Electrical activity in primary visual area due to interocular suppression

Under binocular rivalry conditions, evoked potentials to lower hemifield stimulation are more positive for the dominant than for the suppressed eye between 100 and 300 ms. However, this pattern reverses when the upper hemifield is stimulated, suggesting a neural source in V1 for this endogenous potential (rivalry-related potential, RRP). Here we investigated the functional significance of the RRP using an interocular suppression procedure. We replicated the RRP polarity reversal for upper versus lower hemifield stimulation and showed that the RRP reflects differences in processing during dominance and suppression and not shifts in dominance.