Binocular rivalry, brain stimulation and bipolar disorder
Mechanistic understanding of binocular rivalry (BR) has drawn upon psychophysical, electrophysiological and brain-imaging studies. The first brain stimulation approach occurred in the late 1990s and assessed a new mechanistic proposal, the interhemispheric switch (IHS) hypothesis. Both caloric vestibular stimulation (CVS) and transcranial magnetic stimulation (TMS) modulated rivalry predominance when applied unilaterally. We describe the IHS model, its genesis and the brain stimulation evidence on which it rests. We also review more recent CVS and TMS rivalry studies, and discuss the findings of slow BR in bipolar disorder (BD) and genetic contribution to individual variation in BR rate. Finally, we describe a recent Drosophila model that can shed light on genetic, molecular and neurophysiological aspects of both BR and BD.