Changes in EEG alpha power induced by repetitive ipsi- and contralateral hand movements.

Changes in alpha activity induced by hand movements, both ipsi and contralateral to left brain hemisphere were studied. Seven channels of EEG (F3, C3, P3, O1, T3, T5 and CZ referred to nasion) were processed by a minicomputer. The values which correspond to three tasks (rest, right hand and left hand movement) were analyzed by means of an ANOVA of three factors. Our data bring us to the following conclusions: The two movements (left and right hand) cannot be differentiated by alpha band power in any electrode position and both of them decrease the alpha power significantly. This decreasing effect is not homogeneous in the whole hemisphere, being greater in the central area.