Abstract

Instantaneous nonlinearities of the visual system have been assessed with a flashed increment threshold technique. Brief adapting lights (flashes) elevate the threshold for simultaneously presented test lights (probes). The shape of the probe threshold vs flash intensity function changes with adaptation state, and these changes can be related to the mechanisms of adaptation.¹ Here we assess adaptation processes of specific color mechanisms. We have previously (ARVO ’88) reported on nonlinearities in opponent and nonopponent color mechanisms at a constant state of adaptation. On a steady white adapting field, 50-ms probes and 500-ms flashes were varied along either an isochromatic radiance axis (light-dark), an isoluminant constant S cone axis (red-green), or an isoluminant constant L and Mcone axis (yellow-blue).

© 1988 Optical Society of America