Because it is unclear how a nonconscious stimulus is cognitively processed, there is uncertainty concerning variables that modulate the processing. In this context recent findings of a set of neuroimaging experiments are important. These findings suggest that conscious and nonconscious stimuli activate same areas of the brain during performance of a similar task. Further, different areas are activated when a task is performed with or without awareness of processing. It appears that the neural network involved in cognitive processing depends on (...) the awareness of processing rather than awareness of perception. Since conscious and nonconscious cognitive processing use separate neural networks, each processing is modulated by different variables. Attention modulates most conscious cognitive processing and most, but not all, nonconscious processing is attention dependent. Nonconscious tasks that require attentional resources, with or without conscious awareness, are processed using the attention dependent system. Further, because attention dependent and attention independent tasks are processed by separate neural networks, the cognitive processing and modulating variables can be understood better if cognitive tasks are defined as attention dependent or attention independent, rather than conscious or nonconscious. (shrink)

This is a bibliography of books and articles on consciousness in philosophy, cognitive science, and neuroscience over the last 30 years. There are three main sections, devoted to monographs, edited collections of papers, and articles. The first two of these sections are each divided into three subsections containing books in each of the main areas of research. The third section is divided into 12 subsections, with 10 subject headings for philosophical articles along with two additional subsections for articles in cognitive (...) science and neuroscience. Of course the division is somewhat arbitrary, but I hope that it makes the bibliography easier to use. This bibliography has first been compiled by Thomas Metzinger and David Chalmers to appear in print in two philosophical anthologies on conscious experience . From 1995 onwards it has been continuously updated by Thomas Metzinger, and now is freely available as a PDF-, RTF-, or HTML-file. This bibliography mainly attempts to cover the Anglo-Saxon and German debates, in a non-annotated, fully formatted way that makes it easy to "cut and paste" from the original file. To a certain degree this bibliography also contains items in other languages than English and German - all submissions in other languages are welcome. Last update of current version: July 13th, 2001. (shrink)

A number of ways of taxonomizing human learning have been proposed. We examine the evidence for one such proposal, namely, that there exist independent explicit and implicit learning systems. This combines two further distinctions, (1) between learning that takes place with versus without concurrent awareness, and (2) between learning that involves the encoding of instances (or fragments) versus the induction of abstract rules or hypotheses. Implicit learning is assumed to involve unconscious rule learning. We examine the evidence for implicit learning (...) derived from subliminal learning, conditioning, artificial grammar learning, instrumental learning, and reaction times in sequence learning. We conclude that unconscious learning has not been satisfactorily established in any of these areas. The assumption that learning in some of these tasks (e.g., artificial grammar learning) is predominantly based on rule abstraction is questionable. When subjects cannot report the rules that govern stimulus selection, this is often because their knowledge consists of instances or fragments of the training stimuli rather than rules. In contrast to the distinction between conscious and unconscious learning, the distinction between instance and rule learning is a sound and meaningful way of taxonomizing human learning. We discuss various computational models of these two forms of learning. (shrink)

Few contemporary researchers in psychology, philosophy, and the cognitive sciences have any doubt about whether mental phenomena occur without being conscious. There is extensive and convincing clinical and experimental evidence for the existence of thoughts, desires, and related mental states that aren’t conscious. We characterize thoughts, desires, intentions, expectations, hopes, and many other mental states in terms of the things they are about and, more fully, in terms of their content, as captured by a sentence nominalization, such as a clause (...) beginning with the word ‘that’. The philosophical literature follows Franz Brentano’s adaptation of Thomist terminology in referring to all such states as intentional states. But there is another type of mental phenomena, which lack intentionality and whose mental nature consists instead of some qualitative feature. These states include bodily sensations, such as aches and pains, and perceptual states, such as visual sensations of color and tactile sensations of heat and cold. And these states all exhibit some mental quality or another, such as the mental quality distinctive of pain or the mental quality of red or blue.1 And even theorists who acknowledge that intentional states can and do occur without being conscious have sometimes insisted that qualitative states cannot. There is, according to these theorists, nothing to a state’s being qualitative or exhibiting some mental quality unless that state is conscious – unless it is, as we might metaphorically say, “lighted up”. It’s striking that Freud himself seems to have adopted this double standard toward the two types of mental state. In his metapsychological paper, “The Unconscious”, for example, he writes that “all the categories which we employ to describe conscious mental acts, such as ideas, purposes, resolutions, and so forth, can be applied to [unconscious mental occurrences]” (Freud 1915e, p. 168). But he seems here to have in.. (shrink)

