The Conscious Brain brings neuroscientific evidence to bear on enduring philosophical questions. Major philosophical and scientific theories of consciousness are surveyed, challenged, and extended.

Much as we would like to conceive empirical thought as rationally grounded in experience, pitfalls await anyone who tries to articulate this position, and ...

Neuropsychological findings used to motivate the "two visual systems" hypothesis have been taken to endanger a pair of widely accepted claims about spatial representation in conscious visual experience. The first is the claim that visual experience represents 3-D space around the perceiver using an egocentric frame of reference. The second is the claim that there is a constitutive link between the spatial contents of visual experience and the perceiver's bodily actions. In this paper, I review and assess three main sources (...) of evidence for the two visual systems hypothesis. I argue that the best interpretation of the evidence is in fact consistent with both claims. I conclude with some brief remarks on the relation between visual consciousness and rational agency. (shrink)

Recent work by philosophers of mind and psychology on nonconceptual content.

Milner and Goodale's influential account of the primate cortical visual streams involves a division of consciousness between them, for it is the ventral stream that has the responsibility for visual consciousness. Hence, the dorsal visual stream is a ‘zombie’ stream. In this article, I argue that certain information carried by the dorsal stream likely plays a central role in the egocentric spatial content of experience, especially the experience of visual spatial constancy. Thus, the dorsal stream contributes to a pervasive feature (...) of consciousness. (shrink)

I discuss Bermudez' minimalist approach to self-consciousness approvingly, connecting it with other positions in philosophy and trying to separate it from ideas about non-conceptual content.

I offer an explanation of how subjects are able to perceive the intrinsic spatial properties of objects, given that subjects always perceive from a particular location. The argument proceeds in two steps. First, I argue that a conception of space is necessary to perceive the intrinsic spatial properties of objects. This conception of space is spelled out by showing that perceiving intrinsic properties requires perceiving objects as the kind of things that are perceivable from other locations. Second, I show that (...) having such a conception of space presupposes that a subject represent her location in relation to perceived objects. More precisely the thesis is that a subject represents her location as the location from which she both perceives objects and would act in relation to objects were she to act. So I argue that perception depends on the capacity to know what it would be to act in relation to objects. (shrink)

Philosophers from Hume, Kant, and Wittgenstein to the recent realists and antirealists have sought to answer the question, What are concepts? This book provides a detailed, systematic, and accessible introduction to an original philosophical theory of concepts that Christopher Peacocke has developed in recent years to explain facts about the nature of thought, including its systematic character, its relations to truth and reference, and its normative dimension. Particular concepts are also treated within the general framework: perceptual concepts, logical concepts, and (...) the concept of belief are discussed in detail. The general theory is further applied in answering the question of how the ontology of concepts can be of use in classifying mental states, and in discussing the proper relation between philosophical and psychological theories of concepts. Finally, the theory of concepts is used to motivate a nonverificationist theory of the limits of intelligible thought. Peacocke treats content as broad rather than narrow, and his account is nonreductive and non-Quinean. Yet Peacocke also argues for an interactive relationship between philosophical and psychological theories of concepts, and he plots many connections with work in cognitive psychology. (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)

Many current neurophysiological, psychophysical, and psychological approaches to vision rest on the idea that when we see, the brain produces an internal representation of the world. The activation of this internal representation is assumed to give rise to the experience of seeing. The problem with this kind of approach is that it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness. An alternative proposal is made here. We propose that seeing is a way of (...) acting. It is a particular way of exploring the environment. Activity in internal representations does not generate the experience of seeing. The out- side world serves as its own, external, representation. The experience of seeing occurs when the organism masters what we call the gov- erning laws of sensorimotor contingency. The advantage of this approach is that it provides a natural and principled way of accounting for visual consciousness, and for the differences in the perceived quality of sensory experience in the different sensory modalities. Sev- eral lines of empirical evidence are brought forward in support of the theory, in particular: evidence from experiments in sensorimotor adaptation, visual “filling in,” visual stability despite eye movements, change blindness, sensory substitution, and color perception. (shrink)

This a review of Alva Noë's Action in Perception. It argues that a distinction should be made between the proposition that sensorimotor feedback is used in sensory perception and that perception is of sensorimotor features of the world. Noë fails to make this distinction.

