In visual science the term filling-inis used in different ways, which often leads to confusion. This target article presents a taxonomy of perceptual completion phenomena to organize and clarify theoretical and empirical discussion. Examples of boundary completion (illusory contours) and featural completion (color, brightness, motion, texture, and depth) are examined, and single-cell studies relevant to filling-in are reviewed and assessed. Filling-in issues must be understood in relation to theoretical issues about neuralignoring an absencejumping to a conclusionanalytic isomorphismCartesian materialism, a particular (...) neural stage that forms the immediate substrate of perceptual experience enactiveanimatesubpersonal” considerations about internal processing, but rather by considerations about the task of vision at the level of the animal or person interacting with the world. (shrink)

[opening paragraph] -- Clark: The `astonishing hypothesis' which you put forward in your book, and which you obviously feel is very controversial, is that `You, your joys and sorrows, your memories and ambitions, your sense of personal identity and free will are, in fact, no more than the behaviour of a vast assembly of nerve cells. As Lewis Carroll's Alice might have phrased it: `You're nothing but a pack of neurons'.' But it seems to me that this is not so (...) astonishing a statement for a scientist to make. Isn't this what reductionist science has always believed? (shrink)

Since its publication fifty years ago, this work has established itself as a classic. It casts the visual process in psychological terms and describes the creative way one's eye organizes visual material according to specific psychological premises. In 1974 this book was revised and expanded, and since then it has continued to burnish Rudolf Arnheim's reputation as a groundbreaking theoretician in the fields of art and psychology.

The mathematical theory of communication.

It has long been one of the most fundamental problems of philosophy, and it is now, John Searle writes, "the most important problem in the biological sciences": What is consciousness? Is my inner awareness of myself something separate from my body? In what began as a series of essays in The New York Review of Books, John Searle evaluates the positions on consciousness of such well-known scientists and philosophers as Francis Crick, Gerald Edelman, Roger Penrose, Daniel Dennett, David Chalmers, and (...) Israel Rosenfield. He challenges claims that the mind works like a computer, and that brain functions can be reproduced by computer programs. With a sharp eye for confusion and contradiction, he points out which avenues of current research are most likely to come up with a biological examination of how conscious states are caused by the brain. Only when we understand how the brain works will we solve the mystery of consciousness, and only then will we begin to understand issues ranging from artificial intelligence to our very nature as human beings. (shrink)

Latimer & Stevens (1997) develop a useful framework for discussing issues surrounding the definition and explanation of perceptual gestalts. They use this framework to raise some doubts about the possibility of “holistic” perceptual processing. However, I suspect that these doubts ultimately stem from assumptions about the nature of representation and processing in the brain, rather than from an analysis of part/whole concepts. I attempt to spell out these assumptions, and sketch an alternative perspective (deriving from Gestalt theory) that has the (...) potential to make sense of holism in perception. (shrink)

A scientific community cannot practice its trade without some set of received beliefs. These beliefs form the foundation of the "educational initiation that prepares and licenses the student for professional practice". The nature of the "rigorous and rigid" preparation helps ensure that the received beliefs are firmly fixed in the student's mind. Scientists take great pains to defend the assumption that scientists know what the world is like...To this end, "normal science" will often suppress novelties which undermine its foundations. Research (...) is therefore not about discovering the unknown, but rather "a strenuous and devoted attempt to force nature into the conceptual boxes supplied by professional education". (shrink)

Reveals the way the human eye acts on the visual world not just to represent but to actively construct the things we see, outlining the rules of vision and their application in art and technology. Reprint.

This comprehensively updated and expanded revision of the successful second edition continues to provide detailed coverage of the ever-growing range of research topics in vision. In Part I, the treatment of visual physiology has been extensively revised with an updated account of retinal processing, a new section explaining the principles of spatial and temporal filtering which underlie discussions in later chapters, and an up-to-date account of the primate visual pathway. Part II contains four largely new chapters which cover recent psychophysical (...) evidence and computational model of early vision: edge detection, perceptual grouping, depth perception, and motion perception. The models discussed are extensively integrated with physiological evidence. All other chapters in Parts II, III, and IV have also been thoroughly updated. (shrink)

Thomas S. Kuhn's classic book is now available with a new index.

It is fruitful to think of the representational and the organism-centered approaches as complementary levels of analysis, rather than mutually exclusive alternatives. Claims to the contrary by proponents of the organism-centered approach face what we call the “basketball problem.”.

In this paper I develop the thesis that dreams are essential to an understanding of waking consciousness. In the first part I argue in opposition to the philosophers Malcolm and Dennett that empirical evidence now shows dreams to be real conscious experiences. In the second part, three questions concerning consciousness research are addressed. (1) How do we isolate the system to be explained (consciousness) from other systems? (2) How do we describe the system thus isolated? (3) How do we reveal (...) the mechanisms on which this system is based? I suggest that empirical dream research combined with other empirical approaches can help us to sketch answers to all of these questions. I argue that the subjective form of dreams reveals the subjective, macro-level form of consciousness in general and that both dreams and the everyday phenomenal world may be thought of as constructed “virtual realities”. A major task for empirical consciousness research is to find out the mechanisms which bind this experienced world into a coherent whole. (shrink)

[opening paragraph] -- Clark: The `astonishing hypothesis' which you put forward in your book, and which you obviously feel is very controversial, is that `You, your joys and sorrows, your memories and ambitions, your sense of personal identity and free will are, in fact, no more than the behaviour of a vast assembly of nerve cells. As Lewis Carroll's Alice might have phrased it: `You're nothing but a pack of neurons'.' But it seems to me that this is not so (...) astonishing a statement for a scientist to make. Isn't this what reductionist science has always believed? (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)

What psychological and philosophical significance should we attach to recent efforts at computer simulations of human cognitive capacities? In answering this question, I find it useful to distinguish what I will call "strong" AI from "weak" or "cautious" AI. According to weak AI, the principal value of the computer in the study of the mind is that it gives us a very powerful tool. For example, it enables us to formulate and test hypotheses in a more rigorous and precise fashion. (...) But according to strong AI, the computer is not merely a tool in the study of the mind; rather, the appropriately programmed computer really is a mind, in the sense that computers given the right programs can be literally said to. (shrink)

The Mind-Body Problem Questions: What is the mind? What is its connection to the body? Most basic division of answers: Dualist and Materialist (or Physicalist) responses.

