Much of the contemporary debate in the philosophy of mind is concerned with the clash between certain strongly held intuitions and what science tells us about the mind and its relation to the world. What science tells us about the mind points strongly towards some version or other of physicalism. The intuitions, in one way or another, suggest that there is something seriously incomplete about any purely physical story about the mind.

How is consciousness possible? What biological purpose does it serve? And why do we value it so highly? In Soul Dust, the psychologist Nicholas Humphrey, a leading figure in consciousness research, proposes a startling new theory. Consciousness, he argues, is nothing less than a magical-mystery show that we stage for ourselves inside our own heads. This self-made show lights up the world for us and makes us feel special and transcendent. Thus consciousness paves the way for spirituality, and allows us, (...) as human beings, to reap the rewards, and anxieties, of living in what Humphrey calls the "soul niche." Tightly argued, intellectually gripping, and a joy to read, Soul Dust provides answers to the deepest questions. It shows how the problem of consciousness merges with questions that obsess us all--how life should be lived and the fear of death. Resting firmly on neuroscience and evolutionary theory, and drawing a wealth of insights from philosophy and literature, Soul Dust is an uncompromising yet life-affirming work--one that never loses sight of the majesty and wonder of consciousness. (shrink)

The Three Papers comprising this series, together with my earlier [34] also published in this journal, constitute an attempt to set out the major issues in the theoretical domain of reduction and to develop a general theory of theory reduction. The fourth paper, [34], though published separately from this trio, is integral to the presentation and should be read in conjunction with these papers. Even so, the presentation is limited in scope – roughly, to intertheoretic reduction among empirical theories – (...) and informal in presentation – not least because a satisfying formal account of theories has yet to be offered. And despite the length, the treatment is still condensed; often corroborating and/or intuitively helpful detail has had to be consigned to footnotes or omitted. I approach the problem from within my own naturalistic realist philosophy of science and formal analysis of abstract hierarchy in theory. The sources for the former are [25], [29], [31], and [32] and those for the latter essentially [27] and [30]. Hierarchical notions played a significant role in the already published [34]. (shrink)

An exciting theory in neuroscience is that the brain is an organ for prediction error minimization. This theory is rapidly gaining influence and is set to dominate the science of mind and brain in the years to come. PEM has extreme explanatory ambition, and profound philosophical implications. Here, I assume the theory, briefly explain it, and then I argue that PEM implies that the brain is essentially self-evidencing. This means it is imperative to identify an evidentiary boundary between the brain (...) and its environment. This boundary defines the mind-world relation, opens the door to skepticism, and makes the mind transpire as more inferentially secluded and neurocentrically skull-bound than many would nowadays think. Therefore, PEM somewhat deflates contemporary hypotheses that cognition is extended, embodied and enactive; however, it can nevertheless accommodate the kinds of cases that fuel these hypotheses. (shrink)

It is often claimed that the greatest value of the Bayesian framework in cognitive science consists in its unifying power. Several Bayesian cognitive scientists assume that unification is obviously linked to explanatory power. But this link is not obvious, as unification in science is a heterogeneous notion, which may have little to do with explanation. While a crucial feature of most adequate explanations in cognitive science is that they reveal aspects of the causal mechanism that produces the phenomenon to be (...) explained, the kind of unification afforded by the Bayesian framework to cognitive science does not necessarily reveal aspects of a mechanism. Bayesian unification, nonetheless, can place fruitful constraints on causal–mechanical explanation. 1 Introduction2 What a Great Many Phenomena Bayesian Decision Theory Can Model3 The Case of Information Integration4 How Do Bayesian Models Unify?5 Bayesian Unification: What Constraints Are There on Mechanistic Explanation?5.1 Unification constrains mechanism discovery5.2 Unification constrains the identification of relevant mechanistic factors5.3 Unification constrains confirmation of competitive mechanistic models6 ConclusionAppendix. (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)

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.

Brains, it has recently been argued, are essentially prediction machines. They are bundles of cells that support perception and action by constantly attempting to match incoming sensory inputs with top-down expectations or predictions. This is achieved using a hierarchical generative model that aims to minimize prediction error within a bidirectional cascade of cortical processing. Such accounts offer a unifying model of perception and action, illuminate the functional role of attention, and may neatly capture the special contribution of cortical processing to (...) adaptive success. This target article critically examines this approach, concluding that it offers the best clue yet to the shape of a unified science of mind and action. Sections 1 and 2 lay out the key elements and implications of the approach. Section 3 explores a variety of pitfalls and challenges, spanning the evidential, the methodological, and the more properly conceptual. The paper ends (sections 4 and 5) by asking how such approaches might impact our more general vision of mind, experience, and agency. (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)

