Stereopsis with large disparities: Discrimination and depth magnitude

Depth discrimination and perceived depth magnitude (indicated by a manual pointing response) were studied for disparities from 0.5° to 8°. For briefly exposed targets, discrimination and depth magnitude yield somewhat different functions of disparity. Discrimination begins to decline when depth magnitude is still increasing. This suggests that the variance of the depth signal increases faster than the magnitude of the signal. This result is consistent with the notion that stereoscopic processing involves the pooling of the activity of disparity detectors.