Visual information for object identity in apparent movement

Abstract

Apparent movement is used to examine the nature of the visual information which specifies object identity. Constructive feature-comparison theories rely on static formal information and predict that two phases of an apparent movement display must be featurally similar in order to appear as a single object in motion. An opposing Gibsonian model is based on abstract geometrical information and predicts that the two phases may differ radically in shape but must be ecologically transformable in order to be seen as a single object. The predictions are tested by presenting subjects with displays which are similar but not transformable, and transformable but dissimilar. Results show that the transformability of the display determines its perceived object identity, while featural similarity has no effect. An event theory of object identity is offered which claims that the affordance structure of an event, determined by geometric invariants specifies object identity. ma- © 1977 Psychonomic Society, Inc.