Classical results

Fig. 3 depicts the ERD/ERS time courses for the 10-12, 14-18 and 36-40 Hz bands. The alpha band (mu) desynchronization (10-12 Hz) starts 2.5 s before movement-onset, reaches maximal desynchronization shortly after movement-onset and recovers to baseline level within a few seconds. The central beta activity (14-18 Hz), in contrast, displays a short-lasting ERD during initiation of movement followed by a synchronization (ERS) with a maximum after the movement execution. It is of interest that the beta ERS occurs while the mu rhythm still shows a desynchronization. The 40-Hz oscillations (36-40 Hz) reveal a sharp power increase shortly before movement-onset.

Figure 3: ERD/ERS in three bands: $\alpha$ 10-12 Hz, $\beta$ 14-18 Hz, $\gamma$ 36-40 Hz. Insert: electrode positions C3, Cz and C4 from the 10-20 system marked by thicker circles. Results presented for electrode marked by filled circle.