Increase of Late MEG Component by Perceptual Transition in Binocular Rivalry

Abstract

Binocular rivalry is a phenomenon created by presenting similar but different images for both eyes simultaneously. Many previous studies have investigated various brain responses to binocular rivalry. However, a response of the perceptual transition in binocular rivalry has not been clear yet. The present study aimed to measure the response of the perceptual transition in binocular rivalry using a motion rivalry stimuli with various motion angles. It is known that the perception of motion rivalry stimuli has two conditions depending on the angle between two motion directions. One is a rivalrous condition that cause binocular rivalry and the perceptual transition, and the other is a fused condition that does not cause them. Visual evoked fields (VEFs) were recorded with five healthy subjects using a 440-channel whole-head magnetoencephalogram (MEG) system. We classified trials to rivalrous or fused conditions, and calculated time averages of root mean square (RMS) values for every 100 ms in each condition. As a result, the time average of RMS values of the rivalrous condition were significantly larger than those of the fused condition after 400 ms post-stimulus. These results suggested that the perceptual transition in binocular rivalry increased the late MEG component.