How the various things that are said to have meaning—purpose, natural signs, linguistic signs, perceptions, and thoughts—are related to one another.

Perceptions "present" objects as red, as round, etc.-- in general as possessing some property. This is the "perceptual content" of the title, And the article attempts to answer the following question: what is a materialistically adequate basis for assigning content to what are, after all, neurophysiological states of biological organisms? The thesis is that a state is a perception that presents its object as "F" if the "biological function" of the state is to detect the presence of objects that are (...) "F". The theory contrasts with causal/informational theories, and with internalist theories, for example those which assign content on the basis of introspected feel. Its advantages are that it permits perceptual error while at the same time allowing content to be expressed in terms of external properties. The argument of the paper is illustrated throughout by examples from biology and computational psychology. (shrink)

How do rational minds make contact with the world? The empiricist tradition sees a gap between mind and world, and takes sensory experience, fallible as it is, to provide our only bridge across that gap. In its crudest form, for example, the traditional idea is that our minds consult an inner realm of sensory experience, which provides us with evidence about the nature of external reality. Notoriously, however, it turns out to be far from clear that there is any viable (...) conception of experience which allows it to do the job. The original problem is to show that thought is rationally constrained by external reality. If sensory experience is to provide the solution--in particular, if it is to provide the answer to sceptical challenges--it must therefore meet two criteria. First, it must itself be `receptive'--i.e., appropriately constrained by external reality. Second, it must be the kind of thing that can enter into a logical or rational relationship with belief--it must already be `conceptual,' in other words. In arguing against the idea that anything could serve both roles, Wilfred Sellars termed this conception of experience "the Myth of the Given.". (shrink)

An attempt is made to defend a general approach to the spatial content of perception, an approach according to which perception is imbued with spatial content in virtue of certain kinds of connections between perceiving organism's sensory input and its behavioral output. The most important aspect of the defense involves clearly distinguishing two kinds of perceptuo-behavioral skills—the formation of dispositions, and a capacity for emulation. The former, the formation of dispositions, is argued to by the central pivot of spatial content. (...) I provide a neural information processing interpretation of what these dispositions amount to, and describe how dispositions, so understood, are an obvious implementation of Gareth Evans' proposal on the topic. Furthermore, I describe what sorts of contribution are made by emulation mechanisms, and I also describe exactly how the emulation framework differs from similar but distinct notions with which it is often unhelpfully confused, such as sensorimotor contingencies and forward models. (shrink)

It is widely agreed that perceptual experience is a form of intentionality, i.e., that it has representational content. Many philosophers take this to mean that like belief, experience has propositional content, that it can be true or false. I accept that perceptual experience has intentionality; but I dispute the claim that it has propositional content. This claim does not follow from the fact that experience is intentional, nor does it follow from the fact that experiences are accurate or inaccurate. I (...) end by considering the relationship between this question and the question of whether experience has non-conceptual content. (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)

How should we characterize the functional role of conscious visual experience? In particular, how do the conscious contents of visual experience guide, bear upon, or otherwise inform our ongoing motor activities? According to an intuitive and (I shall argue) philosophically influential conception, the links are often quite direct. The contents of conscious visual experience, according to this conception, are typically active in the control and guidance of our fine-tuned, real-time engagements with the surrounding three-dimensional world. But this idea (which I (...) shall call the Assumption of Experience-Based Control) is hostage to empirical fortune. It is a hostage, moreover, whose safety is in serious doubt. Thus Milner and Goodale (1995) argue for a deep and abiding dissociation between the contents of conscious seeing, on the one hand, and the resources used for the on-line guidance of visuo-motor action, on the other. This ‘dual visual systems’ hypothesis, which finds many echoes in various other bodies of cognitive scientific research, poses a prima facie challenge to the Assumption of Experience-Based Control. More importantly, it provides (I shall argue) fuel for an alternative and philosophically suggestive account of the functional role of conscious visual experience. (shrink)

