Abstract
A theory of efficient stereo coding [2] predicts that, in a natural visual environment, where the ocular correlation of the input depends on stimulus orientations, the striate cortical cells are more likely binocular when selective to horizontal rather than vertical orientations. A psychophysical experiment was designed to test this prediction. The interocular transfers of simultaneous orientation contrast at near horizontal and vertical orientations were measured. This measure was used to access the binocularity of the underlying cells. It turned out that in the natural stereovisual environment, the transfers for horizontal orientations were larger than that for vertical case. And in the unnatural stereo experimental environment, where the binocular correlation is the same for vertical and horizontal orientations, the transfer for the horizontal orientation was almost equal to that in the corresponding vertical case. These results are consistent with the theoretical prediction.