Abstract
In this study, ERPs and EMG were recorded in a GO/NO-GO task of discriminating between two visual stimuli. Eight right-handed subjects were required to respond to one of those stimuli (GO trial) but not to the other (NO-GO trial). The NO-GO potential relating to the function of response inhibition appeared largely at frontal and central sites in NO-GO trials. In the NO-GO trials with the error at the muscular level, the other negativity was also found overlapping with the NO-GO potential. Additional analyses were done on the EMG latency, the other negativity latency, and the wave forms triggered by the EMG response. The results suggest that the negativity, that was different from the NO-GO potential, was possibly the error-related negativity (ERN). In addition, it was suggested that there may be a trade-off relationship between the time required in an error detection processing that the ERN is thought to reflect and the accuracy of subject's response. Finally, some methodological problems in excluding the ERN overlapping the other ERPs were discussed.
