Error Monitoring: Feedback-Driven Modulation of the ERN in Partial Inhibitions

The error-related negativity (ERN) is a prominent electrophysiological response that immediately follows an incorrect response. It is thought to reflect an error detection mechanism. Much of the ERN literature classifies responses binarily: correct or incorrect, making it unclear how the ERN is affected when an incorrect response is stopped before completion (partial inhibition). This research aimed to examine whether ERN amplitude is sensitive to graded motor output during partial inhibitions, and whether external feedback modulates ERN responses in this context. In Experiment 1, an anticipatory stop-signal timing task was used, and participants received negative feedback on their motor response (told their response was incorrect) when they partially inhibited them. In contrast, in Experiment 2, participants received positive feedback (told they were correct) when they partially inhibited their responses. We found that negative feedback did not modulate the ERN amplitude, but positive feedback did. The ERN response differed between partial and unsuccessful inhibitions. An explanation for this could be an expectancy violation: positive feedback was incongruent with the participant's judgement of their performance. Therefore, participants were likely surprised by the feedback they received, highlighting that the error-monitoring system is influenced by the cognitive interpretation of actions within a given feedback context, while we found no evidence that ERN amplitude scaled with response force. Keywords: error-monitoring, partial inhibition, error-related negativity.