NINETEEN-CHANNEL EEG was recorded with closely spaced electrodes overlaying the left sensorimotor cortex during self-paced, voluntary right finger movements. Three right-handed people served as subjects. The EEG was analysed in the 10 Hz band (10–12 Hz) and in four 40 Hz bands (34–36, 36–38, 38–40, 40–42) by calculation of ERD time courses and ERD maps, whereby a ERD is characterized by a movement-related band power decrease. In all three subjects a close to C3 localized 10 Hz ERD was found, starting about 2 s prior to movement onset and continuing during movement. Along with this 10 Hz ERD a localized and short-lasting (about 0.5 s) burst of 40 Hz oscillations was embedded around movement onset. This can be interpreted as indicating that planning of movement is accompanied by a desynchronization of central mu rhythm and a generation of 40 Hz oscillations.