A central debate in the philosophy of perception concerns the range of properties that can be represented in perceptual experience. Are the contents of perceptual experience restricted to ‘low-level’ properties such as location, shape and texture, or can ‘high-level’ properties such as being a tomato, being a pine tree or being a watch also be represented in perceptual experience? This paper explores the bearing of gist perception on the admissible contents debate, arguing that it provides qualified support for the claim (...) that certain kinds of high-level properties—such as being a natural scene —can be perceptually represented. (shrink)

The attention schema theory offers one possible account for how we claim to have consciousness. The theory begins with attention, a mechanistic method of handling data in which some signals are enhanced at the expense of other signals and are more deeply processed. In the theory, the brain does more than just use attention. It also constructs an internal model, or representation, of attention. That internal model contains incomplete, schematic information about what attention is, what the consequences of attention are, (...) and what its own attention is doing at any moment. This 'attention schema' is used to help control attention, much like the 'body schema', the brain's internal simulation of the body, is used to help control the body. Subjective awareness -- consciousness -- is the caricature of attention depicted by that internal model. This article summarizes the theory and discusses its relationship to the approach to consciousness that is called 'illusionism'. (shrink)

This article presents the case for an approach to consciousness that I call illusionism. This is the view that phenomenal consciousness, as usually conceived, is illusory. According to illusionists, our sense that it is like something to undergo conscious experiences is due to the fact that we systematically misrepresent them as having phenomenal properties. Thus, the task for a theory of consciousness is to explain our illusory representations of phenomenality, not phenomenality itself, and the hard problem is replaced by the (...) illusion problem. Although it has had powerful defenders, illusionism remains a minority position, and it is often dismissed as failing to take consciousness seriously. This article seeks to rebut this accusation. It defines the illusionist programme, outlines its attractions, and defends it against some common objections. It concludes that illusionism is a coherent and attractive approach, which deserves serious consideration. (shrink)

The goal of this short chapter, aimed at philosophers, is to provide an overview and brief explanation of some central concepts involved in predictive processing (PP). Even those who consider themselves experts on the topic may find it helpful to see how the central terms are used in this collection. To keep things simple, we will first informally define a set of features important to predictive processing, supplemented by some short explanations and an alphabetic glossary. -/- The features described here (...) are not shared in all PP accounts. Some may not be necessary for an individual model; others may be contested. Indeed, not even all authors of this collection will accept all of them. To make this transparent, we have encouraged contributors to indicate briefly which of the features are necessary to support the arguments they provide, and which (if any) are incompatible with their account. For the sake of clarity, we provide the complete list here, very roughly ordered by how central we take them to be for “Vanilla PP” (i.e., a formulation of predictive processing that will probably be accepted by most researchers working on this topic). More detailed explanations will be given below. Note that these features do not specify individually necessary and jointly sufficient conditions for the application of the concept of “predictive processing”. All we currently have is a semantic cluster, with perhaps some overlapping sets of jointly sufficient criteria. The framework is still developing, and it is difficult, maybe impossible, to provide theory-neutral explanations of all PP ideas without already introducing strong background assumptions. (shrink)

How can phenomenal consciousness exist as an integral part of a physical universe? How can the technicolour phenomenology of our inner lives be created out of the complex neural activities of our brains? Many have despaired of finding answers to these questions; and many have claimed that human consciousness is inherently mysterious. Peter Carruthers argues, on the contrary, that the subjective feel of our experience is fully explicable in naturalistic terms. Drawing on a variety of interdisciplinary resources, he develops and (...) defends a novel account in terms of higher-order thought. He shows that this can explain away some of the more extravagant claims made about phenomenal consciousness, while substantively explaining the key subjectivity of our experience. Written with characteristic clarity and directness, and surveying a wide range of extant theories, this book is essential reading for all those within philosophy and psychology interested in the problem of consciousness. (shrink)

How is it that thoroughly physical material beings such as ourselves can think, dream, feel, create and understand ideas, theories and concepts? How does mere matter give rise to all these non-material mental states, including consciousness itself? An answer to this central question of our existence is emerging at the busy intersection of neuroscience, psychology, artificial intelligence, and robotics.In this groundbreaking work, philosopher and cognitive scientist Andy Clark explores exciting new theories from these fields that reveal minds like ours to (...) be prediction machines - devices that have evolved to anticipate the incoming streams of sensory stimulation before they arrive. These predictions then initiate actions that structure our worlds and alter the very things we need to engage and predict. Clark takes us on a journey in discovering the circular causal flows and the self-structuring of the environment that define "the predictive brain." What emerges is a bold, new, cutting-edge vision that reveals the brain as our driving force in the daily surf through the waves of sensory stimulation. (shrink)

