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Guest talk by Associate Professor Sylvain Baillet

Associate Professor Sylvain Baillet, Director - McConnell Brain Imaging Centre Montreal Neurological Institute, McGill University is visiting Aarhus and will give a guest talk

2013.11.21 | Henriette Blæsild Vuust

Date Wed 11 Dec
Time 14:30 16:00
Location DNC Auditorium, Aarhus University Hospital, Building 10G, Nørrebrogade 44, 8000 Aarhus C

The title of Sylvain Baillet's talk is:
Neural dynamics of cross-frequency coupling in the resting & active states


During the past decade, resting-state networks have been identified with fMRI and more recently, using MEG imaging. Yet, the neurophysiological mechanism explaining the production of these organized fluctuations remains to be uncovered. Here we show non-invasively with MEG source imaging that the nested dynamics of neural oscillations provide a support for long-range, default connectivity in the resting brain. In particular, we confirm that the occurrence of local high-frequency neural oscillations is coupled with the phase of slower fluctuations and demonstrate that it is a ubiquitous phenomenon across the human brain. We further show that this nesting mechanism of phase-amplitude coupling between neural oscillations accounts for the correlated variations of imaging signals from different brain regions that have been observed using other techniques in the resting brain so far. Overall, our results suggest that the mechanisms that reveal the brain's resting-state networks with fMRI are based on the cross-frequency coupling between the phase of low-frequency components and the amplitude of high- gamma oscillatory fluctuations.

We will discuss further this generic principle with experimental data illustrating how ongoing resting-state brain dynamics are perturbed by sensory stimulation.