1 - The Paradox of Depth Perception

Abstract

This chapter discusses the role of motion in depth perception by examining the origins of the ideas that underlie the current body of knowledge and theory in this area. The popular analogy between the eye and the camera has heavily influenced modern thinking about visual perception. The idea that perception begins with a flat, stationary image is implicit in much of the research and theory in this area. The view that the perception of motion in depth is at least as primary a perceptual experience as the perception of static flatness is a relatively new one. Partially for this reason and partially because of the greater technical difficulty of research in that area, research on motion in depth perception is also relatively new. Much of the research on depth perception currently reported is presented in terms of cues to depth. The homunculus idea is reflected in the tendency to regard the discovery of the sources of information required for accurate perception as the total problem of the perceptual researcher. It is as if a homunculus, once given the necessary information, can be counted on to make the appropriate judgments. The problem of considering the manner in which the information is processed has not been given adequate attention. Perceptual processes exist that operate on incoming information, leading to accurate perceptions of the external world. These processes are inappropriate to certain stimulus conditions leading to what have been called illusions.