A number of ways of taxonomizing human learning have been proposed. We examine the evidence for one such proposal, namely, that there exist independent explicit and implicit learning systems. This combines two further distinctions, between learning that takes place with versus without concurrent awareness, and between learning that involves the encoding of instances versus the induction of abstract rules or hypotheses. Implicit learning is assumed to involve unconscious rule learning. We examine the evidence for implicit learning derived from subliminal learning, (...) conditioning, artificial grammar learning, instrumental learning, and reaction times in sequence learning. We conclude that unconscious learning has not been satisfactorily established in any of these areas. The assumption that learning in some of these tasks is predominantly based on rule abstraction is questionable. When subjects cannot report the “implicitly learned” rules that govern stimulus selection, this is often because their knowledge consists of instances or fragments of the training stimuli rather than rules. In contrast to the distinction between conscious and unconscious learning, the distinction between instance and rule learning is a sound and meaningful way of taxonomizing human learning. We discuss various computational models of these two forms of learning. (shrink)

Seamon, Luo, and Gallo reported evidence that nonconscious processes could produce false recognition in a converging-associates task, whereby subjects falsely remember a nonstudied lure after studying a list of related words . Zeelenberg, Plomp, and Raaijmakers failed to observe this false recognition effect when list word recognition was at chance. We critically evaluate the evidence for nonsconscious processing and report the results of a new experiment designed to overcome previous methodological limitations. Consistent with Seamon et al., we found that conscious (...) activation of a related lure during study was not necessary for its subsequent recognition; consistent with Zeelenberg et al., we found no evidence for recognition of related lures under conditions where there was no memory for studied words. It is currently unknown whether conscious recollection of the studied items is necessary for false recognition or if nonconscious activation of the lure is sufficient. (shrink)

Legally blind participants were able to identify a visual stimulus attribute in the absence of consciously identifying its presence. Specifically, participants—with their corrective lenses removed—correctly guessed the hour-hand position above chance on a clockface shown on a computer screen. This occurred both when presented in a 1-clockface display , as well as when shown a display containing 4 clockfaces , in which only 1 face contained a hand. Even more striking, hand identification accuracy in the 4-clockface condition was comparable whether (...) the clockface containing the hand was or was not correctly identified. That legally blind individuals are capable of identifying stimulus attributes without conscious awareness provides an additional vehicle for exploring implicit perception. Consistent with previous research, the visualsystem can apparently cope with degraded visual input through information available through a secondary pathway via the superior colliculi. (shrink)

Reingold and MerikleÕs (1988, 1990) critique of the classic dissociation paradigm identified several issues as inherent problems that severely undermine the utility of this paradigm. Erdelyi (2004) extending his prior analysis (Erdelyi, 1985, 1986) points out several additional factors that may complicate the interpretation of empirically obtained dissociations. The goal of the present manuscript is to further discuss some of these commonly neglected interpretive difficulties. Ó 2003 Elsevier Inc. All rights reserved.

This chapter presents an overview of several recent developments in vision science, and outlines some of their implications for the management of visual attention in graphic displays. These include ways of sending attention to the right item at the right time, techniques to improve attentional efficiency, and possibilities for offloading some of the processing typically done by attention onto nonattentional mechanisms. In addition it is argued that such techniques not only allow more effective use to be made of visual attention, (...) but also open up new possibilities for human-machine interaction. (shrink)

consciousness. Such unconscious processing always " Cambridge, UK " tends to re?ect habitual or strong responses. From this.

