Features of EEG Activity Related to Realization of Cyclic Unimanual and Bimanual Hand Movements in Humans

In 10 tested dextral subjects, EEG activity was recorded during the performance of unimanual and bimanual cyclic movements of the hands and fingers. The movements corresponded to clenching the fingers into a fist and the subsequent unclenching of the fingers. The test consisted of four successive stages, the resting state, movement of the left hand, that of the right hand, and movement of both hands. The dependences between the spectral power and coherence of the respective EEG samples on the type of the test performed, on the type of the movement (uni- or bimanual), and on the laterality of the latter in the case of the unimanual movement were examined. The results obtained allow us to propose the following conclusions: (i) alpha and beta EEG rhythms are characterized by different functional importance with respect to manual motor activity; (ii) neural control of bimanual movements cannot be considered "a sum of the controls" of unimanual movements, and (iii) control of bimanual movements may be largely based on the control of the movement by a subdominant upper limb.