Motion-Induced Illusory Contours: Priority of Global Aspects on Motion Perception

Abstract

The present work deals with the perception of illusory surfaces assessed by the apparent motion of equal, parallel, and equidistant vertical stripes. Particularly, the influence of a reduction in length of one single stripe was studied. Two alternative perceptions were reported by participants: (a) the stripes seemed to move in a plastic (nonrigid) fashion, or (b) an apparent illusory rectangle was perceived in motion at the top of a complete row of stripes, which appeared to move in a rigid fashion in the opposite direction. In both perceptions, the single shorter stripe lost its identity and was absorbed by the global pattern of stripes in motion. The tendency to maintain identity seems to regard first of all the whole structure. It was found that these perceptions depended on the velocity of presentation of stripes and on the size of the shorter stripe.