Suppression of cerebral evoked potentials preceding rapid reaction movement.

In this study we examined the gating of the cerebral evoked potentials during warning-imperative stimulus intervals and preceding the rapid movement. We also examined the possibility of the gating phenomenon occurring in the precentral cortex. The experiment showed that the amplitudes of cerebral evoked potentials increase at all C3 and CZ during the warning-imperative stimulus intervals. Therefore, it seems that gating does not occur within the central nervous system during warning-imperative stimulus intervals. Furthermore, we observed that preceding rapid movement, the amplitudes of the cerebral evoked potentials decreased at all C3 and CZ. In the present experiment, it does not seem that a peripheral mechanism plays a role in the rapid movement. Therefore, it can be concluded that the decrease in amplitude of the cerebral evoked potentials preceding rapid movement may be due to a central mechanism irrespective of afferent information. In addition, we confirmed that the amplitude of cerebral evoked potentials decreases considerably at the precentral cortex and that the attenuation in amplitude of cerebral evoked potentials is more pronounced over the CZ than over the C3.