Behavioral evidence for visual perception of 3-dimensional surface structures in monkeys.

Human subjects perceive two crossing bars, one in front of the other, when shown a cross with disparity added to its horizontal limbs, and they also perceive neon-color spreading when shown a stereoscopic Redies-Spillmann figure. It has thus been hypothesized that the human visual system follows the principle of generic image sampling in reconstructing 3-dimensional (3-D) surface structures. Here we examine whether monkeys also perceive these surface structures. The results indicate that monkeys, like humans, perceive two crossing bars and neon-color spreading and suggest that the principle of generic image sampling may also be applied to visual perception in monkeys.