A new theory is taking hold in neuroscience. It is the theory that the brain is essentially a hypothesis-testing mechanism, one that attempts to minimise the error of its predictions about the sensory input it receives from the world. It is an attractive theory because powerful theoretical arguments support it, and yet it is at heart stunningly simple. Jakob Hohwy explains and explores this theory from the perspective of cognitive science and philosophy. The key argument throughout The Predictive Mind is (...) that the mechanism explains the rich, deep, and multifaceted character of our conscious perception. It also gives a unified account of how perception is sculpted by attention, and how it depends on action. The mind is revealed as having a fragile and indirect relation to the world. Though we are deeply in tune with the world we are also strangely distanced from it. (shrink)

My thesis is: introspection is not a single process but a plurality of processes. It’s a plurality both within and between cases: most individual introspective judgments arise from a plurality ofprocesses (that’s the Within-case claim), and the collection of processes issuing in introspective judgments differs from case to case (that’s the between-case claim). Introspection is not the operation of a single cognitive mech- anism or small collection ofmechanisms. Introspective judgments arise from a shift- ing confluence ofmany processes, recruited opportunistically.

In this book, Derk Pereboom explores how physicalism might best be formulated and defended against the best anti-physicalist arguments. Two responses to the knowledge and conceivability arguments are set out and developed. The first exploits the open possibility that introspective representations fail to represent mental properties as they are in themselves; specifically, that introspection represents phenomenal properties as having certain characteristic qualitative natures, which these properties might actually lack. The second response draws on the proposal that currently unknown fundamental intrinsic (...) properties provide categorical bases for known physical properties and would also yield an account of consciousness. While there are non-physicalist versions of this position, some are amenable to physicalism. The book's third theme is a defense of a nonreductive account of physicalism. The type of nonreductivism endorsed departs from others in that it rejects all token identity claims for psychological and microphysical entities. The deepest relation between the mental and the microphysical is constitution, where this relation is not to be explicated by the notion of identity. (shrink)

Philosophers tend to be pretty impressed by human self-knowledge. Descartes (1641/1984) thought our knowledge of our own stream of experience was the secure and indubitable foundation upon which to build our knowledge of the rest of the world. Hume – who was capable of being skeptical about almost anything – said that the only existences we can be certain of are our own sensory and imagistic experiences (1739/1978, p. 212). Perhaps the most prominent writer on self-knowledge in contemporary philosophy is (...) Sydney Shoemaker. The central aim of much of his work has been to show that certain sorts of error are impossible (1963, 1988, 1994). David Chalmers has likewise attempted to show that, for a suitably constrained class of beliefs about one’s own consciousness, error is impossible (2003, sec. 4.1). Even philosophers most of the community thinks of as pessimistic about self-knowledge of consciousness seem to me, really, to be fairly optimistic. Paul Churchland, famous for his disdain of ordinary people’s knowledge about the mind, compares the accuracy of introspection to the accuracy of sense perception – pretty good, presumably, about medium-sized, nearby matters (1985, 1988). Dan Dennett, often cited as a pessimist about introspective report, actually says that we can come close to infallibility when charitably interpreted (2002). The above references concern knowledge of the stream of conscious experience, but philosophers have also tended to be impressed with our self-knowledge of our attitudes, such as our beliefs and desires. Consider this: Although I can be wrong about its being sunny outside, I can’t in the same way be wrong, it seems, about the fact that I think it’s sunny outside. Some.. (shrink)

I argue that when perception plays a guiding role in intentional bodily action, it is a necessary part of that action. The argument begins with a challenge that necessarily arises for embodied agents, what I call the Many-Many Problem. The Problem is named after its most common case where agents face too many perceptual inputs and too many possible behavioral outputs. Action requires a solution to the Many-Many Problem by selection of a specific linkage between input and output. In bodily (...) action the agent perceptually selects, and in this way perceptually attends to, relevant information so as to guide the execution of specific movements. Since perceptual attention is a necessary part of solving the Many-Many Problem, it is a necessary part of bodily action. Indeed, the process of implementing a solution to the Many-Many Problem, as constrained by the agent's motivational state, just is the agent's performing an intentional bodily action in the relevant way. (shrink)

Phenomenology is the study of structures of consciousness as experienced from the first-person point of view. The central structure of an experience is its intentionality, its being directed toward something, as it is an experience of or about some object. An experience is directed toward an object by virtue of its content or meaning (which represents the object) together with appropriate enabling conditions.

In Rahul Banerjee and Bikas K. Chakrabarti (eds.), Progress in Brain Research, 168: 215-246. Amsterdam: Elsevier. Electronic offprint available upon request.

