Subjectivity is essential to consciousness. But though subjectivity is necessary for consciousness it is not sufficient. In part one I derive a distinction between conscious awareness and unconscious subjectivity from a critique of Block’s (1995) distinction between access and phenomenal consciousness. In part two I contrast two historically influential models of unconscious thought: cognitive and psychoanalytic. The widely held cognitive model does not cover, as it should, the class of "for me" mental states that remain unconscious. In particular, personalist approaches (...) to emotion require a theory of unconscious subjectivity to handle the case of unconscious emotion. (shrink)

Rationalizing the perceptual effects of spectral stimuli has been a major challenge in vision science for at least the last 200 years. Here we review evidence that this otherwise puzzling body of phenomenology is generated by an empirical strategy of perception in which the color an observer sees is entirely determined by the probability distribution of the possible sources of the stimulus. The rationale for this strategy in color vision, as in other visual perceptual domains, is the inherent ambiguity of (...) the real-world origins of any spectral stimulus. (shrink)

A broad range of evidence regarding the functional organization of the vertebrate brain – spanning from comparative neurology to experimental psychology and neurophysiology to clinical data – is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form (...) a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain – culminating in the cerebral cortex of mammals – came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. (Published Online May 1 2007) Key Words: action selection; anencephaly; central decision making; consciousness; control architectures; hydranencephaly; macrosystems; motivation; target selection; zona incerta. (shrink)

Several authors within psychology, neuroscience and philosophy take for granted that standard empirical research techniques are applicable when studying consciousness. In this article, it is discussed whether one of the key methods in cognitive neuroscience – the contrastive analysis – suffers from any serious confounding when applied to the field of consciousness studies; that is to say, if there are any systematic difficulties when studying consciousness with this method that make the results untrustworthy. Through an analysis of theoretical arguments in (...) favour of using contrastive analysis, combined with analyses of empirical findings, I conclude by arguing for three factors that currently are confounding of research using contrastive analysis. These are (1) unconscious processes, (2) introspective reports, and (3) attention. (shrink)

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)

Subliminal perception (SP) is today considered a well-supported theory stating that perception can occur without conscious awareness and have a significant impact on later behaviour and thought. In this article, we first present and discuss different approaches to the study of SP. In doing this, we claim that most approaches are based on a dichotomic measure of awareness. Drawing upon recent advances and discussions in the study of introspection and phenomenological psychology, we argue for both the possibility and necessity of (...) using an elaborated measure of subjective states. In the second part of the article, we present findings where these considerations are implemented in an empirical study. The results and implications are discussed in detail, both with reference to SP, and in relation to the more general problem of using elaborate introspective reports as data in relation to studies of cognition. (shrink)

The standard behavioral index for human consciousness is the ability to report events with accuracy. While this method is routinely used for scientific and medical applications in humans, it is not easy to generalize to other species. Brain evidence may lend itself more easily to comparative testing. Human consciousness involves widespread, relatively fast low-amplitude interactions in the thalamocortical core of the brain, driven by current tasks and conditions. These features have also been found in other mammals, which suggests that consciousness (...) is a major biological adaptation in mammals. We suggest more than a dozen additional properties of human consciousness that may be used to test comparative predictions. Such homologies are necessarily more remote in non-mammals, which do not share the thalamocortical complex. However, as we learn more we may be able to make “deeper” predictions that apply to some birds, reptiles, large-brained invertebrates, and perhaps other species. (shrink)

Carruthers, P. . Natural theories of consciousness. European Journal of Philosophy.

