Modeling binocular vision: loss of 3-D in the presence of rivalry requires a new approach

In a dichoptic stimulus, where one feature in one eye could participate in both rivalry and stereopsis with features in the other eye, 3D perception was lost intermittently. The periods of loss of 3D percept were positively correlated with the periods of rivalrous suppression, and the degree of difference in rivalrous suppression between the eyes, due to variable eye dominance, was positively correlated with the degree of loss of 3D percept. This suggested that because differential luminance between the eyes affects their dominance in rivalry, stereopsis in the presence of rivalry would be similarly affected, and we now suggest that it is. These results are not predicted by any of the presently popular accounts of how rivalry and 'fusion' coexist. Instead, it seems that rivalry and 'fusion' are not two modular processes and that rivalry and stereopsis are affected by the same factors within an interactive network.