INFLUENCE OF LUMINANCE FLICKER AND PURITY ON HETEROCHROMATIC BRIGHTNESS MATCHING AND HUE DISCRIMINATION - A POSTRECEPTORAL OPPONENT PROCESS

We have studied psychophysically the characteristics of the postrecept oral stage of visual processing, using heterochromatic brightness matc hing (HEM) between 540 and 600 nm, and hue discrimination between 565 and 585 nm, under differing luminance flicker (0-30 Hz) and excitation purity (1.0-0.1) conditions. The HEM curves exhibit deeper minima aro und 575 nm with decreasing purity. The minimum is generally most prono unced with a 3 Hz bicker and least pronounced with a 30 Hz flicker. Hu e discrimination ability is relatively insensitive to flicker and dete riorates at the lower purities. The HEM results for low purities can b e explained by the upper envelope of activities in PC- and MC-pathways . (C) 1997 Elsevier Science Ltd.