title: Vertical-disparity gradients are processed independently in different depth planes.
abstract: We examined the effects of vertical-disparity gradients on apparent depth curvature of textured surfaces. In Experiment 1, vertical disparities induced expected curvatures when the surface had a horizontal disparity of < +/-40.34'. A central row of elements, lacking vertical disparities, ceased to have the same apparent curvature as the surface when the horizontal disparity between row and surface exceeded +/-5'. In Experiment 2, vertical disparities were not pooled between superimposed surfaces separated by horizontal disparities > +/-10'. Thus, vertical-disparity gradients are not pooled over depth for curvature perception. Our results suggest that vertical disparities are used to determine distances to surfaces directly, rather than to estimate vergence.
authors.affiliation: Centre for Vision Research, York University, 4700 Keele St., Toronto, Ont., M3J 1P3, Canada. pduke@yorku.ca
authors.forename: Philip A
authors.initials: PA
authors.lastname: Duke
authors.forename: Ian P
authors.initials: IP
authors.lastname: Howard
mesh_terms: D000328:Adult; D000368:Aged; D003463:Cues; D004215:Distance Perception / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D015357:Vision Disparity / Q000502:physiology*; D015348:Vision, Binocular / Q000502:physiology