This essay is a sustained attempt to bring new light to some of the perennial problems in philosophy of mind surrounding phenomenal consciousness and introspection through developing an account of sensory and phenomenal concepts. Building on the information-theoretic framework of Dretske (1981), we present an informational psychosemantics as it applies to what we call sensory concepts, concepts that apply, roughly, to so-called secondary qualities of objects. We show that these concepts have a special informational character and semantic structure that closely (...) tie them to the brain states realizing conscious qualitative experiences. We then develop an account of introspection which exploits this special nature of sensory concepts. The result is a new class of concepts, which, following recent terminology, we call phenomenal concepts: these concepts refer to phenomenal experience itself and are the vehicles used in introspection. On our account, the connection between sensory and phenomenal concepts is very tight: it consists in different semantic uses of the same cognitive structures underlying the sensory concepts, such as the concept of red. Contrary to widespread opinion, we show that information theory contains all the resources to satisfy internalist intuitions about phenomenal consciousness, while not offending externalist ones. A consequence of this account is that it explains and predicts the so-called conceivability arguments against physicalism on the basis of the special nature of sensory and phenomenal concepts. Thus we not only show why physicalism is not threatened by such arguments, but also demonstrate its strength in virtue of its ability to predict and explain away such arguments in a principled way. However, we take the main contribution of this work to be what it provides in addition to a response to those conceivability arguments, namely, a substantive account of the interface between sensory and conceptual systems and the mechanisms of introspection as based on the special nature of the information flow between them. (shrink)

It is often assumed that perceptual experience provides evidence about the external world. But much perception can occur unconsciously, as in cases of masked priming or blindsight. Does unconscious perception provide evidence as well? Many theorists maintain that it cannot, holding that perceptual experience provides evidence in virtue of its conscious character. Against such views, I challenge here both the necessity and, perhaps more controversially, the sufficiency of consciousness for perception to provide evidence about the external world. In addition to (...) motivating and defending the idea that unconscious perception can and does often provide evidence, I observe that whether or not perceptual phenomenology is relevant to the evidentiary status of perception depends on the nature of consciousness. And I argue that a well-supported theory of consciousness—higher-order thought theory—invites a striking conclusion: that perceptual phenomenology is not on its own sufficient to provide for evidence of the external world. (shrink)

This article discusses how sequential sampling models can be integrated in a cognitive architecture. The new theory Retrieval by Accumulating Evidence in an Architecture (RACE/A) combines the level of detail typically provided by sequential sampling models with the level of task complexity typically provided by cognitive architectures. We will use RACE/A to model data from two variants of a picture–word interference task in a psychological refractory period design. These models will demonstrate how RACE/A enables interactions between sequential sampling and long-term (...) declarative learning, and between sequential sampling and task control. In a traditional sequential sampling model, the onset of the process within the task is unclear, as is the number of sampling processes. RACE/A provides a theoretical basis for estimating the onset of sequential sampling processes during task execution and allows for easy modeling of multiple sequential sampling processes within a task. (shrink)

The traditional model of human cognition (TMHC) postulates an ontological and/or structural gap between conscious and unconscious mental representations. By and large, it sees higher-level mental processes as commonly conceptual or symbolic in nature and therefore conscious, whereas unconscious, lower-level representations are conceived as non-conceptual or sub-symbolic. However, experimental evidence belies this model, suggesting that higher-level mental processes can be, and often are, carried out in a wholly unconscious way and/or without conceptual representations, and that these can be processed unconsciously. (...) This entails that the TMHC, as well as the theories on mental representation it motivates and that in turn support it, is wrong. (shrink)

