S6-5: Visual Consciousness Tracked with Direct Intracranial Recording from Early and High-Level Visual Cortices in Humans and Monkeys

Key insights about the neuronal correlates of consciousness have been gained by electrophysiological recording of single neurons from a particular area or by recording of indirect fMRI signals from the whole brain. However, if rapid interaction among neuronal populations in distant cortical areas is essential for consciousness, other methods such as intracranial electrocorticogram (ECoG) that can attain both requirements are necessary. Here we report the results of ECoG experiments in three epilepsy patients and one monkey. We used Continuous Flash Suppression to investigate the neuronal activity when ‘invisible’ stimuli broke interocular suppression. We found that widespread activity in the visual cortex preceded up to 1–2 s before subjective reports of detection and that alpha-band activity in the visual cortex induced by the initial flashes predicted how long the suppression was going to last. We will discuss implication of these findings for the neuronal dynamics associated with consciousness