THE SYNCHRONIZATION BETWEEN BRAIN-AREAS UNDER MOTOR INHIBITION PROCESS IN HUMANS ESTIMATED BY EVENT-RELATED EEG COHERENCE

To investigate the functional connection of brain areas under motor in hibition, the event-related coherence (ERCoh) of the electroencephalog ram (EEG) was calculated for 10 subjects who were asked to perform a v isual discrimination (GO/NO-GO) task. The subjects were instructed to push (GO) or not to push (NO-GO) a micro-switch according to different visual stimuli. Twenty-one-channel scalp EEGs were recorded and the s urface Laplacians were calculated at F3, F4, C3, C4, P3 and P3 using t he source derivation method. The time-courses of the inter- and intra- hemispheric coherence were calculated using the fast Fourier transform for each condition (GO or NO-GO), and were compared statistically bet ween the two conditions. The results suggest that the ERCoh under the NO-GO condition consisted of two components: a band synchronization be tween bilateral frontal areas and theta band synchronization among bil ateral frontal, central and parietal areas. It is likely that the form er is related directly to the decision not to move, and the latter is related to the motor inhibition process. (C) 1998 Elsevier Science Ire land Ltd. All rights reserved.