title: A counterexample to the rigidity assumption in the visual perception of structure from motion.
abstract: It has been proposed that the human visual system prefers perceptions of objects that are rigid or undergo minimum form change. A counterexample is presented in which a rigid two-dimensional figure rotating in the frontal plane is perceived as a distorting three-dimensional shape. It is argued that this perception results from the stimulation of automatic processes for perceiving size change, and that these processes are not subject to a general rigidity assumption.
mesh_terms: D003867:Depth Perception; D004193:Discrimination Learning; D005556:Form Perception; D006801:Humans; D009039:Motion Perception; D009903:Optical Illusions; D011601:Psychophysics