In recent years there has been an explosion of scientific work on consciousness in cognitive neuroscience, psychology, and other fields. It has become possible to think that we are moving toward a genuine scientific understanding of conscious experience. But what is the science of consciousness all about, and what form should such a science take? This chapter gives an overview of the agenda.

Abstract. A rhesus monkey, Helen, from whom the striate cortex was almost totally removed, was studied intensively over a period of 8 years. During this time she regained an effective, though limited, degree of visually guided behaviour. The evidence suggests that while Helen suffered a permanent loss of `focal vision she retained (initially unexpressed) the capacity for `ambient vision.

" 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)

A representationalist analysis of strong first-person phenomena is developed (Baker 1998), and it is argued that conscious, cognitive self-reference can be naturalized under this representationalist analysis. According to this view, the phenomenal first-person perspective is a condition of possibility for the emergence of a cognitive first-person perspective. Cognitive self-reference always is reference to the phenomenal content of a transparent self-model. The concepts of phenomenal transparency and introspection are clarified. More generally, I suggest that the concepts of phenomenal opacity and phenomenal (...) transparency are interesting instruments for analyzing conscious, self-representational content, and that their relevance in understanding reflexive, i.e., cognitive subjectivity may have been overlooked in the past. (shrink)

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

The idea of representation has been central in discussions of intentionality for many years. But only more recently has it begun playing a wider role in the philosophy of mind, particularly in theories of consciousness. Indeed, there are now multiple representational theories of consciousness, corresponding to different uses of the term "conscious," each attempting to explain the corresponding phenomenon in terms of representation. More cautiously, each theory attempts to explain its target phenomenon in terms of _intentionality_, and assumes that intentionality (...) is representation. (shrink)

This chapter analyzes aspects of the relationship between consciousness and intentionality. It focuses on the phenomenal character and the intentional content of perceptual states, canvassing various possible relations among them. It argues that there is a good case for a sort of representationalism, although this may not take the form that its advocates often suggest. By mapping out some of the landscape, the chapter tries to open up territory for different and promising forms of representationalism to be explored in the (...) future. In particular, it argues for a nonreductive, narrow, and Fregean variety of representationalism, which contrasts strongly with more widely explored varieties. It concludes with some words about the fundamental relationship between consciousness and intentionality. (shrink)

The book is an extended study of the problem of consciousness. After setting up the problem, I argue that reductive explanation of consciousness is impossible , and that if one takes consciousness seriously, one has to go beyond a strict materialist framework. In the second half of the book, I move toward a positive theory of consciousness with fundamental laws linking the physical and the experiential in a systematic way. Finally, I use the ideas and arguments developed earlier to defend (...) a form of strong artificial intelligence and to analyze some problems in the foundations of quantum mechanics. (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)

This paper considers the Cartesian theatre as a metaphor for the virtual reality models that the brain uses to make inferences about the world. This treatment derives from our attempts to understand dreaming and waking consciousness in terms of free energy minimization. The idea here is that the Cartesian theatre is not observed by an internal audience but furnishes a theatre in which fictive narratives and fantasies can be rehearsed and tested against sensory evidence. We suppose the brain is driven (...) by the imperative to infer the causes of its sensory samples; in much the same way as scientists are compelled to test hypotheses about experimental data. This recapitulates Helmholtz's notion of unconscious inference and Gregory's treatment of perception as hypothesis testing. However, we take this further and consider the active sampling of the world as the gathering of confirmatory evidence for hypotheses based on our virtual reality. The ensuing picture of consciousness resolves a number of seemingly hard problems in consciousness research and is internally consistent with current thinking in systems neuroscience and theoretical neurobiology. In this formalism, there is a dualism that distinguishes between the process of inference and the process that entails inference. This separation is reflected by the distinction between beliefs and the physical brain states that encode them. This formal approach allows us to appeal to simple but fundamental theorems in information theory and statistical thermodynamics that dissolve some of the mysterious aspects of consciousness. (shrink)

Ever since its discovery nearly thirty years ago, the phenomenon of blindsight — vision without visual consciousness — has been the source of great controversy in the philosophy of mind, psychology, and the neurosciences. Despite the fact that blindsight is widely acknowledged to be a critical test-case for theories of mind, Blindsight and the Nature of Consciousness is the first extended treatment of the phenomenon from a philosophical perspective. Holt argues, against much received wisdom, for a thorough-going materialism — the (...) view not only that mental states are brain states, but (much more controversially) that mental properties are physical as well. Designed not only for philosophers and scientists, Blindsight and the Nature of Consciousness has something to say to anyone interested in the mystery of the human mind and in how philosophers and scientists are working toward solving that mystery. (shrink)