The error-related negativity associated with different strength of stimulus–response interference

ObjectiveThe present study was aimed at clarifying the effect of stimulus–response compatibility (SRC) interference on the ERN.MethodsWe compared ERNs in two tasks differing in the level of interference, an arrow (AR) task classified as a Simon task and a more complex arrow-orientation (AO) task classified as a spatial-Stroop task. We also compared ERNs between partial errors (with initial incorrect movement corrected by a proper full response) and overt (uncorrected) errors.ResultsBehavioral response time and error rate indicated that both interference and ERN amplitude were larger for the AO task than for the AR task. There was no significant difference in the ERN amplitude between the partial and overt errors.ConclusionsThe ERN becomes larger as a function of the SRC interference.SignificanceOur study presented evidence that the ERN may represent response-monitoring associated with the SRC interference.

► The error-related negativity (ERN) elicited by both overt and partial errors became larger when the interference was stronger. ► Two different stimulus–response compatibility tasks, a spatial Stroop task and a Simon task, were compared, allowing us to systematically vary the strength of the interference effect. ► Focusing on the partial EMG that was followed by corrective EMG, it appears that the conflict-related N2 likely co-exists with the ERN in a stronger interference situation.