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)

In Quentin Smith and Aleksander Jokic (eds.), Consciousness: New Philosophical Essays (OUP, 2002).

We agree with Block's basic hypothesis postulating the existence of phenomenal consciousness without cognitive access. We explain such states in terms of consciousness without top-down, endogenous attention and speculate that their correlates may be a coalition of neurons that are consigned to the back of cortex, without access to working memory and planning in frontal cortex.

We often feel that our perceptual experience is richer than what we can express. For instance, when flashed with a large set of letters, we feel that we can see them all, while we can report only a few. However, the nature of this subjective impression remains highly debated: while many favour a dissociation between two forms of consciousness , others contend that the richness of phenomenal experience is a mere illusion. Here we addressed this question with a classical partial-report (...) paradigm now modified to include unexpected items in the unreported parts of the stimuli. We show that even in the presence of unexpected pseudo-letters, participants still felt that there were only letters. Additionally, we show that this feeling reflects an illusion whereby participants reconstruct letters using partial letter-like information. We propose that the feeling of seeing emerges from the interplay between partially accessible information and expectations. (shrink)

Block tries to show that the results of the Sperling experiment lend support to the view that phenomenology outstrips cognitive accessibility. I argue that Block fails to make a compelling case for this general claim on the basis of the Sperling data.

Block proposes that phenomenal experience overflows conscious access. In contrast, we propose that conscious access overflows overt report. We argue that a theory of phenomenal experience cannot discard subjective report and that Block's examples of phenomenal relate to two different types of perception. We propose that conscious access is more than simply readout of a pre-existing phenomenal experience.

Abstract The subjectivity of conscious experience is a central feature of our mental life that puzzles philosophers of mind. Conscious mental representations are presented to me as mine, others remain unconscious. How can we make sense of the difference between them? Some representationalists (e.g. Tye) attempt to explain it in terms of non-conceptual intentional content, i.e. content for which one need not possess the relevant concept required in order to describe it. Hanna claims that Kant purports to explain the subjectivity (...) of conscious experience in this way. This paper examines this claim in some detail in the context of a more general criticism of this kind of attempt to explain subjectivity and proposes a different reading of Kant that also leads to an alternative account of subjectivity independent from content. (shrink)

I argue that the partial-report results Block cites do not establish that phenomenology overflows cognitive accessibility, as Block maintains. So, without additional argument, the mesh he sees between psychology and neuroscience is unsupported. I argue further that there is reason to hold, contra Block, that phenomenology does always involve some cognitive access to the relevant experience.

Block shows that we can consciously see a scene without being able to identify all the individual items in it. But in itself this fails to drive a wedge between phenomenology and access. Once we distinguish scene phenomenology from item phenomenology, the link between phenomenology and access is restored.

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.

. When I have a conscious experience of the sky, there is a bluish way it is like for me to have that experience. We may distinguish two aspects of this "bluish way it is like for me": the bluish aspect and the for-me aspect. Let us call the bluish aspect of the experience its qualitative character and the for-me aspect its subjective character . What is this elusive for-me-ness, or subjective character , of conscious experience? In this paper, I (...) examine six different attempts to account for subjective character in terms of the functional and representational properties of conscious experiences. After arguing against the first five, I defend the sixth. (shrink)

The dissociation Block provides between phenomenal and access consciousness (P-consciousness and A-consciousness) captures much of our intuition about conscious experience. However, it raises a major methodological puzzle, and is not uniquely supported by the empirical evidence. We provide an alternative interpretation based on the notion of levels of representation and partial awareness.

I briefly sketch a notion of generic phenomenology, and what I call the wave-collapse illusion to the effect that transitions from generic to detailed phenomenology are not noticed as phenomenal changes. Change blindness and inattentional blindness can be analyzed as cases where certain things are phenomenally present, but generically so.

The differences Block attempts to capture with his putative distinction between P-consciousness and A-consciousness are more directly and perspicuously handled in terms of differences in richness of content and degree of influence. Block's critiques, based on his misbegotten distinction, evaporate on closer inspection.

Little, Brown, 1992 Review by Glenn Branch on Jul 5th 1999 Volume: 3, Number: 27.

