The Manipulative Ability of the Visual System and the Problem of Image Invariance

Abstract

Repeated investigations of perception have shown conclusively that the objects with which behavior must be reconciled give completely different informative stimuli under different conditions of observation, so that the subject’s task is to decode the object as perceived or to construct a perceptual model on its basis. To construct such a perceptual model, and to compare it with the original, special activity is required. Adequacy of perception, according to some workers, is achieved by the fact that impressions from objects lying considerable distances away, in unusual aspects, or in unusual lighting, are transformed into something normal, just as if the subject had in fact brought the object perceived closer to the distance of optimal vision, had turned its frontal plane perpendicularly to the axis of vision, or transferred it for convenience of examination into more usual and favorable conditions of illumination.