Assessing directionality of neural communication from macroscopic human brain signals

old_uid3433
titleAssessing directionality of neural communication from macroscopic human brain signals
start_date2007/11/12
schedule12h-13h
onlineno
summaryInduced gamma-band-responses (iGBRs; oscillations >30Hz) were repeatedly found to be modulated by familiar and unfamiliar objects in macroscopic human brain signals (MEG/EEG). This frequency-specific power change seems to indicate the dynamic formation of local neuronal assemblies during the activation of cortical object representations. As analytically power increase merely reflects the neural response of a single location, phase-synchrony was introduced to investigate the formation of large-scale networks between spatially distant brain sites. However, if we are interested in how distinct brain sites interact (to uncover the temporal hierarchy between them), classical phase-synchrony does not suffice. The current report will be focused on how the directionality of oscillatory interactions between brain sources can be assessed on the basis of a multivariate Granger-Causality coupling-measure. Specifically, this report should illustrate that uncovering the directionality of cortical information flow (feed-forward/-backward) may shed new light on cortical mechanisms of human object recognition
responsiblesBaillet