Lycan not only uses the numerous arguments against materialism, and functionalist theories of mind in particular, to gain a more detailed positive view of the ..

In this provocative book, Fred Dretske argues that to achieve an understanding of the mind it is not enough to understand the biological machinery by means of...

Traditionally, perceptual experiences—for example, the experience of seeing a cat—were thought to have two quite distinct components. When one sees a cat, one’s experience is “about” the cat: this is the representational or intentional component of the experience. One’s experience also has phenomenal character: this is the sensational component of the experience. Although the intentional and sensational components at least typically go together, in principle they might come apart: the intentional component could be present without the sensational component or vice (...) versa. (shrink)

This introductory chapter attempts to clarify the philosophical, empirical, and theoretical bases on which a cognitive neuroscience approach to consciousness can be founded. We isolate three major empirical observations that any theory of consciousness should incorporate, namely (1) a considerable amount of processing is possible without consciousness, (2) attention is a prerequisite of consciousness, and (3) consciousness is required for some specific cognitive tasks, including those that require durable information maintenance, novel combinations of operations, or the spontaneous generation of intentional (...) behavior. We then propose a theoretical framework that synthesizes those facts: the hypothesis of a global neuronal workspace. This framework postulates that, at any given time, many modular cerebral networks are active in parallel and process information in an unconscious manner. An information becomes conscious, however, if the neural population that represents it is mobilized by top-down attentional amplification into a brain-scale state of coherent activity that involves many neurons distributed throughout the brain. The long-distance connectivity of these `workspace neurons' can, when they are active for a minimal duration, make the information available to a variety of processes including perceptual categorization, long-term memorization, evaluation, and intentional action. We postulate that this global availability of information through the workspace is what we subjectively experience as a conscious state. A complete theory of consciousness should explain why some cognitive and cerebral representations can be permanently or temporarily inaccessible to consciousness, what is the range of possible conscious contents, how they map onto specific cerebral circuits, and whether a generic neuronal mechanism underlies all of them. We confront the workspace model with those issues and identify novel experimental predictions. Neurophysiological, anatomical, and brain-imaging data strongly argue for a major role of prefrontal cortex, anterior cingulate, and the areas that connect to them, in creating the postulated brain-scale workspace. (shrink)

Amidst the many brain events evoked by a visual stimulus, which are specifically associated with conscious perception, and which merely reflect non-conscious processing? Several recent neuroimaging studies have contrasted conscious and non-conscious visual processing, but their results appear inconsistent. Some support a correlation of conscious perception with early occipital events, others with late parieto-frontal activity. Here we attempt to make sense of those dissenting results. On the basis of a minimal neuro-computational model, the global neuronal workspace hypothesis, we propose a (...) taxonomy which distinguishes between vigilance and access to conscious report, as well as between subliminal, preconscious and conscious processing. We suggest that these distinctions map onto different neural mechanisms, and that conscious perception is systematically associated with a sudden surge of parieto-frontal activity causing top-down amplification. (shrink)

Traditionally, perceptual experiences—for example, the experience of seeing a cat—were thought to have two quite distinct components. When one sees a cat, one’s experience is “about” the cat: this is the representational or intentional component of the experience. One’s experience also has phenomenal character: this is the sensational component of the experience. Although the intentional and sensational components at least typically go together, in principle they might come apart: the intentional component could be present without the sensational component or vice (...) versa. (shrink)

Short commentary on a paper by Ned Block.

Inference-to-best-explanation from psychological evidence supports the view that phenomenal consciousness in perceptual exposures occurs before limited aspects of that consciousness are retained in working memory. Independently of specific neurological theory, psychological considerations indicate that machinery producing phenomenal consciousness is independent of machinery producing working memory, hence independent of access to higher cognitive capacities.

endorsed one kind of inverted spectrum hypothesis and rejected another. This paper argues that the kind of inverted spectrum hypothesis that Wittgenstein endorsed is the thin end of the wedge that precludes a Wittgensteinian critique of the kind of inverted spectrum hypothesis he rejected. The danger of the dangerous kind is that it provides an argument for qualia, where qualia are contents of experiential states which cannot be fully captured in natural language. I will pinpoint the difference between the innocuous (...) and dangerous scenarios that matters for the argument for qualia, give arguments in favor of the coherence and possibility of the dangerous scenario, and try to show that some standard arguments against inverted spectra are ineffective against the version of the dangerous scenario I will be advocating. The leading idea of the paper is that an argument for qualia based on spectrum inversion does not require that the inversion be behaviorally indistinguishable. At one crucial point, I will rely on a less controversial version of an argument I gave in Block. Wittgenstein's views provide a convenient starting point for a paper that is much more about qualia than about Wittgenstein. (shrink)