To which extent is it justified to adopt Kant as a godfather of cognitive science? To prepare the stage for an answer of this question, we need to set aside Kant’s general transcendental approach to the mind which is radically anti-empiricist and instead turn our attention to his specific topics and claims regarding the mind which are often not focus of Kant’s epistemological investigations. If someone is willing to take this stance, it turns out that there are many bridges connecting (...) Kant with contemporary cognitive science. We investigate possible bridges suggested in the literature between some of Kant’s central claims about consciousness, mental content, and functions of mind, and some specific treatments of these topics in contemporary philosophy of mind and cognitive science. While doing so, we offer additional arguments for some proposed bridges, reconstruct others and completely destroy still other bridges by demonstrating that some suggested links between Kant and cognitive science remain only apparent. (shrink)

In a series of three experiments, we explored the nature of implicit representations in change blindness . Using 3 × 3 letter arrays, we asked subjects to locate changes in paired arrays separated by 80 ms ISIs, in which one, two or three letters of a row in the second array changed. In one testing version, a tone followed the second array, signaling a row for partial report . In the other version, no PR was required. After Ss reported whether (...) a change had been detected and the PR had been completed , they were asked to identify a degraded letter trigram that was either novel, or from a previously shown row . Our findings indicate that when CB occurs, both the pre-change and post-change stimulus information primes despite its unavailability to consciousness. Surprisingly, findings also indicate that when change detection occurs only the post-change information primes. (shrink)

The aim of this paper is to argue that what I call the simple theory of introspection can be extended to account for our introspective knowledge of what we believe as well as what we consciously experience. In section one, I present the simple theory of introspection and motivate the extension from experience to belief. In section two, I argue that extending the simple theory provides a solution to Moore’s paradox by explaining why believing Moorean conjunctions always involves some degree (...) of irrationality. In section three, I argue that it also solves the puzzle of transparency by explaining why it’s rational to answer the question whether one believes that p by answering the question whether p. Finally, in section four, I defend the simple theory against objections by arguing that self-knowledge constitutes an ideal of rationality. (shrink)

The same-order representation theory of consciousness holds that conscious mental states represent both the world and themselves. This complex representational structure is posited in part to avoid a powerful objection to the more traditional higher-order representation theory of consciousness. The objection contends that the higher-order theory fails to account for the intimate relationship that holds between conscious states and our awareness of them--the theory 'divides the phenomenal labor' in an illicit fashion. This 'failure of intimacy' is exposed by the possibility (...) of misrepresentation by higher-order states. In this paper, I argue that despite appearances, the same-order theory fails to avoid the objection, and thus also has troubles with intimacy. (shrink)

Consciousness is central to our lived experience. It is unsurprising, then, that the topic has captivated many students, neuroscientists, philosophers, and other theorists working in cognitive science. But consciousness may seem especially difficult to explain. This is in part because the term “consciousness” has been used in many different ways. The goal of this chapter is to explore several kinds of consciousness: what theorists have called “creature,” “phenomenal,” “access,” “state,” “transitive,” “introspective,” and “self” consciousness. The basic distinctions among these kinds (...) of consciousness are described in Section 1. Section 2 raises potential challenges for explaining these varieties of consciousness and describes a few current theories of them. Section 3 closes the chapter by exploring directions for future work in the cognitive science of consciousness. Along the way, some of the possible interrelationships among these kinds of consciousness are discussed. (shrink)

Some theorists have recently raised doubts about much of the experimental evidence purporting to demonstrate the existence of unconscious perception. In our (2019) in this journal, we argued some of these considerations are not decisive. Phillips (forthcoming a) replies thoughtfully to our paper, concluding that he is unconvinced by our arguments. Phillips maintains that the view that perception is invariably conscious remains, as he puts it, the “default” hypothesis both within the folk understanding and experimental study of perception. There is (...) much to agree with in Phillips’ piece, but there remain some substantive points of disagreement, which we outline here. (shrink)

O'Brien & Opie's (O&O's) theory demands a view of unconscious processing that is incompatible with virtually all current PDP models of neural activity. Relative to the alternatives, the theory is closer to an AI than a parallel distributed processing (PDP) perspective, and its treatment of phenomenology is ad hoc. It raises at least one important question: Could features of network relaxation be the “switch” that turns an unconscious into a conscious network?

