title: Size-distance invariance: kinetic invariance is different from static invariance.
abstract: The static form of the size-distance invariance hypothesis asserts that a given proximal stimulus size (visual angle) determines a unique and constant ratio of perceived object size to perceived object distance. A proposed kinetic invariance hypothesis asserts that a changing proximal stimulus size (an expanding or contracting solid visual angle) produces a constant perceived size and a changing perceived distance such that the instantaneous ratio of perceived size to perceived distance is determined by the instantaneous value of visual angle. The kinetic invariance hypothesis requires a new concept, an operating constraint, to mediate between the proximal expansion or contraction pattern and the perception of rigid object motion in depth. As a consequence of the operating constraint, expansion and contraction patterns are automatically represented in consciousness as rigid objects. In certain static situations, the operation of this constraint produces the anomalous perceived-size-perceived-distance relations called the size-distance paradox.
authors.affiliation: Department of Psychology, Brandeis University, Waltham, MA 02254-9110.
authors.forename: M
authors.initials: M
authors.lastname: Hershenson
mesh_terms: D003867:Depth Perception / Q000502:physiology; D004215:Distance Perception / Q000502:physiology*; D005260:Female; D005556:Form Perception / Q000502:physiology; D006801:Humans; D007700:Kinetics; D008297:Male; D012858:Size Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*