The book also introduces a host of new experimental techniques and major hypotheses to guide future research.

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

To make progress on the problem of consciousness, we have to confront it directly. In this paper, I first isolate the truly hard part of the problem, separating it from more tractable parts and giving an account of why it is so difficult to explain. I critique some recent work that uses reductive methods to address consciousness, and argue that such methods inevitably fail to come to grips with the hardest part of the problem. Once this failure is recognized, the (...) door to further progress is opened. In the second half of the paper, I argue that if we move to a new kind of nonreductive explanation, a naturalistic account of consciousness can be given. I put forward my own candidate for such an account: a nonreductive theory based on principles of structural coherence and organizational invariance, and a double-aspect theory of information. (shrink)

Many philosophers doubt that one can provide any successful explanation of sensory qualities - of how things look, feel, or seem to a perceiving subject. To provide such an explanation, one would need to explain qualitative facts in non-qualitative terms. Attempts to construct such explanations have seemed, in principle, doomed. Austen Clark examines the strategy used in psychophysics, psychometrics, and sensory neurophysiology to explain qualitative facts. He argues that this strategy could succeed: its structure is sound, and it can answer (...) the various philosophical objections lodged against it. On this basis Professor Clark presents an analysis of senosry qualities that offers the possibility of explaining at least some qualia, and he sketches how this scheme might eventually reduce to neurophysiology. If he is correct, we are not doomed to an eternity of mere acquaintance with our qualia. (shrink)

Pessoa et al. fail to make a clear distinction between visual perception and subjective visual awareness. Their most controversial claims, however, concern subjective visual awareness rather than visual perception: visual awareness is externalized to the “personal level,” thus denying the view that consciousness is a natural biological phenomenon somehow constructed inside the brain.

_One summary of the great Kant's view, to the extent that it can be summed up, is_ _that he takes determinism to be a kind of fact, and indeterminism to be another kind_ _of fact, and our freedom to be a fact too -- but takes this situation to have nothing to_ _do with the kind of compatibility of determinism and freedom proclaimed by such_ _Compatibilists as Hobbes and Hume. Thus Kant does not make freedom consistent_ _with determinism by taking (...) up a definition of freedom as voluntariness -- at bottom,_ _being able to do what you want. This he dismisses as a wretched subterfuge,_ _quibbling about words. Rather, the freedom he seeks to make consistent with_ _determinism does indeed seem to be the freedom of the Incompatibilists --_ _origination. Is he then an Incompatibilist? Well, against that, it can be said he does_ _not allow the existence of origination in what can be called the world we know, as_ _Incompatibilists certainly do._. (shrink)

Drawing on work in psychophysics, psychometrics, and sensory neurophysiology, Clark analyzes the character and defends the integrity of psychophysical explanations of qualitative facts, arguing that the structure of such explanations is sound and potentially successful.

It is argued that there is a role for the representational conception of vision, and that this is compatible with the task-level account advocated by Pessoa et al. However, the role of representations must be understood independently of our conscious experience of vision.

Dualist and Reductionist theories of mind disagree about whether or not consciousness can be reduced to a state of or function of the brain. They assume, however, that the contents of consciousness are separate from the external physical world as-perceived. According to the present paper this assumption has no foundation either in everyday experience or in science. Drawing on evidence for perceptual projection in both interoceptive and exteroceptive sense modalities, the case is made that the physical world as-perceived is a (...) construct of perceptual processing and, therefore, part of the contents of consciousness. A finding which requires a Reflexive rather than a Dualist or Reductionist model of how consciousness relates to the brain and the physical world. The physical world as-perceived may, in turn be thought of as a biologically useful model of the world as described by physics. Redrawing the boundaries of consciousness to include the physical world as-perceived undermines the conventional separation of the 'mental' from the physical', and with it the very foundation of the Dualist-Reductionist debate. The alternative Reflexive model departs radically from current conventions, with consequences for many aspects of consciousness theory and research. Some of the consequences which bear on the internal consistency and intuitive plausibility of the model are explored, e.g. the causal sequence in perception, representationalism, a suggested resolution of the Realism versus Idealism debate, and the way manifest differences between physical events as-perceived and other conscious events are to be construed. In the present paper I wish to challenge some of our most deeply-rooted assumptions about what consciousness is, by re-examining how consciousness, the human brain, and the surrounding physical world relate to each other. (shrink)

One of the things you learn if you read books and articles in (or about) cognitive science is that the brain does a lot of "filling in"--not filling in, but "filling in"--in scare quotes. My claim today will be that this way of talking is not a safe bit of shorthand, or an innocent bit of temporizing, but a source of deep confusion and error. The phenomena described in terms of "filling in" are real, surprising, and theoretically important, but it (...) is a mistake to conceive of them as instances of something being filled in, for that vivid phrase always suggests too much--sometimes a little too much, but often a lot too much. Here are some examples (my boldface throughout). (shrink)