3D shape discrimination using relative disparity derivatives.
Three-dimensional (3D) shape discrimination could be achieved using relative disparity signals or it could be achieved using a higher-order disparity derivative detector. Two 3D shape discrimination tasks were used to distinguish between these possibilities: a within-shape task and a between-shape task. Disparity thresholds were larger when discriminating within the same shape than when discriminating between shapes. More importantly, within-shape discriminations were dependent on the pedestal disparity (distance from fixation) whereas between-shape discriminations were not. The results suggest that a mechanism sensitive to higher-order disparity derivatives can achieve discrimination between different 3D shapes.
Vreven
Dawn
D
Department of Psychology, University of Wisconsin Oshkosh, 800 Algoma Blvd., Oshkosh, WI 54901, USA. vreven@uwosh.edu <vreven@uwosh.edu>
D004192:Discrimination, Psychological; D005403:Fixation, Ocular; D005556:Form Perception; D006801:Humans; D010775:Photic Stimulation / Q000379:methods; D011594:Psychometrics; D011601:Psychophysics; D012684:Sensory Thresholds; D012858:Size Perception; D015357:Vision Disparity; D015348:Vision, Binocular