Monkey contrast threshold for aperiodic patterns.

A monkey's and a human subject's threshold responses were measured for single- and double-bar patterns of high spatial frequency. The observed values were compared to predicted values which were derived from each subject's contrast sensitivity function. A theoretical peak-to-trough threshold mechanism was assumed in the calculations. The threshold predictions, which are couched in the assumption that the spatial visual system is linear near its threshold, were found to be close to observed values. The results are interpreted to suggest that the monkey visual system analyzes spatial information in qualitatively and quantitatively similar ways to human, and that a linear theory may be used for analyses of primate vision.