How should we characterize the functional role of conscious visual experience? In particular, how do the conscious contents of visual experience guide, bear upon, or otherwise inform our ongoing motor activities? According to an intuitive and philosophically influential conception, the links are often quite direct. The contents of conscious visual experience, according to this conception, are typically active in the control and guidance of our fine-tuned, real-time engagements with the surrounding three-dimensional world. But this idea is hostage to empirical fortune. (...) It is a hostage, moreover, whose safety is in serious doubt. Thus Milner and Goodale argue for a deep and abiding dissociation between the contents of conscious seeing, on the one hand, and the resources used for the on-line guidance of visuo-motor action, on the other. This ‘dual visual systems’ hypothesis, which finds many echoes in various other bodies of cognitive scientific research, poses a prima facie challenge to the Assumption of Experience-Based Control. More importantly, it provides fuel for an alternative and philosophically suggestive account of the functional role of conscious visual experience. (shrink)

Does the material basis of conscious experience extend beyond the boundaries of the brain and central nervous system? In Clark 2009 I reviewed a number of ‘enactivist’ arguments for such a view and found none of them compelling. Ward (2012) rejects my analysis on the grounds that the enactivist deploys an essentially world-involving concept of experience that transforms the argumentative landscape in a way that makes the enactivist conclusion inescapable. I present an alternative (prediction-and-generative-model-based) account that neatly accommodates all the (...) positive evidence that Ward cites on behalf of this enactivist conception, and that (I argue) makes richer and more satisfying contact with the full sweep of human experience. (shrink)

Tyler Burge presents an original study of the most primitive ways in which individuals represent the physical world. By reflecting on the science of perception and related psychological and biological sciences, he gives an account of constitutive conditions for perceiving the physical world, and thus aims to locate origins of representational mind.

This essay is a long one. It is not meant to be read in a single sitting. Its structure is as follows. In section I, I explicate perceptual anti-individualism. Section II centers on the two aspects of the representational content of perceptual states. Sections III and IV concern the nature of the empirical psychology of vision, and its bearing on the individuation of perceptual states. Section V shows how what is known from empirical psychology undermines disjunctivism and hence certain further (...) views that entail it, including naive realism. In Section VI, I raise a further point against disjunctivism. Section VII indicates how general reflection on perceptual perspective and epistemic ability supports the constraints from empirical psychology. It also explains how reflection on veridicality conditions, psychological explanation, and cognitive ability conspire to force recognition of the two kinds of representation mentioned in the preceding paragraph. In the Appendix, I criticize attempts to support disjunctivism. (shrink)

In this paper, I critically assess the enactive account of visual perception recently defended by Alva Noë (2004). I argue inter alia that the enactive account falsely identifies an object’s apparent shape with its 2D perspectival shape; that it mistakenly assimilates visual shape perception and volumetric object recognition; and that it seriously misrepresents the constitutive role of bodily action in visual awareness. I argue further that noticing an object’s perspectival shape involves a hybrid experience combining both perceptual and imaginative elements—an (...) act of what I call ‘make‐perceive’. (shrink)

It is natural to assume that the fine-grained and highly accurate spatial information present in visual experience is often used to guide our bodily actions. Yet this assumption has been challenged by proponents of the Two Visual Systems Hypothesis , according to which visuomotor programming is the responsibility of a “zombie” processing stream whose sources of bottom-up spatial information are entirely non-conscious . In many formulations of TVSH, the role of conscious vision in action is limited to “recognizing objects, selecting (...) targets for action, and determining what kinds of action, broadly speaking, to perform” . Our aim in this study is to show that the available evidence not only fails to support this dichotomous view but actually reveals a significant role for conscious vision in motor programming, especially for actions that require deliberate attention. (shrink)

