Abstract
In stereo pictures, objects and people often appear flat like cardboard cut-outs. Previous study suggests that this phenomenon occurs because of near viewing distance and disparity discontinuity between objects and backgrounds. In experiment 1, we investigated whether the inhibition of depth perception from disparity discontinuity is caused by depth contrast or binocular rivalry. The results show that the inhibition is caused by lateral inhibition of classical center-surround mechanism, which underlie depth contrast effect. Thus, the mechanism of depth contrast is analogous to those of luminance domain. In experiment 2, the effect of vergence angles on disparity detection was investigated. In results, it is more sensitive to disparity when vergence angle becomes smaller. This results suggest that the sensitivity of disparity is modulated by vergence. Because binocular disparity vary inversely with the square of the distance, this hypothesis is ecologically valid to keep depth constancy.
