Differences between stereopsis, interocular correlation and binocularity.

In normal human subjects, evoked potentials in response to depth reversing two-color dynamic random-dot stereograms disappeared or were greatly reduced at equiluminance, whereas responses to shifts between patterns that were correlated and anticorrelated (for the two eyes) were, for most subjects, actually larger at equiluminance than at non-equiluminance. Responses were only slightly diminished at equiluminance to similar texture-shifting patterns that were identical to the two eyes. These results suggest that a significant fraction of cells with input from both eyes can respond to correlation/anticorrelation shifts, yet are not involved in stereopsis. Also, binocular rivalry may gate the responses of these binocular-nonstereoscopic units.