It is now 25 years since Gareth Evans introduced the distinction between conceptual and nonconceptual content in The Varieties of Reference. This is a fitting time to take stock of what has become a complex and extended debate both within philosophy and at the interface between philosophy and psychology. Unfortunately, the debate has become increasingly murky as it has become increasingly ramified. Much of the contemporary discussion does not do full justice to the powerful theoretical tool originally proposed by Evans (...) and subsequently refined by theorists in the late 1980’s and early 1990’s – most effectively, I think, by Christopher Peacocke (particularly in his 1992). Even worse, significant parts of the discussion are somewhat confused. This paper makes a start on clarifying what I think ought to be the central issues in debates about nonconceptual content. I begin in §1 by pointing out how narrowly focused contemporary discussion is relative to Evans’s original discussion. We are not making as much use as we should of nonconceptual content as a tool for understanding subpersonal information processing and the complexities of its status relative to perception and thought at the personal level. In §2 I turn to what is the central focus of contemporary discussion, namely, the content of perception and identify a “master argument” for nonconceptualism based on the relation between conceptual capacities and capacities for perceptual discrimination. The aim of §3 is to clarify the relation between the claim that perception has nonconceptual content and some superficially similar claims discussed by philosophers of perception. Finally, in §4 I explain why the attention recently focused on what is sometimes called the state version of the nonconceptualist thesis seems to me to be misdirected. (shrink)

In _ Plato's Camera_, eminent philosopher Paul Churchland offers a novel account of how the brain constructs a representation -- or "takes a picture" -- of the universe's timeless categorical and dynamical structure. This construction process, which begins at birth, yields the enduring background conceptual framework with which we will interpret our sensory experience for the rest of our lives. But, as even Plato knew, to make singular perceptual judgments requires that we possess an antecedent framework of abstract categories to (...) which any perceived particular can be relevantly assimilated. How that background framework is assembled in the first place is the motivating mystery, and the primary target, of Churchland's book. Unexpectedly, this neurobiologically grounded account of human cognition also provides a systematic story of how such low-level epistemological activities are integrated within an enveloping framework of linguistic structures and regulatory mechanisms at the social level. As Churchland illustrates, this integration of cognitive mechanisms at several levels has launched the human race on an epistemological adventure denied to all other terrestrial creatures. (shrink)

The catastrophe of the eye -- A new view of seeing -- Applying the new view of seeing -- The illusion of seeing everything -- Some contentious points -- Towards consciousness -- Types of consciousness -- Phenomenal consciousness, raw feel, and why they're hard -- Squeeze a sponge, drive a porsche : a sensorimotor account of feel -- Consciously experiencing a feel -- The sensorimotor approach to color -- Sensory substitution -- The localization of touch -- The phenomenality plot -- (...) Consciousness. (shrink)

"Perception is not something that happens to us, or in us," writes Alva Noe. "It is something we do." In Action in Perception, Noe argues that perception and perceptual consciousness depend on capacities for action and thought — that ...

Self and World is an exploration of the nature of self-awareness. Quassim Cassam challenges the widespread and influential view that we cannot be introspectively aware of ourselves as objects in the world. In opposition to the views of many empiricist and idealistic philosophers, including Hume, Kant and Wittgenstein, he argues that the self is not systematically elusive from the perspective of self-consciousness, and that consciousness of our thoughts and experiences requires a sense of our thinking, experiencing selves as shaped, located, (...) and solid physical objects in a world of such objects. Awareness of oneself as a physical object involves forms of bodily self-awareness whose importance has seldom been properly acknowledged in philosophical accounts of the self and self-awareness. The conception of self-awareness defended in this book helps to undermins the idealist thesis that the self does not belong to the world, and also the claim that the existence of subjects or persons is only a derivative feature of reality. In the final part of the book, Cassam argues that the existence of persons is a substantial fact about the world, and that it is not possible to give a complete description of reality without claiming that persons exist. This clear, original, and challenging treatment of one of the deepest intellectual problems will demand the attention of all philosophers and cognitive scientists who are concerned with the self. (shrink)

