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Articles 1 - 4 of 4
Full-Text Articles in Cognition and Perception
Perceived Depth In Non-Transitive Stereo Displays, Bart Farell, Cherlyn J. Ng
Perceived Depth In Non-Transitive Stereo Displays, Bart Farell, Cherlyn J. Ng
Biomedical and Chemical Engineering - All Scholarship
The separation between the eyes shapes the distribution of binocular disparities and gives a special role to horizontal disparities. However, for one-dimensional stimuli, disparity direction, like motion direction, is linked to stimulus orientation. This makes the perceived depth of one-dimensional stimuli orientation dependent and generally non-veridical. It also allows perceived depth to violate transitivity. Three stimuli, A, B, and C, can be arranged such that A > B (stimulus A is seen as farther than stimulus B when they are presented together) and B > C, yet A ≤ C. This study examines how the visual system handles the depth of A, …
Perceived Depth In Non-Transitive Stereo Displays, Bart Farell, Cherlyn J. Ng
Perceived Depth In Non-Transitive Stereo Displays, Bart Farell, Cherlyn J. Ng
Biomedical and Chemical Engineering - All Scholarship
The separation between the eyes shapes the distribution of binocular disparities and gives a special role to horizontal disparities. However, for one-dimensional stimuli, disparity direction, like motion direction, is linked to stimulus orientation. This makes the perceived depth of one-dimensional stimuli orientation dependent and generally non-veridical. It also allows perceived depth to violate transitivity. Three stimuli, A, B, and C, can be arranged such that A > B (stimulus A is seen as farther than stimulus B when they are presented together) and B > C, yet A 6 C. This study examines how the visual system handles the depth of A, …
Contour Completion Through Depth Interferes With Stereoacuity, Dawn Vreven, Suzanne Mcvee, Preeti Verghese
Contour Completion Through Depth Interferes With Stereoacuity, Dawn Vreven, Suzanne Mcvee, Preeti Verghese
Dawn L Vreven
Local disparity signals must interact in visual cortex to represent boundaries and surfaces of three-dimensional (3D) objects. We investigated how disparity signals interact in 3D contours and in 3D surfaces generated from the contours. We compared flat (single disparity) stimuli with curved (multi-disparity) stimuli. We found no consistent differences in sensitivity to contours vs. surfaces; for equivalent amounts of disparity, however, observers were more sensitive to flat stimuli than curved stimuli. Poor depth sensitivity for curved stimuli cannot be explained by the larger range of disparities present in the curved surface, nor by disparity averaging, nor by poor sensitivity to …
3d Shape Discrimination Using Relative Disparity Derivatives, Dawn Vreven
3d Shape Discrimination Using Relative Disparity Derivatives, Dawn Vreven
Dawn L Vreven
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.