In humans, conscious perception and cognition depends upon the thalamocortical complex, which supports perception, explicit cognition, memory, language, planning, and strategic control. When parts of the T-C system are damaged or stimulated, corresponding effects are found on conscious contents and state, as assessed by reliable reports. In contrast, large regions like cerebellum and basal ganglia can be damaged without affecting conscious cognition directly. Functional brain recordings also show robust activity differences in cortex between experimentally matched conscious and unconscious events. This (...) basic anatomy and physiology is highly conserved in mammals and perhaps ancestral reptiles. While language is absent in other species, homologies in perception, memory, and motor cortex suggest that consciousness of one kind or another may be biologically fundamental and phylogenetically ancient. In humans we infer subjective experiences from behavioral and brain evidence. This evidence is quite similar in other mammals and perhaps some non-mammalian species. On the weight of the biological evidence, therefore, subjectivity may be conserved in species with human-like brains and behavior. (shrink)

In a recent article, [Sergent, C. & Dehaene, S. . Is consciousness a gradual phenomenon? Evidence for an all-or-none bifurcation during the attentional blink, Psychological Science, 15, 720–729] claim to give experimental support to the thesis that there is a clear transition between conscious and unconscious perception. This idea is opposed to theoretical arguments that we should think of conscious perception as a continuum of clarity, with e.g., fringe conscious states [Mangan, B. . Sensation’s ghost—the non-sensory “fringe” of consciousness, Psyche, (...) 7, 18]. In the experimental study described in this article, we find support for this opposite notion that we should have a parsimonious account of conscious perception. Our reported finding relates to the hypothesis that there is more than one perceptual threshold [Merikle, P.M., Smilek, D. & Eastwood, J.D. . Perception without awareness: perspectives from cognitive psychology, Cognition, 79, 115–134], but goes further to argue that there are different “levels” of conscious perception. (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)

Quite a few recent models are rapidly introducing new concepts describing different levels of consciousness. This situation is getting confusing because some theorists formulate their models without making reference to existing views, redundantly adding complexity to an already difficult problem. In this paper, I present and compare nine neurocognitive models to highlight points of convergence and divergence. Two aspects of consciousness seem especially important: perception of self in time and complexity of self-representations. To this I add frequency of self-focus, amount (...) of self-related information, and accuracy of self-knowledge. Overall, I conclude that many novel concepts (e.g., reflective, primary, core, extended, recursive, and minimal consciousness) are useful in helping us distinguish between delicate variations in consciousness and in clarifying theoretical issues that have been intensely debated in the scientific literature—e.g., consciousness in relation to mirror self-recognition and language. Ó 2005 Elsevier Inc. All rights reserved. (shrink)

Voluntary acts are preceded by electrophysiological (RPs). With spontaneous acts involving no preplanning, the main negative RP shift begins at about200 ms. Control experiments, in which a skin stimulus was timed (S), helped evaluate each subject's error in reporting the clock times for awareness of any perceived event.

This book brings together an international group of neuroscientists and philosophers who are investigating how the content of subjective experience is...

conscious content like ``the self in the act of In 1989 the philosopher Colin McGinn asked the knowing'' (see, e.g., chapters 7 and 20 in this following question: ``How can technicolor phe- volume) or high-level phenomenal properties like nomenology arise from soggy gray matter?'' ``coherence'' or ``holism'' (e.g., chapters 8 and 9 (1989: 349). Since then many authors in the ®eld in this volume). But what, precisely, does it mean of consciousness research have quoted this ques- that conscious experience has (...) a ``content''? Is tion over and over, like a slogan that in a nut- this an entity open to empirical research pro- shell conveys a deep and important theoretical grams and interdisciplinary cooperation? And problem. It seems that almost none of them dis- what would it mean to map this content onto covered the subtle trap inherent in this question. physical states ``under a certain description''? In The brain is not gray. The brain is colorless. other words: What kinds of relations a. (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)

This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do.The basic assumption is that vision depends on the eye which is connected to the brain. The (...) author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision—and what this book is about. (shrink)

In treating cognition as problem solving, Andy Clark suggests, we may often abstract too far from the very body and world in which our brains evolved to guide...

