title: Perceived orientation of axis of rotation in structure-from-motion.
abstract: Perceived orientation of axis of rotation and accuracy in discriminating fixed-axis from nonfixed-axis rotations were investigated for orthographic projections of three-dimensional rotating objects. The principal findings were (a) the slant of the axis of rotation was systematically misperceived; (b) in both two-view and multiview displays, the perceived slant of the axis of rotation was well-predicted by the ratio between the deformation (a property of the first-order optic flow) and the component parallel to the image plane of the global velocity vector; (c) if this ratio was kept constant in each frame transition of the stimulus sequence (or it was varied), then the stimuli tended to be judged as fixed-axis rotations (or as nonfixed-axis rotations), regardless of whether they simulated a fixed-axis rotation or not; and (d) the tilt of the axis of rotation was perceived in two-view displays with a very small error.
authors.affiliation: Cognitive Technology Laboratory, AREA Science Park, Trieste, Italy. caudek@uts.univ.trieste.it
authors.forename: C
authors.initials: C
authors.lastname: Caudek
authors.forename: F
authors.initials: F
authors.lastname: Domini
mesh_terms: D000328:Adult; D001288:Attention; D003867:Depth Perception; D004193:Discrimination Learning; D005260:Female; D006801:Humans; D007092:Imagination; D008297:Male; D009039:Motion Perception; D009903:Optical Illusions; D009949:Orientation; D011601:Psychophysics