More often than not, theories of belief and of belief ascription restrict themselves to conscious beliefs, thus obliterating a vast part of our mental life and offering extremely incomplete, unrealistic theories. Indeed, conscious beliefs are the exception, not the rule, as far as human doxastic states are concerned, and a naturalistic, realistic theory of knowledge that aspires to completeness has to take unconscious beliefs into consideration. This paper is the elaboration of such a theory of belief.

I examine the phenomenon of implicit learning, the process by which knowledge about the rule-governed complexities of the stimulus environment is acquired independently of conscious attempts to do so. Our research with the two seemingly disparate experimental paradigms of synthetic grammar learning and probability learning, is reviewed and integrated with other approaches to the general problem of unconscious cognition. The conclusions reached are as follows: Implicit learning produces a tacit knowledge base that is abstract and representative of the structure of (...) the environment; such knowledge is optimally acquired independently of conscious efforts to learn; and it can be used implicitly to solve problems and make accurate decisions about novel stimulus circumstances. Various epistemological issues and related problems such as intuition, neuroclinical disorders of learning and memory, and the relationship of evolutionary processes to cognitive science are also discussed. (shrink)

When cognitive scientists apply computational theory to the problem of phenomenal consciousness, as many of them have been doing recently, there are two fundamentally distinct approaches available. Either consciousness is to be explained in terms of the nature of the representational vehicles the brain deploys; or it is to be explained in terms of the computational processes defined over these vehicles. We call versions of these two approaches _vehicle_ and _process_ theories of consciousness, respectively. However, while there may be space (...) for vehicle theories of consciousness in cognitive science, they are relatively rare. This is because of the influence exerted, on the one hand, by a large body of research which purports to show that the explicit representation of information in the brain and conscious experience are _dissociable_, and on the other, by the _classical_ computational theory of mind – the theory that takes human cognition to be a species of symbol manipulation. But two recent developments in cognitive science combine to suggest that a reappraisal of this situation is in order. First, a number of theorists have recently been highly critical of the experimental methodologies employed in the dissociation studies – so critical, in fact, it’s no longer reasonable to assume that the dissociability of conscious experience and explicit representation has been adequately demonstrated. Second, classicism, as a theory of human cognition, is no longer as dominant in cognitive science as it once was. It now has a lively competitor in the form of _connectionism; _and connectionism, unlike classicism, does have the computational resources to support a robust vehicle theory of consciousness. In this paper we develop and defend this connectionist vehicle theory of consciousness. It takes the form of the following simple empirical hypothesis: _phenomenal experience consists in the explicit_ _representation of information in neurally realized PDP networks_.. (shrink)

While Chomsky subscribes to methodological naturalism, he rejects both metaphysical naturalism and an externalist conception of meaning. This chapter explores some of Chomsky's grounds for rejecting both metaphysical naturalism and meaning externalism, in particular his peculiar attitude towards ontological physicalism and his arguments for an internalist approach to meaning.

The implicit-explicit distinction is applied to knowledge representations. Knowledge is taken to be an attitude towards a proposition which is true. The proposition itself predicates a property to some entity. A number of ways in which knowledge can be implicit or explicit emerge. If a higher aspect is known explicitly then each lower one must also be known explicitly. This partial hierarchy reduces the number of ways in which knowledge can be explicit. In the most important type of implicit knowledge, (...) representations merely reflect the property of objects or events without predicating them of any particular entity The dearest cases of explicit knowledge of a fact are representations of one's own attitude of knowing that fact. These distinctions are discussed in their relationship to similar distinctions such as procedural-declarative, conscious unconscious, verbalizable-nonverbalizable, direct-indirect tests, and automatic voluntary control. This is followed by an outline of how these distinctions can be used to integrate and relate the often divergent uses of the implicit-explicit distinction in different research areas. We illustrate this for visual perception, memory, cognitive development, and artificial grammar learning. (shrink)