In the past decade, the notion of a neural correlate of consciousness (or NCC) has become a focal point for scientific research on consciousness (Metzinger, 2000a). A growing number of investigators believe that the first step toward a science of consciousness is to discover the neural correlates of consciousness. Indeed, Francis Crick has gone so far as to proclaim that ‘we … need to discover the neural correlates of consciousness.… For this task the primate visual system seems especially attractive.… No (...) longer need one spend time attempting … to endure the tedium of philosophers perpetually disagreeing with each other. Con- sciousness is now largely a scientific problem’ (Crick, 1996, p. 486).2 Yet the question of what it means to be a neural correlate of consciousness is actually far from straightforward, for it involves fundamental empirical, methodological, and _philosophical _issues about the nature of consciousness and its relationship to the brain. Even if one assumes, as we do, that states of consciousness causally depend on states of the brain, one can nevertheless wonder in what sense there is, or could be, such a thing as a neural correlate of consciousness. (shrink)

In this collection of essays we hear from an international array of computer and brain scientists who are actively working from both the machine and human ends...

Commentary on John Searle's Article John Searle presents a philosopher's view of how conscious experience and free action relate to brain function. That view demands an examination by a neuroscientist who has experimentally investigated this issue.

The Embodied Mind provides a unique, sophisticated treatment of the spontaneous and reflective dimension of human experience.

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)

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)

A traditional view of perception and action makestwo assumptions: that the causal flow betweenperception and action is primarily linear or one-way,and that they are merely instrumentally related toeach other, so that each is a means to the other.Either or both of these assumptions can be rejected. Behaviorism rejects the instrumental but not theone-way aspect of the traditional view, thus leavingitself open to charges of verificationism. Ecologicalviews reject the one-way aspect but not theinstrumental aspect of the traditional view, so thatperception and (...) action are seen as instrumentallyinterdependent. It is argued here that a betteralternative is to reject both assumptions, resultingin a two-level interdependence view in whichperception and action co-depend on dynamicallycircular subpersonal relations and as a result may bemore than merely instrumentally interdependent. Thisis illustrated by reference to motor theories ofperception and control theories of action. (shrink)

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

" 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)

" Qualia " is an unfamiliar term for something that could not be more familiar to each of us: the ways things seem to us. As is so often the case with philosophical jargon, it is easier to give examples than to give a definition of the term. Look at a glass of milk at sunset; the way it looks to you--the particular, personal, subjective visual quality of the glass of milk is the quale of your visual experience at the (...) moment. The way the milk tastes to you then is another, gustatory quale, and how it sounds to you as you swallow is an auditory quale; These various "properties of conscious experience" are prime examples of qualia. Nothing, it seems, could you know more intimately than your own qualia ; let the entire universe be some vast illusion, some mere figment of Descartes' evil demon, and yet what the figment is made of will be the qualia of your hallucinatory experiences. Descartes claimed to doubt everything that could be doubted, but he never doubted that his conscious experiences had qualia, the properties by which he knew or apprehended them. (shrink)

The mind-body problem in contemporary philosophy has two parts: the problem of mental causation and the problem of consciousness. These two parts are not unrelated; in fact, it can be helpful to see them as two horns of a dilemma. On the one hand, the causal interaction between mental and physical phenomena seems to require that all causally efficacious mental phenomena are physical; but on the other hand, the phenomenon of consciousness seems to entail that not all mental phenomena are (...) physical.2 One may avoid this dilemma by adopting an epiphenomenalist view of consciousness, of course; but there is little independent reason for believing such a view. Rejecting epiphenomenalism, then, leaves contemporary philosophers with their problem: mental causation inclines them towards physicalism, while consciousness inclines them towards dualism. (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)

