STEREOPSIS FROM INTEROCULAR SPATIAL-FREQUENCY DIFFERENCES IS NOT ROBUST

Based on data obtained using one-dimensional noise patterns, Tyler & S utter (1979). (Vision Research, 19, 859-865) concluded that stereoscop ic tilt can result from an interocular spatial frequency difference in the absence of consistent horizontal disparity, We tested stereopsis using two-dimensional random-dot patterns that were bandpass filtered to contain 1.0 octave bands of spatial frequency with means that diffe red between the two eyes. With vertical, one-dimensional stimuli we re plicated the results of Tyler and Sutter. However, stereoscopic tilt w as not perceived based on spatial frequency differences alone when the monocular images contained as little as a +.-14 deg range of orientat ion variation. In addition, model simulations demonstrate that the mod est stereoscopic performance produced by interocular spatial frequency differences in one-dimensional noise patterns are predicted by random disparity correlations at the pattern edges, These observations lead to the conclusion that stereopsis from frequency differences in the ab sence of pointwise disparity correlations does not reflect a special p rocessing capability of human vision but is an artifact associated wit h one-dimensional stimuli, As such, it plays no role in stereoscopic a nalysis of the natural environment. Copyright (C) 1996 Published by El sevier Science Ltd.