Abstract

Most laboratory research on color perception involves monocular experiments. With monocular stimuli, the effects of central mechanisms that affect color perception in natural viewing may be missed or misinterpreted, since central mechanisms may respond differently when receiving neural signals from both eyes. Using binocular and haploscopic adapting fields, some properties of central mechanisms have been determined. One fundamental result is the qualitatively different effect of adapting the contralateral eye, compared with the usual monocular condition where the test and adapting lights are seen by the same eye. For example, long-wavelength adaptation of the contralateral eye causes a test to appear more reddish; this contrasts with the well-known effect of the same adapting field in a monocular experiment, where it causes the test to appear more greenish. Measurements also show that changes in color appearance caused by contralateral adaptation cannot be explained by a simple contribution to hue from the contralateral stimulus. Further, studies in which both eyes are adapted have revealed the complex nature of central mechanisms: binocular adaptation cannot be accounted for by combining the effect of adapting only the test eye with the effect of adapting only the contralateral eye. These and other results reveal an important role of central mechanisms. A function of central mechanisms consistent with the results is integration of disparate signals from the two eyes by a process that tends toward color constancy.

© 1985 Optical Society of America