PHASIC INHIBITION OF THE LIGHT REFLEX OF THE PUPIL DURING RETINAL RIVALRY

Abstract

Retinal rivalry was produced in normal subjects by presenting the 2 eyes with different pictures in a stereoscope. The latter was arranged to allow the experimenter to watch the pupils of the subject under magnification. In the center of the picture viewed by one eye of the subject, a short intense foveal flash of light could be given. With flash intensity in the threshold region of the pupillary light reflex, the pupils reacted more often if the flash arrived during dominance of the receiving fovea than if it arrived during suppression. The difference was statistically significant. Since the only known synapses common to the visual path and the path of the pupillary light reflex are in the retina, the expt. suggests a phasic inhibition of the retina proper during retinal rivalry.