Responses of neurons in visual cortex (V1 and V2) of the alert macaque to dynamic random-dot stereograms.

A substantial proportion of both simple and complex neurons in the cortex subserving central vision are differentially sensitive to binocular disparity of isolated line patterns (local stereopsis), a sensitivity based on a positional disparity between the neuron's receptive fields in the two eyes. In addition, a subset of cortical neurons, nearly all complex neurons, responds to dynamic random-dot stereograms containing no depth cues other than disparity. These neurons are capable of signaling the correct binocular matches among a multitude of false matches in the stereograms (global stereopsis). The discovery of cyclopean neurons in striate cortex, at early stages of the processing neural network for stereoscopic vision provides a new insight of the basic neural mechanisms underlying binocular depth perception.