This paper looks at two puzzles raised by the phenomenon of inattentional blindness. First, how can we see at all if, in order to see, we must first perceptually attend to that which we see? Second, if attention is required for perception, why does it seem to us as if we are perceptually aware of the whole detailed visual field when it is quite clear that we do not attend to all that detail? We offer a general framework for thinking (...) about perception and perceptual consciousness that addresses these questions and we propose, in addition, an informal account of the relation between attention and consciousness. On this view, perceptual awareness is a species of attention. (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)

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)

In this important book, Susan Hurley sheds new light on consciousness by examining its relationships to action from various angles. She assesses the role of agency in the unity of a conscious perspective, and argues that perception and action are more deeply interdependent than we usually assume. A standard view conceives perception as input from world to mind and action as output from mind to world, with the serious business of thought in between. Hurley criticizes this picture, and considers how (...) the interdependence of perceptual experience and agency at the personal level (of mental contents and norms) may emerge from the subpersonal level (of underlying causal processes and complex dynamic feedback systems). Her two-level view has wide implications, for topics that include self-consciousness, the modularity of mind, and the relations of mind to world. The self no longer lurks hidden somewhere between perceptual input and behavioral output, but reappears out in the open, embodied and embedded in its environment. Hurley traces these themes from Kantian and Wittgensteinian arguments through to intriguing recent work in neuropsychology and in dynamic systems approaches to the mind, providing a bridge from mainstream philosophy to work in other disciplines. Consciousness in Action is unique in the range of philosophical and scientific work it draws on, and in the deep criticism it offers of centuries-old habits of thought. (shrink)

A collection of works, many of them classics, on the orthodox view of visual perception.

(1) The induced colours led to perceptual grouping and pop-out, (2) a grapheme rendered invisible through ‘crowding’ or lateral masking induced synaesthetic colours — a form of blindsight — and (3) peripherally presented graphemes did not induce colours even when they were clearly visible. Taken collectively, these and other experiments prove conclusively that synaesthesia is a genuine percep- tual phenomenon, not an effect based on memory associations from childhood or on vague metaphorical speech. We identify different subtypes of number–colour synaesthesia (...) and propose that they are caused by hyperconnectivity between col- our and number areas at different stages in processing; lower synaesthetes may have cross-wiring (or cross-activation) within the fusiform gyrus, whereas higher synaesthetes may have cross-activation in the angular gyrus. This hyperconnec- tivity might be caused by a genetic mutation that causes defective pruning of con- nections between brain maps. The mutation may further be expressed selectively (due to transcription factors) in the fusiform or angular gyri, and this may explain the existence of different forms of synaesthesia. If expressed very diffusely, there may be extensive cross-wiring between brain regions that represent abstract concepts, which would explain the link between creativity, metaphor and synaesthesia (and the higher incidence of synaesthesia among artists and poets). Also, hyperconnectivity between the sensory cortex and amygdala would explain the heightened aversion synaesthetes experience when seeing numbers printed in the ‘wrong’ colour. Lastly, kindling (induced hyperconnectivity in the temporal lobes of temporal lobe epilepsy [TLE] patients) may explain the purported higher incidence of synaesthesia in these patients. We conclude with a synaesthesia-based theory. (shrink)

Almost everyone who has a limb amputated will experience a phantom limb--the vivid impression that the limb is not only still present, but in some cases, painful. There is now a wealth of empirical evidence demonstrating changes in cortical topography in primates following deafferentation or amputation, and this review will attempt to relate these in a systematic way to the clinical phenomenology of phantom limbs. With the advent of non-invasive imaging techniques such as MEG (magnetoencephalogram) and functional MRI, topographical reorganization (...) can also be demonstrated in humans, so that it is now possible to track perceptual changes and changes in cortical topography in individual patients. We suggest, therefore, that these patients provide a valuable opportunity not only for exploring neural plasticity in the adult human brain but also for understanding the relationship between the activity of sensory neurons and conscious experience. We conclude with a theory of phantom limbs, some striking demonstrations of phantoms induced in normal subjects, and some remarks about the relevance of these phenomena to the question of how the brain constructs a 'body image.'. (shrink)

