In this paper, I critically assess the enactive account of visual perception recently defended by Alva Noë (2004). I argue inter alia that the enactive account falsely identifies an object’s apparent shape with its 2D perspectival shape; that it mistakenly assimilates visual shape perception and volumetric object recognition; and that it seriously misrepresents the constitutive role of bodily action in visual awareness. I argue further that noticing an object’s perspectival shape involves a hybrid experience combining both perceptual and imaginative elements (...) – an act of what I call ‘make-perceive.’. (shrink)

I survey some of the connections between the metaphysics of the relation between mind and matter, and quantum theory’s measurement problem. After discussing the metaphysics, especially the correct formulation of physicalism, I argue that two state-reduction approaches to quantum theory’s measurement problem hold some surprises for philosophers’ discussions of physicalism. Though both approaches are compatible with physicalism, they involve a very different conception of the physical, and of how the physical underpins the mental, from what most philosophers expect. And one (...) approach exemplifies a a problem in the definition of physicalism which the metaphysical literature has discussed only in the abstract. A version of the paper has appeared in Consciousness and Human Identity, ed. John Cornwell, OUP 1998. (shrink)

The plan for this volume emerged during the international Leipzig conference commemorating the centenary of the death of Gustav Fechner.

Recent philosophy of mind has tended to treat.

This volume presents a series of studies that expand laws, invariants, and principles of psychophysics beyond its classical domain of sensation.

Imagery has played an important, albeit controversial, role in the study of memory psychophysics. In this commentary we critically examine the available data bearing on whether pictorial based depictions of remembered perceptual events are activated and scanned in each of a number of different psychophysical tasks.

Advances in neuroscience implicate reentrant signaling as the predominant form of communication between brain areas. This principle was used in a series of masking experiments that defy explanation by feed-forward theories. The masking occurs when a brief display of target plus mask is continued with the mask alone. Two masking processes were found: an early process affected by physical factors such as adapting luminance and a later process affected by attentional factors such as set size. This later process is called (...) masking by object substitution, because it occurs whenever there is a mismatch between the reentrant visual representation and the ongoing lower level activity. Iterative reentrant processing was formalized in a computational model that provides an excellent fit to the data. The model provides a more comprehensive account of all forms of visual masking than do the long-held feed-forward views based on inhibitory contour interactions. (shrink)

In past and modern psychophysics there are several unresolved methodological and philosophical problems of human and animal perception, including the outstanding question of the relational basis of whole psychophysics. Here the main issue is discussed: if, and to what extent, there are viable bridges between the traditional “gestalt” oriented approaches and the modern perceptual-cognitive perspectives in psychophysics. Thereby the key concept of psychological “frame of reference” is presented by pointing to Hermann Ebbinghaus' geometric-optical illusions, on the one hand, and Max (...) Wertheimer's treatment of the traditional transposition phenomenon, on the other hand. A much-needed theoretical reorientation of future research may help to overcome the philosophical narrowness of present-day human and comparative psychophysics. (shrink)

We explore experimental methods used to study the phenomena of perceptual organization, first studied by the Gestalt psychologists. We describe an application of traditional psychophysics to perceptual organization and offer alternative methods. Among these, we distinguish two approaches that use multistable stimuli: (1) phenomenological psychophysics, in which the observer's response is assumed to accurately and directly reflect perceptual experience; and (2) the interference paradigm, in which an observer's response is evaluated as correct or incorrect because it pertains to a corrigible (...) task, but does not directly reflect the observer's experience. We show that phenomenological psychophysics can yield valuable information about perceptual organization and lends itself to the development of quantitative theory. We discuss some criticisms of the method and argue that the two approaches that use multistable stimuli are complementary. We also compare each of the approaches with traditional psychophysics. We conclude that the several methods are convergent. (shrink)

In the present paper the relation between objective and subjective time is studied from a neutral non-dualist perspective Adoption of the relational concept of time leads to fundamental problems of time measurement of the uniformity of time measures, and of a native measure of duration in subjective experience. Experimental data on discrimination and reproduction of time intervals are reviewed and relevant models of internal time representations are discussed. Special attention is given to the 'dual klepsydra model' (DKM)and to the outstanding (...) properties of the reproduction func- tion yielded by the DKM Time scales generated by a DKM-based reproduction mechanisms are studied It is shown that such 'klepsydraic clocks' generate time measures which are non-uniform with respect to objective time yet internally consistent within an ensemble of such clocks and in this sense 'quasi-uniform' . Competing concepts of subjective time and modeling principles of internal time representation are briefly discussed Some interesting parallels be- tween our psychophysical approach and E.A. Milne's treatment of the problem of uniform time are drawn in the Appendix. (shrink)

In Fechner's psychophysics, the 'mental' and the 'physical' were conceived as two phenomenal domains, connected by functional relations, not as two ontologically different realms. We follow the path from Fechner's foundational ideas and Mach's radical programme of a unitary science to later approaches to primary, psychophysically neutral experience (phenomenology, protophysics). We propose an 'integral psychophysics' as a mathematical study of law-like, invariant structures of primary experience. This approach is illustrated by a reinterpretation of psychophysical experiments in terms of perceptual situations (...) involving a constructed apparatus and an instructed subject. The problematic notion of 'measurement of sensation' is thus eliminated: 'sensations' are merely indices for classes of perceptually equivalent configurations (states of the apparatus) specified by the instruction. The locus of the measured is in the inter-subjectively shared, communicable world—not inside the subject's mind. Finally we discuss the role of integral psychophysics as a scientia prima , logically and methodically preceding physics and psychology. (shrink)