EFFECTS OF THE SPATIAL-FREQUENCY OF TEST AND REFERENCE STIMULI ON STEREO-THRESHOLDS

The perceived depth of adjacent regions of stereoscopic stimuli may be influenced, in part, by differences in the spatial frequency composit ion of adjacent stimuli. Consequently, it would be predicted that, if the test and reference stimuli differ in their spatial frequency compo sition, depth discrimination thresholds should be asymmetric about the retinal disparity of the reference stimulus. We measured depth discri mination thresholds with test and reference stimuli that differed by u p to 2 octaves in their spatial frequency composition. Stereothreshold s decreased as a function of spatial frequency to about 2-4c/deg and w ere then constant. However, in contrast to the predicted effects, our results show that, for the range of spatial frequencies used, differen ces of up to 2 octaves in spatial frequency, between test and referenc e stimuli, do not affect depth discrimination thresholds.