In this paper, I offer an account of the dependence relation between perception of change and the subjective flow of time that is consistent with some extant empirical evidence from priming by unconscious change. This view is inspired by the one offered by William James, but it is articulated in the framework of contemporary functionalist accounts of mental qualities and higher-order theories of consciousness. An additional advantage of this account of the relationship between perception of change and subjective time is (...) that is makes sense of instances where we are not consciously aware of changes but still experience the flow of time. (shrink)

Most ?theories of consciousness? are based on vague speculations about the properties of conscious experience. We aim to provide a more solid basis for a science of consciousness. We argue that a theory of consciousness should provide an account of the very processes that allow us to acquire and use information about our own mental states ? the processes underlying introspection. This can be achieved through the construction of information processing models that can account for ?Type-C? processes. Type-C processes can (...) be specified experimentally by identifying paradigms in which awareness of the stimulus is necessary for an intentional action. The Shallice (1988b) framework is put forward as providing an initial account of Type-C processes, which can relate perceptual consciousness to consciously performed actions. Further, we suggest that this framework may be refined through the investigation of the functions of prefrontal cortex. The formulation of our approach requires us to consider fundamental conceptual and methodological issues associated with consciousness. The most significant of these issues concerns the scientific use of introspective evidence. We outline and justify a conservative methodological approach to the use of introspective evidence, with attention to the difficulties historically associated with its use in psychology. (shrink)

O'Brien & Opie do not address the question of the psychotherapeutic role of unconscious representational states such as beliefs. A dilemma is proposed: if they accept the legitimacy of such states then they should modify what they say about dissociation, and if they do not, they owe us an account of why.

This book contains a representationalist theory of self-consciousness and of the phenomenal first-person perspective. It draws on empirical data from the cognitive and neurosciences.

When are psychologists entitled to call a certain theoretical construct "consciousness?" Over the past few decades cognitive psychologists have reintroduced almost the entire conceptual vocabulary of common sense psychology, but now in a way that is tied explicitly to reliable empirical observations, and to compelling and increasingly adequate theoretical models. Nevertheless, until the past few years most cognitive psychologists and neuroscientists avoided dealing with consciousness. Today there is an increasing willingness to do so. But is "consciousness" different from other theoretical (...) entities like "working memory" or "mental imagery"? Some argue that under no circumstances can empirical science speak of consciousness as such, while others claim that the scientific goal is "knowing what it is like to be a bat" --- to share an organism's conscious experience . The Bat Criterion is ominously reminiscent of the protracted debate on the consciousness of ants and amoebas that caused so much uneasiness in psychology around 1900. It seems to demand that we first solve the mind-body problem as a condition of doing sensible science, and thereby creates the risk of endless, fruitless controversy. The endless philosophical debate about consciousness helped trigger the Behaviorist revolution about 1913, which threw out the baby of consciousness with the bathwater of perennial, circular debate. We've been that way; let's not go back to it. This paper maintains that the position of behavioristic denial is far too restrictive, but that the Bat Criterion is far too demanding --- that in fact, we only need to specify comparable pairs of psychological phenomena that differ only in the fact that one member of any pair is conscious, while the other is not. This "method of contrastive analysis" is a generalization of the experimental method, with consciousness as a variable whose interaction with other psychological and biological phenomena can be assessed in standard ways. As usual in science, this strategy is pragmatic: If it appears to yield sensible results, it can be a stepping-stone toward further understanding . This paper describes five sets of well-established pairs of phenomena that meet these criteria. Others are presented elsewhere, with more of a theoretical interpretation . Here I simply want to show that any adequate theory of conscious experience must satisfy these demanding but achievable empirical constraints. (shrink)

