Some Influences of past Experience upon the Perceptual Thresholds of Visual Form

Since the era of Helmholtz and Hering experimental psychologists concerned with the problems of visual form perception have tended to maintain themselves in two separate theoretical camps: those who stress the importance of past experience as the major non-stimulus determinant of perceptual events; and those who regard innate properties of the stimulated organism as primary factors. As traditional associationistic theory waxed strong, so did the application of empiricist doctrine to the explanation of perceptual events. With the development of Gestalttheorie, the alternate view gained favor. Gottschaldt, for example, completely rejected experience alone as a significant factor in subsequent perceptions.' Its frequent apparent effect he attributed to the concomitant influence of organizational factors and expectancy. Gottschaldt's extreme position has led to severe criticism of his theoretical interpretations and, more importantly, to a series of investigations that have demonstrated the operation of experience factors under conditions similar to those employed by Gottschaldt as well as in other experimental situations.2 Most of the experiments, however, have been concerned almost exclusively with ascertaining whether experience is a determinant of perception. With this established, none have attempted to explore the effects of differ-