The Perceptual Elaboration of Stroboscopic Presentations

Abstract

When the middle one of 3 contiguous patterns is first exposed and then followed by the simultaneous exposure of its neighbors, O fails to perceive the first and characteristically reports an outward movement. This phenomenon, metacontrast, is found to be a function of the contiguity of patterns, interval between exposures, and brightness of patterns. The greater the brightness the shorter must be the inter-interval and vice versa. The phenomenon occurs if the center pattern is seen by one eye and the outer patterns by the other. The results point to a central theory involving a classifcatory and a dispositional process. O classifies the situation "by means of a rapid unconscious evaluation or physiological categorizing of perceptual data" and then the events of the sequence are assigned a role meaningful to the perceiver.