QBI Neuroscience Seminar: Visual consciousness tracked with direct intracranial recording from low- and high-level visual cortices in humans and monkeys

Event Details

Date:

Wednesday, 04 July 2012

Time:

12:00 pm - 1:00 pm

Room:

Auditorium Level 7

UQ Location:

Queensland Brain Institute (St Lucia)

URL:

Event category(s):

Full Description:: Speaker: Associate Professor Naotsugu Tsuchiya
Laboratory for the neuronal basis of consciousness School of Psychology and Psychiatry, Monash University

Title: Visual consciousness tracked with direct intracranial recording from low- and high-level visual cortices in humans and monkeys

Abstract: 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 whole brain. However, if rapid interaction among neuronal populations in distant cortical areas is essential for consciousness, it is necessary to employ other methods such as intracranial electrocorticogram (ECoG) that can attain high spatiotemporal resolution with wide coverage of the brain. Here we report the results of ECoG experiments in four epilepsy patients and one monkey. We used Continuous Flash Suppression (CFS) to investigate the neuronal activity when ‘invisible’ stimuli broke interocular suppression. We found that wide spread activity in the visual cortex preceded up to 1-2 seconds before subjective reports of detection and that low-frequency band power in the visual and prefrontal cortex evoked at the onset of CFS predicted how long the suppression was going to last. We will discuss implication of these findings for the neuronal dynamics associated with consciousness.