Scalp topography of power spectra changes of the EEG (relative to baseline from −1 to −0.6 s) averaged across all trials and participants.

Time in abscissa from −0.8 s to 0.8 s. Frequency in ordinate from 0 to 50 Hz at a resolution of 2 Hz. Movement onset occurs at s (solid black line in all graphs). Sensors above the contralateral and ipsilateral motor areas revealed a power increase in the slow wave range (4)Hz and a de-synchronization in the (8-12)Hz and (14-30)Hz frequency bands. Graph at the right lower corner represents the average across-sensors relative power spectra changes of the recorded EEG.