One of the most important issues concerning the foundations ofconscious perception centerson thequestion of whether perceptual consciousness is rich or sparse. The overflow argument uses a form of ‘iconic memory’ toarguethatperceptual consciousnessisricher (i.e.,has a higher capacity) than cognitive access: when observing a complex scene we are conscious of more than we can report or think about. Recently, the overflow argumenthas been challenged both empirically and conceptually. This paper reviews the controversy, arguing that proponents of sparse perception are committed to the (...) postulation of (i) a peculiar kind of generic conscious representation that has no independent rationale and (ii) an unmotivated form of unconscious representation that in some cases conflicts with what we know about unconscious representation. (shrink)

Consciousness is a mongrel concept: there are a number of very different "consciousnesses." Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access-consciousness, by contrast, is availability for use in reasoning and rationally guiding speech and action. These concepts are often partly or totally conflated, with bad results. This target article uses as an example a form of reasoning about a function of "consciousness" based on (...) the phenomenon of blindsight. Some information about stimuli in the blind field is represented in the brains of blindsight patients, as shown by their correct "guesses," but they cannot harness this information in the service of action, and this is said to show that a function of phenomenal consciousness is somehow to enable information represented in the brain to guide action. But stimuli in the blind field are BOTH access-unconscious and phenomenally unconscious. The fallacy is: an obvious function of the machinery of access-consciousness is illicitly transferred to phenomenal consciousness. (shrink)

How can we disentangle the neural basis of phenomenal consciousness from the neural machinery of the cognitive access that underlies reports of phenomenal consciousness? We can see the problem in stark form if we ask how we could tell whether representations inside a Fodorian module are phenomenally conscious. The methodology would seem straightforward: find the neural natural kinds that are the basis of phenomenal consciousness in clear cases when subjects are completely confident and we have no reason to doubt their (...) authority, and look to see whether those neural natural kinds exist within Fodorian modules. But a puzzle arises: do we include the machinery underlying reportability within the neural natural kinds of the clear cases? If the answer is ‘Yes’, then there can be no phenomenally conscious representations in Fodorian modules. But how can we know if the answer is ‘Yes’? The suggested methodology requires an answer to the question it was supposed to answer! The paper argues for an abstract solution to the problem and exhibits a source of empirical data that is relevant, data that show that in a certain sense phenomenal consciousness overflows cognitive accessibility. The paper argues that we can find a neural realizer of this overflow if assume that the neural basis of phenomenal consciousness does not include the neural basis of cognitive accessibility and that this assumption is justified by the explanations it allows. (shrink)

This article concerns the interplay between two issues that involve both philosophy and neuroscience: whether the content of phenomenal consciousness is 'rich' or 'sparse', whether phenomenal consciousness goes beyond cognitive access, and how it would be possible for there to be evidence one way or the other.

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

Conscious experience is one of the most difficult and thorny problems in psychological science. Its study has been neglected for many years, either because it was thought to be too difficult, or because the relevant evidence was thought to be poor. Bernard Baars suggests a way to specify empirical constraints on a theory of consciousness by contrasting well-established conscious phenomena - such as stimulus representations known to be attended, perceptual, and informative - with closely comparable unconscious ones - such as (...) stimulus representations known to be preperceptual, unattended, or habituated. Adducing data to show that consciousness is associated with a kind of global workplace in the nervous system, and that several brain structures are known to behave in accordance with his theory, Baars helps to clarify many difficult problems. (shrink)

Representationalism is a thesis about the phenomenal character of experiences, about their immediate subjective ‘feel’.1 At a minimum, the thesis is one of supervenience: necessarily, experiences that are alike in their representational contents are alike in their phenomenal character. So understood, the thesis is silent on the nature of phenomenal character. Strong or pure representationalism goes further. It aims to tell us what phenomenal character is. According to the theory developed in Tye 1995, phenomenal character is one and the same (...) as representational content that meets certain further conditions. One very important motivation for this theory is the so-called ? transparency of experience.? The purpose of this paper is to elucidate the appeal to transparency more carefully than has been done hithertofore, to make some remarks about the introspective awareness of experience in light of this appeal, and to consider one problem case for transparency at some length, that of blurry vision. Along the way, I shall also address some of the remarks Stephen Leeds makes in his essay on transparency. (shrink)

In 1995, in my book, Ten Problems of Consciousness, I proposed a version of the theory of phenomenal consciousness now known as representationalism. The present book, in part, consists of a further development of that theory along with replies to common objections. It is also concerned with two prominent challenges for any reductive theory of consciousness: the explanatory gap and the knowledge argument. In addition, it connects representationalism with two more general issues: the nature of color and the location of (...) the phylogenetic dividing line between those creatures that are phenomenally conscious and those that are not. (shrink)