The "relational mind" approach to the inner content of consciousness is developed in terms of various control structures and processing strategies and their possible neurobiological identifications in brain sites. This leads naturally to a division of consciousness into a passive and an active part. A global control structure for the "single strand" aspect of consciousness is proposed as the thalamo-nucleus reticularis thalami-cortex coupled system, which is related to experimental data on the electrical stimulation of awareness. Local control, in terms of (...) excitatory transfer from pre-processing sites to posterior working memory regions, is supported by data on subliminal perception timing and disambiguation of poorly defined percepts. The inner content of consciousness is understood as arising from the resulting relational features between inputs and stored pre-processing and episodic memories. Strong analogies are drawn between emergent properties of the model and suggested properties of "raw feels", supporting the thesis that working memories are the initial sites for the emergence of phenomenal awareness, and the frontal lobes for its further adumbration in terms of higher cognitive processing, including the creation of self. (shrink)

This article replies to the main objections raised by the commentators on Carruthers . It discusses the question of what evidence is relevant to the assessment of dispositional higher-order thought theory; it explains how the actual properties of phenomenal consciousness can be dispositionally constituted; it discusses the case of pains and other bodily sensations in non-human animals and young children; it sketches the case for preferring higher-order to first-order theories of phenomenal consciousness; and it replies to some miscellaneous points and (...) objections. (shrink)

The term consciousness is an important one in the vernacular of the western literature in many fields. It is no wonder that scientists have assumed that consciousness will be found as a component of the human brain and that we will come to understand its neural basis. However, there is rather little in common between consciouness as the neurologist would use it to diagnose the vegetative state, how the feminist would use it to support raising male consciousness of the economic (...) plight of women and as the philosopher would use it when defining the really hard question of the subjective state of awareness induced by sensory qualities. When faced with this kind of problem it is usual to subdivide the term into more manageable perhaps partly operational definitions. Three meanings that capture aspects of consciousness are: the neurology of the state of mind allowing coherent orientation to time and place the selection of sensory or memorial information for awareness and the voluntary control over overt responses. In each of these cases the mechanisms of consciousness overlap with attentional networks that have been explored with the methods of cognitive neuroscience. In this paper we explore the overlap and discuss how to exploit the growing knowledge of attentional networks to constrain ideas of consciousness. (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)

A substantial body of research has established that even when we are not consciously aware of the faces of others we are nevertheless sensitive to, and impacted by their facial expression. In this paper, we consider this body of research from a new perspective by examining the functions of unconscious perception revealed by these studies. A consideration of the literature from this perspective highlights that existing research methods are limited when it comes to revealing possible functions of unconscious perception. The (...) critical shortcoming is that in all of the methods, the perceived facial expression remains outside of awareness. This is a problem because there are good reasons to believe that one important function of unconsciously perceived negative faces is to attract attention so that they are consciously perceived; such conscious perception, however, is never allowed with existing methodologies. We discuss recent studies of emotional face perception under conditions of visual search that address this issue directly. Further, we suggest that methodologies that do not examine cognitive processes as they occur in more natural settings may result in fundamental misunderstandings of human cognition. (shrink)

How internal categories influence how we perceive the world is a fundamental question in cognitive sciences. Yet, the relation between perceptual awareness and perceptual categorization has remained largely uncovered so far. Here, we addressed this question by focusing on face perception during subliminal and conscious perception. We used morphed continua between two face identities and we assessed, through a masked priming paradigm, the perceptual processing of these morphed faces under subliminal and supraliminal conditions. We found that priming from subliminal faces (...) followed linearly the information present in the primes, while priming from visible faces revealed a non-linear profile, indicating a categorical processing of face identities. Our results thus point to a special relation between perceptual awareness and categorical processing of faces, and support the dissociation between two modes of information processing: a subliminal mode involving analog treatment of stimuli information, and a supraliminal mode relying on discrete representation. (shrink)