Koehler's satiation theory and Deutsch's neurophysiological model of figural after-effects
A lifetime of work by Gestalt psychologists has culminated in an electrical field theory of cerebral integration which represents an attempt to explain a number of visual phenomena and even provide a bridge between the general areas of perception and learning (Koehler, 1958, 1965; Koehler & Fishback, 1950a, 1950b; Koehler & Wallach, 1944). One of the main objections to this theory is that it is not based upon orthodox physiological principles. According to Prentice, for example, Koehler's theory is regarded as a radical departure from current physiological knowledge of the nervous system because it suggests "••• the importance of physical phenomena other than those that follow anatomical pathways" (1962, p. 46). In 1952 Osgood and Heyer presented a theory which they claimed could explain most of the visual phenomena of Koehler's theory, and which was based on known physiological principles. The logical consistency and neurophysiological assumptions of this theory have since been questioned (Deutsch, 1956), and these assumptions have never been subjected to experimental examination as has been the case with Koehler's theory (Day, Pollack & Seagrim, 1959). Using some of the most recent neurophysiological findings, Deutsch (1964) presented a model which was designed to account for the phenomena covered by the two earlier theories. At present, however, no experimental data are available either to evaluate this theory or to compare it with Koehler's or Osgood's models. Therefore the purpose of the present investigation is to test some of the predictions of this latest theoretical attempt and compare it with the earlier positions. Because most of the predictions of Koehler's satiation theory, Osgood's statistical theory and Deutsch's neurophysiological theory are made in terms of figural after-effects, the present investigations will be largely restricted to these phenomena. In the following sections these phenomena will be described and the three theories broadly outlined. Some of the predictions of these models and relevant experimental evidence will be discussed, and the results of experiments designed to test these predictions will be described. In the final section of this study these theories will be evaluated in the light of the present and earlier experimental results.
Doctor of Philosophy (Ph.D.)