Subjective contours in the absence of local spatial and temporal correlation.

Abstract

Subjective contours provide an opportunity to explore the limits of correspondence matching in motion. A new class of subjective contour which is a by-product of motion processing is examined within the context of the dual process models of retinal motion processing proposed by Braddick (1980) and Anstis (1980), as well as the more recent first-order/second-order formulation proposed by Cavanagh and Mather (1989). These kinetically induced figures are created by displacing a surface defined by dots which change randomly from frame to frame over a static random dot background. Despite the fact that local form information is uncorrelated throughout the motion sequence, the resulting phenomenal percept is that of a "sparkling" surface which translates across the background. The results of five experiments were not, however, fully consistent with predictions based on either model. An extension of the criteria necessary for the long-range system to be operative would accommodate the data within the context of the short-range/long-range model, whereas a more detailed definition of the properties and relationships between second-order attributes would accommodate the data within the framework of the first-order/second-order model.