" Biosemantics " was the title of a paper on mental representation originally printed in The Journal of Philosophy in 1989. It contained a much abbreviated version of the work on mental representation in Language Thought and Other Biological Categories. There I had presented a naturalist theory of intentional signs generally, including linguistic representations, graphs, charts and diagrams, road sign symbols, animal communications, the "chemical signals" that regulate the function of glands, and so forth. But the term " biosemantics " (...) has usually been applied only to the theory of mental representation. Let me first characterize a more general class of theories called "teleological theories of mental content" of which biosemantics is an example. Then I will discuss the details that distinguish biosemantics from other naturalistic teleological theories. (shrink)

The character of computational modelling of cognition depends on an underlying theory of representation. Classical cognitive science has exploited the syntax/semantics theory of representation that derives from logic. But this has had the consequence that the kind of psychological explanation supported by classical cognitive science is " _conceptualist_: " psychological phenomena are modelled in terms of relations that hold between concepts, and between the sensors/effectors and concepts. This kind of explanation is inappropriate for the Proper Treatment of Connectionism.

According to proponents of the sensorimotor contingency theory of perception (Hurley & Noë 2003, Noë 2004, O’Regan 2011), active control of camera movement is necessary for the emergence of distal attribution in tactile-visual sensory substitution (TVSS) because it enables the subject to acquire knowledge of the way stimulation in the substituting modality varies as a function of self-initiated, bodily action. This chapter, by contrast, approaches distal attribution as a solution to a causal inference problem faced by the subject’s perceptual systems. (...) Given all of the available endogenous and exogenous evidence available to those systems, what is the most probable source of stimulation in the substituting modality? From this perspective, active control over the camera’s movements matters for rather different reasons. Most importantly, it generates proprioceptive and efference-copy based information about the camera’s body-relative position necessary to make use of the spatial cues present in the stimulation that the subject receives for purposes of egocentric object localization. (shrink)

The purpose of this paper is to defend what I call the action-oriented coding theory (ACT) of spatially contentful visual experience. Integral to ACT is the view that conscious visual experience and visually guided action make use of a common subject-relative or 'egocentric' frame of reference. Proponents of the influential two visual systems hypothesis (TVSH), however, have maintained on empirical grounds that this view is false (Milner & Goodale, 1995/2006; Clark, 1999; 2001; Campbell, 2002; Jacob & Jeannerod, 2003; Goodale & (...) Milner, 2004). One main source of evidence for TVSH comes from behavioral studies of the comparative effects of size-contrast illusions on visual awareness and visuo- motor action. This paper shows that not only is the evidence from illusion studies inconclusive, there is a better, ACT-friendly interpretation of the evidence that avoids serious theoretical difficulties faced by TVSH. (shrink)

Alva Noë’s _Action in Perception _offers a provocative and vigorous defense of the thesis that vision is enactive: visual experience depends on dispositional motor responses. On this view, vision and action are inextricably bound. In this review, I argue against enactive perception. I raise objections to seven lines of evidence that appear in Noë’s book, and I indicate some reasons for thinking that vision can operate independently of motor responses. I conclude that the relationship between vision and action is causal, (...) not constitutive. I then address three other contentious hypotheses in the book. Noë argues that visual states are not pictorial; he argues that all perception is conceptual; and he argues that the external world makes a constitutive contribution to experience. I am unpersuaded by these arguments, and I offer reasons to resist Noë’s conclusions. (shrink)