Stimulus Information and Processing Mechanisms in Visual Space Perception

Abstract Most current models of the perception of visual space follow one of two courses. Some begin with a superficial analysis of the visual information contained in the light reflected from surfaces in a visual scene to the eye and then work out highly sophisticated information processing models of how that information is used. Others begin with a detailed analysis of the stimulus information available at the eye, and then provide only a superficial processing description, if they provide one at all. The empiricists, beginning with Helmholtz and followed by many others (e.g., Rock, Epstein, Leibowitz, and perhaps Hochberg) generally pursue the first approach, while Gibson and some of his disciples represent virtually all of the work on the second. It is my thesis that progress on space perception is doomed until we create a thoroughly Gibholtzian approach, in which the stimulus analysis is based on the information available from realistic scenes viewed by two-eyed, moving observers, and the processing analysis is based on how the richness of this stimulus information is extracted or picked up to construct representations of visual space in our heads. The present paper is in two parts. The first describes the major categories of available information contained in light, how those sources of information are related to each other, and how the perceiver acquires or comes into contact with such sources of information. The second part is concerned with how that information is processed or used. Finally, because we are able to perceive the layout of space when looking at photographs and paintings of scenes, and at sequences of pictures that create motion, the same pair of analyses - one for stimulus information and one for processing - is presented for cases in which one looks at flat displays of scenes and sequences of motion pictures.