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)

The publication of this book is an event in the making. All over the world scientists, psychologists, and philosophers are waiting to read Antonio Damasio's new theory of the nature of consciousness and the construction of the self. A renowned and revered scientist and clinician, Damasio has spent decades following amnesiacs down hospital corridors, waiting for comatose patients to awaken, and devising ingenious research using PET scans to piece together the great puzzle of consciousness. In his bestselling Descartes' Error, Damasio (...) revealed the critical importance of emotion in the making of reason. Building on this foundation, he now shows how consciousness is created. Consciousness is the feeling of what happens-our mind noticing the body's reaction to the world and responding to that experience. Without our bodies there can be no consciousness, which is at heart a mechanism for survival that engages body, emotion, and mind in the glorious spiral of human life. A hymn to the possibilities of human existence, a magnificent work of ingenious science, a gorgeously written book, The Feeling of What Happens is already being hailed as a classic. (shrink)

Here, we argue that any neurobiological theory based on an experience/function division cannot be empirically confirmed or falsified and is thus outside the scope of science. A ‘perfect experiment’ illustrates this point, highlighting the unbreachable boundaries of the scientific study of consciousness. We describe a more nuanced notion of cognitive access that captures personal experience without positing the existence of inaccessible conscious states. Finally, we discuss the criteria necessary for forming and testing a falsifiable theory of consciousness.

Short commentary on a paper by Ned Block.

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)

We are material beings in a material world, but we are also beings who have experiences and feelings. How can these subjective states be just a matter of matter? To defend materialism, philosophical materialists have formulated what is sometimes called "the phenomenal-concept strategy," which holds that we possess a range of special concepts for classifying the subjective aspects of our experiences. In Consciousness Revisited, the philosopher Michael Tye, until now a proponent of the the phenomenal-concept strategy, argues that the strategy (...) is mistaken. A rejection of phenomenal concepts leaves the materialist with the task of finding some other strategy for defending materialism. Tye points to four major puzzles of consciousness that arise: How is it possible for Mary, in the famous thought experiment, to make a discovery when she leaves her black-and-white room? In what does the explanatory gap consist and how can it be bridged? How can the hard problem of consciousness be solved? How are zombies possible? Tye presents solutions to these puzzles -- solutions that relieve the pressure on the materialist created by the failure of the phenomenal-concept strategy. In doing so, he discusses and makes new proposals on a wide range of issues, including the nature of perceptual content, the conditions necessary for consciousness of a given object, the proper understanding of change blindness, the nature of phenomenal character and our awareness of it, whether we have privileged access to our own experiences, and, if we do, in what such access consists. (shrink)

Unlike the first English translation in 1974, this edition contains the text corresponding to Brentano's original 1874 edition.

within-field task as testing proceeded. (In any case, the two-field task is presumably a more difficult one than the one-field task. ...

Consciousness and Mind presents David Rosenthal's influential work on the nature of consciousness. Central to that work is Rosenthal's higher-order-thought theory of consciousness, according to which a sensation, thought, or other mental state is conscious if one has a higher-order thought that one is in that state. The first four essays develop various aspects of that theory. The next three essays present Rosenthal's homomorphism theory of mental qualities and qualitative consciousness, and show how that theory fits with and helps sustain (...) the HOT theory. A crucial feature of homomorphism theory is that it individuates and taxonomizes mental qualities independently of the way we're conscious of them, and indeed independently of our being conscious of them at all. So the theory accommodates the qualitative character not only of conscious sensations and perceptions, but also of those which fall outside our stream of consciousness. Rosenthal argues that, because this account of mental qualities makes no appeal to consciousness, it enables us to dispel such traditional quandaries as the alleged conceivability of undetectable quality inversion, and to disarm various apparent obstacles to explaining qualitative consciousness and understanding its nature. Six further essays build on the HOT theory to explain various important features of consciousness, among them the complex connections that hold in humans between consciousness and speech, the self-interpretative aspect of consciousness, and the compelling sense we have that consciousness is unified. Two of the essays, one an extended treatment of homomorphism theory, appear here for the first time. There is also a substantive introduction, which draws out the connections between the essays and highlights their implications. (shrink)

The contributions to this book are original articles, representing a cross-section of current philosophical work on consciousness and thereby allowing students and readers from other disciplines to acquaint themselves with the very latest debate, so that they can then pursue their own research interests more effectively. The volume includes a bibliography on consciousness in philosophy, cognitive science and brain research, covering the last 25 years and consisting of over 1000 entries in 18 thematic sections, compiled by David Chalmers and Thomas (...) Metzinger. (shrink)

Some mental events are conscious, some are unconscious. What is the difference between the two? Uriah Kriegel offers an answer. His aim is a comprehensive theory of the features that all and only conscious mental events have. The key idea is that consciousness arises when self-awareness and world-awareness are integrated in the right way. Conscious mental events differ from unconscious ones in that, whatever else they may represent, they always also represent themselves, and do so in a very specific way. (...) Subjective Consciousness is a fascinating new move forward towards a full understanding of the mind. (shrink)

Leading theorists examine the self-representational theory of consciousness as an alternative to the two dominant reductive theories of consciousness, the ..

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 ..

Over a long career, Libet has conducted experiments that have shown, in clear and concrete ways, how the brain produces conscious awareness.

In "The Quest for Consciousness," Caltech neuroscientist Christof Koch explores the biological basis of consciousness.

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)