Online research in philosophy

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.

Since the founding of psychophysics in the latter half of the nineteenth century, controversy has raged over the subject matter of psychophysical laws. Originally, Fechner characterized psycho physics as the science describing the relation between physical magnitudes and the sensations these magnitudes produce in us. Today many psycho-physicists would deny that sensation is or could be a topic of psycho-physical investigation. I consider Savage's (1970) influential objections to the possibility of such an investigation and argue that they depend upon (i) holding psychophysics to higher standards than those to which we hold other sciences; and (ii) misrepresenting Fechner's stated goals for psychophysics.

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.

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.