Alpha oscillations mediate inhibitory control and perceptual transitions during binocular rivalry

Binocular rivalry is a visual phenomenon that involves alternating percepts despite stable input, providing a window into perceptual processing and neural dynamics. We examined changes in alpha band activity (8-13 Hz) using magnetoencephalographic imaging (MEG). Our time-frequency analysis demonstrates a decrease in alpha band power before the onset of rivalry alternations, indicating a reduction in inhibitory processing, permitting destabilization of the dominant percept. In contrast, an increase in alpha power was observed prior to participant's report of mixed percepts, suggesting heightened inhibitory processing associated with perceptual ambiguity. Directed connectivity analysis (phase transfer entropy) revealed enhanced feedback connectivity from parietal to early visual areas preceding perceptual dominance, which shifted toward feedforward connectivity following perceptual alternations. These findings suggest that alpha oscillations play a critical role in the excitation-inhibition balance that underlies perceptual stability during binocular rivalry and are further related to individual differences in perceptual experiences.