Innate and Environmental Factors in the Development of Visual Form Perception

Is the perception of form innate? Since the analysis of the question by Locke in his Essay Concerning Human Understanding (1690) and by Berkeley in his Essay Towards a New Theory of Vision (1709), it has been widely assumed that the perception of primitive sensations such as color or light intensity is innate, but that form perception is acquired slowly through visual experience. It was recognized, first, that the retinal image represents a two-dimensional projection of a three-dimensional world, and hence could supply information from which the third dimension had to be inferred. Secondly, it was understood that any object of stimulation had a nonunique relationship to any retinal image, since conditions of illumination, distance of the object, and the orientation of the receptor organ (e.g., eye and head movements) were constantly changing. It was thought likely that considerable experience was required to discover the underlying invariances inherent in what William James called the booming, buzzing confusion of stimulation projected onto the proximal receptor surface. The perception of a line, given a projected linear array of light dots projected onto the retina, was for empiricists not a simple, innately given competence. Rather, they believed an organism had to experience those light dots simultaneously so that associations could form between the neural representatives of those light dots. Empiricism has retained its theoretical vigor, especially following Hebb’S neurophysiological formalization of its principles (1949). The present chapter, Blakemore’S (this volume), and Haith’S (this volume) document the continuing wealth of behavioral and neurophysiological research which Empiricism has stimulated.