of sense modalities. Multimodal perception thus presents a valuable opportunity for a case study in mature interdisciplinary cognitive (...) science. This chapter aims to raise these issues against the background of unimodal approaches in the study of perception. It presents some of the central empirical findings concerning multimodality, and it explains the philosophical implications of these findings. Foremost, it aims to encourage and open avenues for future research. (shrink)

Many organisms possess multiple sensory systems, such as vision, hearing, touch, smell, and taste. The possession of multiple ways of sensing the world offers many benefits. However, combining information from different senses also poses many challenges for the nervous system. In recent years there has been dramatic progress in understanding how information from the different senses gets integrated in order to construct useful representations of external space. This volume brings together the leading researchers from a broad range of scientific approaches (...) to present the first overview of this central topic in cognitive neuroscience. (shrink)

Representational theories of mind cannot individuate the sense modalities in a principled manner. According to representationalism, the phenomenal character of experiences is determined by their contents. The usual objection is that inverted qualia are possible, so the phenomenal character of experiences may vary independently of their contents. But the objection is inconclusive. It raises difficult questions about the metaphysics of secondary qualities and it is difficult to see whether or not inverted qualia are possible. This paper proposes an alternative test (...) of representationalism. Do experiences in different sense modalities have the same phenomenal character when they share content? Psychological work on the perception of shape through vision and spatial hearing is discussed. This work shows that visual and auditory experiences differ in phenomenal character even in so far as they represent similar properties. This objection to representationalism does not invite questions about secondary qualities or depend on establishing metaphysical possibilities. (shrink)

Is consciousness multisensory? Obviously it is multisensory in certain ways. Human beings typically possess the capacity to have experiences in at least the five familiar sensory modalities, and quite possibly in a number of other less commonly recognised modalities as well. But there are other respects in which it is far from obvious that consciousness is multisensory. This chapter is concerned with one such respect. Οur concern here is with whether consciousness contains experiences associated with distinct modalities at the same (...) time. We will describe those who endorse a positive answer to this question as endorsing a multisensory view (MSV) of the structure of consciousness, and those who endorse a negative answer to this question as having a unisensory view (USV) of the structure of consciousness. (shrink)

Haptic touch is an inherently active and exploratory form of perception, involving both coordinated movements and an array of distinct sensory receptors in the skin. For this reason, some have claimed that haptic touch is not a single sense, but rather a multisensory collection of distinct sensory systems. Though this claim is often made, it relies on what I regard as a confused conception of multisensory interaction. In its place, I develop a nuanced hierarchy of multisensory involvement. According to this (...) hierarchy, touch turns out to be a single modality in that its various receptors assign their features to the same tangible objects. When we grasp an object a range of distinct properties?shape, warmth, heft, texture, etc.?are all felt to belong to the object, just as different visual properties are associated with a visual object. Paradigm multisensory experiences, on the other hand, involve associations between distinct perceptual experiences, as when the way something looks affects the way something sounds. Thus despite its functional and physiological diversity, haptic touch can be regarded as a single sense. (shrink)

This paper presents forms of multimodal perceptual experience that undermine the claim that each aspect of perceptual experience is modality specific. In particular, it argues against the thesis that all phenomenal character is modality specific (even making an allowance for co-conscious unity). It concludes that a multimodal perceptual episode may have phenomenal features beyond those that are associated with the specific modalities.

In the case of ventriloquism, seeing the movement of the ventriloquist dummy’s mouth changes your experience of the auditory location of the vocals. Some have argued that cases like ventriloquism provide evidence for the view that at least some of the content of perception is fundamentally multimodal. In the ventriloquism case, this would mean your experience has constitutively audio-visual content (not just a conjunction of an audio content and visual content). In this paper, I argue that cases like ventriloquism do (...) not in fact warrant that conclusion. I then try to make sense of crossmodal cases without appealing to fundamentally multimodal content. (shrink)

Object files (OFs) are hypothesized mid-level representations which mediate our conscious perception of persisting objects—e.g. telling us ‘which went where’. Despite the appeal of the OF framework, not previous research has directly explored whether OFs do indeed correspond to conscious percepts. Here we present at least one case wherein conscious percepts of ‘which went where’ in dynamic ambiguous displays diverge from the analogous correspondence computed by the OF system. Observers viewed a ‘bouncing/streaming’ display in which two identical objects moved such (...) that they could have either bounced off or streamed past each other. We measured two dependent variables: (1) an explicit report of perceived bouncing or streaming; and (2) an implicit ‘object-specific preview benefit’ (OSPB), wherein a ‘preview’ of information on a specific object speeds the recognition of that information at a later point when it appears again on the same object (compared to when it reappears on a different object), beyond display-wide priming. When the displays were manipulated such that observers had a strong bias to perceive streaming (on over 95% of the trials), there was nevertheless a strong OSPB in the opposite direction—such that the object files appeared to have ‘bounced’ even though the percept ‘streamed’. Given that OSPBs have been taken as a hallmark of the operation of object files, the five experiments reported here suggest that in at least some specialized (and perhaps ecologically invalid) cases, conscious percepts of ‘which went where’ in dynamic ambiguous displays can diverge from the mapping computed by the object-file system. (shrink)

In this paper we offer a theory of cross-modal objects. To begin, we discuss two kinds of linkages between vision and audition. The first is a duality. The the visual system detects and identifies surfaces ; the auditory system detects and identifies sources . Surfaces are illuminated by sources of light; sound is reflected off surfaces. However, the visual system discounts sources and the auditory system discounts surfaces. These and similar considerations lead to the Theory of Indispensable Attributes that states (...) the conditions for the formation of gestalts in the two modalities. The second linkage involves the formation of audiovisual objects, integrated cross-modal experiences. We describe research that reveals the role of cross-modal causality in the formation of such objects. These experiments use the canonical example of a causal link between vision and audition: a visible impact that causes a percussive sound. (shrink)

In _On The Soul_ (425a-b), Aristotle drew a distinction between those qualities that are perceptible only via a single sense and those that are perceptible by more than one. The latter qualities he called.

Processing the various features from different feature maps and modalities in coherent ways requires a dedicated integration mechanism . Many authors have related feature binding to conscious awareness but little is known about how tight this relationship really is. We presented subjects with asynchronous audiovisual stimuli and tested whether the two features were integrated. The results show that binding took place up to 350 ms feature-onset asynchronies, suggesting that integration covers a relatively wide temporal window. We also asked subjects to (...) explicitly judge whether the two features would belong to the same or to the different events. Unsurprisingly, synchrony judgments decreased with increasing asynchrony. Most importantly, feature binding was entirely unaffected by conscious experience: features were bound whether they were experienced as occurring together or as belonging to a separate events, suggesting that the conscious experience of unity is not a prerequisite for, or a direct consequence of binding. (shrink)

If we assume that the operation of each sense modality constitutes a different experience – a visual experience, an auditory experience, etc – we are faced with the problem of how those distinct experiences come together to form a unified perceptual encounter with the world. Michael Tye has recently argued that the best way to get around this problem is to deny altogether that there are such things as purely visual (and so forth) experiences. Here I aim to show not (...) simply that Tye’s proposed solution fails, but that its failure is highly instructive because it allows us to see that the transparency thesis, which lies at the heart of the case against qualia, and of most representationalist theories of experience, is more problematic than is often supposed. (shrink)