Cooperative neural processes involved in stereoscopic acuity

• DOI: 10.1007/bf00238525
• Publication Date: 2004-09-10T01:52:59Z
• Authors: G. Westheimer
• Keywords: Discrimination Learning; Depth Perception; 03 medical and health sciences; 0302 clinical medicine; Psychophysics; Visual Acuity; Humans; Fixation, Ocular; Dominance, Cerebral; Retina

Results of psychophysical experiments are reported showing that synchrony, appropriate relative placement, and absence of standing disparity are important conditions to be met by members of a target configuration if they are to participate in the cooperative neural processes leading to the best disparity discrimination. Consecutive binocular presentation of the members of a stereo target decreases stereoacuity by a factor of about 10, and a step disparity displacement of a single line target needs to be larger still to be detected as a depth stimulus. A standing disaprity of even one minute of arc at least doubles the disaprity disxrimination threshold. It is postulated that a differencing mechanism operates on the depth signal of individual features; the temporal and spatial optima of target presentation for stereoscopic acuity outline the character of the concerned operations.