The effects of response parameters on CNV amplitude

The contingent negative variation (CNV) was recorded using an inter-stimulus interval of 4 sec in the context of variations in the parameters of button press responses to be performed following S2. The response parameters manipulated were response duration, the number of fingers used, the number of discrete movements and the complexity of response sequences. The CNVs were averaged with reference to both the stimuli and the response. Variations in response parameters were apparent only in measures of response averaged CNVs. Negativity following response onset was also related to response parameters, again only for response-locked averages. These results support the contention that the CNV, like the Bereitschaftspotential (BP), is primarily related to response factors, and hence that the CNV and the BP are essentially the same phenomenon. It is suggested that the results indicate that negativity prior to, and possibly following, response onset represents the formulation of response-specific motor programs.