Motor and Nonmotor Components of Event-Brain Potential in Preparation of Motor Response

Stimulus-preceding negativity (SPN), readiness potential (RP), and contingent negative variation (CNV) were recorded to verify the hypothesis that the CNV late wave is the sum of the RP and the SPN. SPN and RP were elicited using a time-estimation task, and the CNV was recorded using a warned reaction-time task. A “virtual CNV” was calculated by superimposing the SPN on the RP. Then the real and virtual CNVs were compared to evaluate the hypothesis. Although an amplitude difference between the real and virtual CNV late waves was observed at the frontal site, the amplitudes at the central and parietal sites were not different between the two. These results suggest that the CNV late wave and the SPN might have a common underlying physiological mechanism in the parietal area, and that these potentials might be related to attentional systems.