Two types of movement-related cortical potentials preceding wrist extension in humans.

We compared the occurrence patterns of movement-related cortical potentials (MRCPs) preceding wrist extension in athletes (kendoists and gymnasts) and non-athletes. The MRCPs of the non-athletes started approximately 1.5 s before the EMG onset of wrist extension. In the athletes, the duration of the MRCPs was shorter and the amplitudes of early component (Bereitschaftspotential) were smaller than in the non-athletes. The MRCPs in the athletes started approximately 400 ms before the onset of wrist extension and increased rapidly. In topographical maps, MRCPs of the athletes were localized markedly on the contralateral motor area (C3) compared with the non-athletes. In the present study, the duration of MRCPs was classified into two types.