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Abstract

When presented with disparate visual stimuli to corresponding retinal locations, the perceptual experience of a subject vacillates across time between the two sensory signals. This phenomenon, called binocular rivalry allows disentangling sensory stimulation from conscious awareness and has therefore been instrumental to unravelling the neural correlates of conscious perception. Probing various regions of the macaque brain while they are presented with incongruent visual input has revealed that the proportion of feature selective neurons whose activity correlates with conscious perception increases as one progresses in the visual cortical hierarchy, peaking in temporal and prefrontal cortices. Given the role of prefrontal cortex in mediating task related behavior, recent theoretical and experimental approaches propose utilizing no-report paradigms so as to distill the true correlates of perception from those related to manual reports and task monitoring. To this end, we conducted an electrophysiological investigation of the ventrolateral prefrontal cortex in monkeys trained to passively fixate, while they experienced binocular rivalry, instigated with oppositely drifting, sinusoidal gratings presented to the two eyes. Optokinetic nystagmus elicited at any given time served as an objective indicator of the ongoing percept. We found robust modulation in visually selective spiking activity recorded from the prefrontal cortex contingent on the animal’s perception. Moreover, the magnitude of these modulations was comparable to the activity elicited in response to presentation of monocular visual input. These results suggest that the spiking activity in the prefrontal cortex is modulated in accordance with conscious perception in a no report binocular rivalry paradigm.