On the Relation between Cellular Sensitivity and Psychophysical Detection

Abstract

Recent interest in the parvocellular and magnocellular pathways within the primate visual system has a dual origin. Firstly, the physiology of these systems is of intrinsic interest. Some features appear unique to the primate, and are of relevance to wiring diagrams emerging from primate retinal anatomy. Secondly, there is abundant psychophysical evidence for the existence of chromatic and achromatic channels within the human visual system. The relationship of different cell types and systems to these channels has been controversial (see Shapley and Perry, 1986; Kaplan et al., 1990 for review). Although the parvocellular and magnocellular systems have been proposed as physiological substrates for the chromatic and achromatic channels (Crook et al, 1987; Lee et al, 1988; Lee et al., 1989a; Kaiser et al., 1990), there is evidence contrary to this viewpoint (e.g., Schiller et al., 1990). In this paper, I shall review physiological evidence relevant to certain standard psychophysical paradigms and consider some of the problems associated with specifying the substrates of performance from physiological data.