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)

The paper proposes a way of bridging the gapbetween physical processes in the brain and the ''''felt''''aspect of sensory experience. The approach is based onthe idea that experience is not generated by brainprocesses themselves, but rather is constituted by theway these brain processes enable a particular form of''''give-and-take'''' between the perceiver and theenvironment. From this starting-point we are able tocharacterize the phenomenological differences betweenthe different sensory modalities in a more principledway than has been done in the past. We are also (...) ableto approach the issues of visual awareness andconsciousness in a satisfactory way. Finally weconsider a number of testable empirical consequences,one of which is the striking prediction of thephenomenon of ''''change blindness''''. (shrink)

Functionalism, a philosophical theory, has empirical consequences. Functionalism predicts that where systematic transformations of sensory input occur and are followed by behavioral accommodation in which normal function of the organism is restored such that the causes and effects of the subject's psychological states return to those of the period prior to the transformation, there will be a return of qualia or subjective experiences to those present prior to the transform. A transformation of this type that has long been of philosophical (...) interest is the possibility of an inverted spectrum. Hilary Putnam argues that the physical possibility of acquired spectrum inversion refutes functionalism. I argue, however, that in the absence of empirical results no a priori arguments against functionalism, such as Putnam's, can be cogent. I sketch an experimental situation which would produce acquired spectrum inversion. The mere existence of qualia inversion would constitute no refutation of functionalism; only its persistence after behavioral accommodation to the inversion would properly count against functionalism. The cumulative empirical evidence from experiments on image inversion suggests that the results of actual spectrum inversion would confirm rather than refute functionalism. (shrink)

binding of colour and alphanumeric form in synaesthesia. Nature 410.

Susan Hurley has attacked the ''Duplication Assumption'', the assumption thatcreatures with exactly the same internal states could function exactly alike inenvironments that are systematically distorted. She argues that the dynamicalinterdependence of action and perception is highly problematic for the DuplicationAssumption when it involves spatial states and capacities, whereas no such problemsarise when it involves color states and capacities. I will try to establish that theDuplication Assumption makes even less sense for lightness than for some ofthe spatial cases. This is due (...) not only to motor factors, but to the basic physicalasymmetry between black and white. I then argue that the case can be extendedfrom lightness perception to hue perception. Overall, the aims of this paper are:(1) to extend Susan Hurley''s critique of the Duplication Assumption; (2) to argueagainst highly constrained versions of Inverted Spectrum arguments; (3) to proposea broader conception of the vehicle for color perception. (shrink)

An interview with Anthony Freeman, in which one of the original authors of ‘The Science of Art’ [JCS, 6, No. 6/7, 1999] responds to to ongoing commentary.

Hurley’s is a difficult book to work through—partly because of its length and the complexity of its arguments, but also because each of the ten essays of which it is composed has a rather different starting point and focus, and because few of her arguments achieve real closure. Essay 2 discusses competing interpretations of Kant, essay 4 articulates nonconceptual forms of self-consciousness, essay 5 offers fresh interpretations of commissurotomy patients’ behavior, essay 6 develops an objection to Wittgenstein on rule following, (...) essay 8 attacks an alleged assumption of externalism, and chapter 10 explores the possibility of combining a “motor theory” and a “control theory” of perception. This is a very rich brew, and at least half the challenge this book presents consists in discerning its central argument and conclusion with enough precision to bring criticism to bear. (shrink)

We all know about the vehicle/content distinction (see Dennett 1991a, Millikan 1991, 1993). We shouldn't confuse properties represented in content with properties of vehicles of content. In particular, we shouldn't confuse the personal and subpersonal levels. The contents of the mental states of subject/agents are at the personal level. Vehicles of content are causally explanatory subpersonal events or processes or states. We shouldn't suppose that the properties of vehicles must be projected into what they represent for subject/agents, or vice versa. (...) This would be to confuse the personal and subpersonal levels. (shrink)