EVENT-RELATED COHERENCE AND EVENT-RELATED DESYNCHRONIZATION SYNCHRONIZATION IN THE 10 HZ AND 20 HZ EEG DURING SELF-PACED MOVEMENTS/

To investigate the activity of cortical regions in the control of move ment, we studied event-related desynchronization/synchronization (ERD/ ERS), event-related coherence (ERC), and phase coherence in 29-channel EEGs from 9 subjects performing self-paced movements of the right ind ex finger. Movement preparation and execution produced ERD over the se nsorimotor areas at 10 Hz and 20 Hz, followed by ERS. ERD corresponded spatiotemporally to an increase in coherence over the frontocentral a reas. For both frequency bands, ERD began over the left sensorimotor a reas and became bilateral at the time of movement onset. The coherence increase with frontal areas began in the left central areas and becam e symmetrical after EMG onset. The ERD and coherence increase was long er at 10 Hz than at 20 Hz. Phase coherence at 10 Hz showed a lead of a nterior regions to posterior regions throughout the time period, and a t 20 Hz showed a tendency toward zero phase delay corresponding with t he movement. EEG desynchronization parallels functional coupling over sensorimotor and frontal areas. Event-related coherence and phase cohe rence findings implicate the frontal lobes in control of movement plan ning and execution. The involvement of different frequency bands with different timings may represent parallel changes in the cortical netwo rk. (C) 1997 Elsevier Science Ltd.