Abstract

There has been recent interest in comparing the efficiency with which chromatic and luminance information is processed in the visual system. This comparison has been made with many different tasks including spatial and temporal contrast sensitivity, stereopsis, motion, and vernier acuity. Performance is generally worse for isoluminant than isochromatic stimuli, which has led to the view that chromatic information is processed less efficiently than luminance information. However, the overlap in the spectral sensitivity of cones limits the the highest contrast that can be realized in the L and M cones with isoluminant stimuli, a limitation that does not apply to isochromatic gratings. We sought to determine how much of the difference between contrast sensitivity for isoluminant and isochromatic stimuli can be attributed to this overlap and how much to post-receptoral factors. It is well established that isoluminant and isochromatic contrast sensitivity differ at low spatial frequencies due to the presence of a low-frequency cut for isochromatic stimuli Our interest was to determine whether the performance at high spatial frequencies is also different.

© 1992 Optical Society of America