Abstract
Human visual system has an anistropy in sensitivity to the discrimination of depth curvature defined by binocular disparity depending on modulation directions. Shear curvature (depth modulation in vertical direction) is easier to perceive than compressive curvature (depth modulation in horizontal direction). To explore this anisotropy we measured the performance for concave-convex discrimination using random-dot stereogram with varied duration and density. Discrimination performance increased monotonically with duration increase for shear curvature. For compressive curvature, however, the performance first peaked at a short duration (33 ms). It, then, degraded for a while, and increased again at longer durations. The first peak probably reflects the local processing of disparity, and the second increase might reflect the global-integration processing.
