V1 interlaminar coherence decreases with interocular conflict

Resolving conflicting input from the two eyes is a fundamental challenge for the visual system. In the primary visual cortex (V1), such interocular conflict induces modest suppression of single neuron spiking, but the accompanying population-level dynamics remain poorly understood. Here we examined laminar multi-unit activity and interlaminar local field potential (LFP) coherence in macaque V1 during dichoptic stimulation and binocular rivalry flash suppression (BRFS). From laminar microelectrode recordings, we found that interocular conflict reliably reduces interlaminar coherence, particularly between granular and infragranular layers, suggesting altered temporal coordination across the cortical column. Strikingly, during BRFS, coherence remained reduced even when firing rates were unchanged. Moreover, interlaminar coherence is higher for perceptually dominant BRFS stimuli, indicating that coherence across V1 layers covaries with perceptual outcome in the absence of significant firing-rate differences. These findings show that the temporal dynamics of population coherence are a more stable signal of interocular conflict than spike rate modulation.