Searle suggests biological naturalism as a solution to the mind-brain problem that escapes traditional terminology with its seductive pull towards either dualism or materialism. We reconstruct Searle's argument and demonstrate that it needs additional support to represent a position truly located between dualism and materialism. The aim of our paper is to provide such an additional argument. We introduce the concept of "autoepistemic limitation" that describes our principal inability to directly experience our own brain as a brain from the first-person (...) perspective. The neglect of the autoepistemic limitation leads to inferences from epistemic properties to ontological features - we call this "epistemic-ontological inference." Searle attempts to avoid such epistemic-ontological inference but does not provide a sufficient argument. Once the autoepistemic limitation is considered, epistemic-ontological inference can be avoided. As a consequence, one can escape traditional terminology with its seductive pull towards either dualism or materialism. (shrink)

The title of The Rediscovery of the Mind suggests the question "When was the mind lost?" Since most people may not be aware that it ever was lost, we must also then ask "Who lost it?" It was lost, of course, only by philosophers, by certain philosophers. This passed unnoticed by society at large. The "rediscovery" is also likely to pass unnoticed. But has the mind been rediscovered by the same philosophers who "lost" it? Probably not. John Searle is an (...) analytic philosopher, with some of the same notions as the positivists and behaviorists who rejected consciousness and "lost" the mind in the first place, but he also does not sound like the kind of reductionist who would have joined that crowd. His views, indeed, are sensible enough, and some of his insights so important, that it is a shame to find his thought profoundly limited by some of the same mistakes and prejudices that ruined philosophy, and not just philosophy of mind, under the influence of those positivists and behaviorists. There is enough of genuine value in his treatment, that it can easily be taken up and, with relatively slight modification, added to what is of permanent value in the history of philosophy. (shrink)

Everyone agrees that consciousness is a very special phenomenon, unique in several ways, but there is scant agreement on just how special it is, and whether or not an explanation of it can be accommodated within normal science. John Searle's view, defended with passion in this book, is highly idiosyncratic: what is special about consciousness is its "subjective ontology," but normal science can accommodate subjective ontology alongside (not within) its otherwise objective ontology. Once we clear away some widespread confusions about (...) what science requires, and dismiss the misbegotten field of cognitive science that has been engendered by those confusions, the subjective ontology of the mind, he claims, will lose its aura of unacceptable mystery. (shrink)

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

One of the promising approaches to the problem of consciousness has been the Higher-Order Monitoring Theory of Consciousness. According to the Higher-Order Monitoring Theory, a mental state M of a subject S is conscious iff S has another mental state, M*, such that M* is an appropriate representation of M. Recently, several philosophers have developed a Higher-Order Monitoring theory with a twist. The twist is that M and M* are construed as entertaining some kind of constitutive relation, rather than being (...) logically independent of each other. We may call this the Same-Order Monitoring Theory of Consciousness. In this paper, I discuss the nature of the Same-Order Monitoring Theory and argue for its superiority over the more traditional Higher-Order Monitoring Theory. (shrink)

No mental phenomenon is more central than consciousness to an adequate understanding of the mind. Nor does any mental phenomenon seem more stubbornly to resist theoretical treatment. Consciousness is so basic to the way we think about the mind that it can be tempting to suppose that no mental states exist that are not conscious states. Indeed, it may even seem mysterious what sort of thing a mental state might be if it is not a conscious state. On this way (...) of looking at things, if any mental states do lack consciousness, they are exceptional cases that call for special explanation or qualification. Perhaps dispositional or cognitive states exist that are not conscious, but nonetheless count as mental states. (shrink)

Carruthers' case against animal consciousness employs deeply flawed reasoning and is contradicted by both empirical and introspective evidence. Although in principle we cannot objectively establish for certain that anyone -- human or otherwise -- is phenomenally conscious, results of animal research on consciousness-changing drugs are uninterpretable unless one assumes that non-human animals have discriminable subjective states. Carruthers tries to argue that higher-order thoughts are the basis of subjective experiences, but the former are derived from the latter, not the other way (...) around. The position that only humans are conscious is reminiscent of other anthropocentric errors including outmoded notions of an Earth-centered universe created solely for humans. (shrink)