1. Introduction In ‘The Refutation of Idealism’, G.E.Moore observed that, "when we try to introspect the sensation of blue, all we can see is the blue: the other element is as if it were diaphanous" (1922; p.25). Many philosophers, but Gilbert Harman (1990, 1996) in particular, have suggested that this observation forms the basis of an argument against qualia, usually called the argument from diaphanousness or transparency.1 But even its friends concede that it is none too clear what the argument (...) from diaphanousness—as I will call it—is (Tye 2000; p.45).2 The purpose of this paper is to formulate the argument, and to assess its merits. My conclusion will be that qualia realists have little to fear from the argument—provided both qualia and diaphanousness are properly understood. (shrink)

Introduction This book is about the nature of the content of psychological states. Examples of psychological states with content are: believing today is a ...

Can we ever experimentally disentangle phenomenal consciousness from the cognitive accessibility inherent to conscious reports? In this commentary, we suggest that (1) Block's notion of phenomenal consciousness remains intractably entangled with the need to obtain subjective reports about it; and (2) many experimental paradigms suggest that the intuitive notion of a rich but non-reportable phenomenal world is, to a large extent illusory – in a sense that requires clarification.

The transparency argument concludes that we're directly aware of external properties and not directly aware of the properties of experience. Focusing on the presentation used by Michael Tye (2002) I contend that the argument requires experience to have content that it cannot plausibly have. I attribute the failure to a faulty account of the transparency phenomenon and conclude by suggesting an alternative understanding that is independently plausible, is not an error-theory and yet renders the transparency of experience compatible with mental-paint (...) style views. (shrink)

" In Being No One, Metzinger, a German philosopher, draws strongly on neuroscientific research to present a representationalist and functional analysis of...

I explore the implications of recognizing two forms of access that might be constitutively related to phenomenal consciousness. I argue, in support of Block, that we don't have good reason to think that the link to reporting mechanisms is the kind of access that distinguishes an experience from a mere state.

Intuitions about the transparency of experience have recently begun to play a key role in the debate about qualia. Specifically, such intuitions have been used by representationalists to support their view that the phenomenal character of our experience can be wholly explained in terms of its intentional content.[i] But what exactly does it mean to say that experience is transparent? In my view, recent discussions of transparency leave matters considerably murkier than one would like. As I will suggest, there is (...) reason to believe that experience is not transparent in the way that representationalism requires. Although there is a sense in which experience can be said to be transparent, transparency in this sense does not give us any particular motivation for representationalism—or at least, not the pure or strong representationalism that it is usually invoked to support. (shrink)

I first argue that some of Block's formulations may misleadingly suggest that the function of mechanisms of so-called cognitive accessibility is to make one aware, not of visible features of the visible world, but of one's own psychological life. I then ask whether Block's view of phenomenology in the present target article is consistent with his endorsement of non-representationalism elsewhere.

This paper is concerned with the question of whether mature human experience is thoroughly conceptual, or whether it involves non-conceptual elements or layers. It has two central goals. The first goal is methodological. It aims to establish that that question is, to a large extent, an empirical question. The question cannot be answered by appealing to purely a priori and transcendental considerations. The second goal is to argue, inter alia by relying on empirical findings, that the view known as ‘state-conceptualism’ (...) is false. We will argue that our experiences do involve non-conceptual elements. That is, a subject may enjoy an experience with a particular phenomenal aspect, without possessing the concept needed for the specification of the content of that aspect, and moreover, without being able to acquire that concept upon having that experience. (shrink)

A further development of Tye's theory of phenomenal consciousness along with replies to common objections.

An argument that there are perceptual mechanisms that retrieve information in cognitively and conceptually unmediated ways and that this sheds light on various ...

The distinction between access consciousness and phenomenal consciousness is a subject of intensive debate. According to one view, visual experience overflows the capacity of the attentional and working memory system: We see more than we can report. According to the opposed view, this perceived richness is an illusion—we are aware only of information that we can subsequently report. This debate remains unresolved because of the inevitable reliance on report, which is limited in capacity. To bypass this limitation, this study utilized (...) color diversity—a unique summary statistic—which is sensitive to detailed visual information. Participants were shown a Sperling-like array of colored letters, one row of which was precued. After reporting a letter from the cued row, participants estimated the color diversity of the noncued rows. Results showed that people could estimate the color diversity of the noncued array without a cost to letter report, which suggests that color diversity is registered automatically, outside focal attention, and without consuming additional working memory resources. (shrink)