In this paper, I argue that certain perceptual relations are represented in visual experience.

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 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)

Some philosophers have argued recently that the content of perception is either entirely or mainly non- conceptual. Much of the motivation for that view derives from theories of information processing, which are a modern version of ancient considerations about the causal processes underlying perception. The paper argues to the contrary that perception is essentially concept- dependent. While perception must have a structure derived from what is purely sensory, and is thereby dependent on processes involving information in the technical sense which (...) Gibson said amounted to structure, the information which perception provides about the world depends on the concepts which we have. (shrink)

Husserl's theory of perception is remarkable in several respects. For one thing, Husserl rigorously distinguishes the parts and properties of the act of consciousness - its content -from the parts and properties of the object perceived. Second, Husserl's repeated insistence that perceptual consciousness places its subject in touch with the perceived object itself, rather than some representation that does duty for it, vindicates the commonsensical and phenomenologically grounded belief that when a thing appears to us, it is precisely that thing, (...) rather than some other thing (its 'appearance'), that we perceive. Third, his distinction between empty and intuitive acts, and his descriptions of their complex interplay in perceptual consciousness, provides a way of making sense of the fact that an object can be perceived even when some of its parts and properties are not. Finally, his theory of perceptual acts as constituents of higher-order acts of fulfilment provides one of the few detailed accounts in the philosophical literature of how a perceptual experience can transform a mere thought into knowledge, despite the fact that the relation between perception and belief is not a logical or inferential one. Because Husserl's theory of perception is a serious candidate for truth, it is also a serious candidate for philosophical criticism. As such, in what follows I will treat it as a live force to be reckoned with rather than a historical curiosity. (shrink)

For Reid, the external senses have a “double province.” They give rise to both sensation and perception. This essay is about the relation of sensation and perception, a relation Reid’s sign theory of sensations describes. Drawing on Reid’s distinctions between general and particular principles of our constitution, relative and absolute conceptions, and original and acquired perception, the paper systematizes Reid’s sporadic comments on the sign theory. The aim is to offer an interpretation which reveals the overall structure, rationale and coherence (...) of Reid’s sign theory. (shrink)

Attention has been studied in cognitive psychology for more than half a century, but until recently it was largely neglected in philosophy. Now, however, attention has been recognized by philosophers of mind as having an important role to play in our theories of consciousness and of cognition. At the same time, several recent developments in psychology have led psychologists to foundational questions about the nature of attention and its implementation in the brain. As a result there has been a convergence (...) of interest in fundamental questions about attention. This volume presents the latest thinking from the philosophers and psychologists who are working at the interface between these two disciplines. Its fourteen chapters contain detailed philosophical and scientific arguments about the nature and mechanisms of attention; the relationship between attention and consciousness; the role of attention in explaining reference, rational thought, and the control of action; the fundamental metaphysical status of attention, and the details of its implementation in the brain. These contributions combine ideas from phenomenology, neuroscience, cognitive psychology, and philosophy of mind to further our understanding of this centrally important mental phenomenon, and to bring to light the foundational questions that any satisfactory theory of attention will need to address. (from OUP website). (shrink)

According to rich views of consciousness (e.g., James, Searle), we have a constant, complex flow of experience (or 'phenomenology') in multiple modalities simultaneously. According to thin views (e.g., Dennett, Mack and Rock), conscious experience is limited to one or a few topics, regions, objects, or modalities at a time. Existing introspective and empirical arguments on this issue (including arguments from 'inattentional blindness') generally beg the question. Participants in the present experiment wore beepers during everyday activity. When a beep sounded, they (...) were to take note of the conscious experience, if any, they were having at the last undisturbed moment immediately prior to the beep. Some participants were asked to report any experience they could remember. Others were asked simply to report whether there was visual experience or not (and if so, what it was). Still others were asked about experience in the far right visual field, or tactile experience, or tactile experience in the left foot. A majority of participants in the full experience and the visual conditions reported visual experience in every single sample. Tactile and peripheral visual experience were reported less often. However, the proper interpretation of these results is uncertain. (shrink)

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

This paper defends and develops the structuring account of conscious attention: attention is the conscious mental process of structuring one’s stream of consciousness so that some parts of it are more central than others. In the first part of the paper, I motivate the structuring account. Drawing on a variety of resources I argue that the phenomenology of attention cannot be fully captured in terms of how the world appears to the subject, as well as against an atomistic conception of (...) attention. In the second part of the paper, I show how the structuring account can be made precise: attention causes and causally sustains phenomenal relations to hold between the parts of the stream of consciousness; most importantly the relation of one part being peripheral to another. I end by pointing out consequences for both the scientific study of attention as well as for several areas of central philosophical interest. (shrink)

Arien Mack and Irvin Rock make the radical claim that there is no conscious perception of the visual world without attention to it.

Does attention alter appearance? This critical issue, debated for over a century, remains unsettled. From psychophysical evidence that covert attention affects early vision-it enhances contrast sensitivity and spatial resolution-and from neurophysiological evidence that attention increases the neuronal contrast sensitivity (contrast gain), one could infer that attention changes stimulus appearance. Surprisingly, few studies have directly investigated this issue. Here we developed a psychophysical method to directly assess the phenomenological correlates of attention in humans. We show that attention alters appearance; it boosts (...) the apparent stimulus contrast. These behavioral results are consistent with neurophysiological findings suggesting that attention changes the strength of a stimulus by increasing its 'effective contrast' or salience. (shrink)

This paper gives a brief presentation of adverbialism about attention, and explains some of the reasons why it gives an appealing account of attention's metaphysics.