Distinct Processing of Selection and Execution Errors in Neural Signatures of Outcome Monitoring

Losing a point playing tennis may result from poor shot selection or poor stroke execution. To explore how the brain responds to these different types of errors, we examined EEG signatures of feedback-related processing while participants performed a simple decision-making task. In Experiment 1, we used a task in which unrewarded outcomes were framed as selection errors, similar to how feedback information is treated in most studies. Consistent with previous work, EEG differences between rewarded and unrewarded trials in the medial frontal negativity (MFN) correlated with behavioral adjustment. In Experiment 2, the task was modified such that unrewarded outcomes could arise from either poor execution or selection. For selection errors, the results replicated that observed in Experiment 1. However, unrewarded outcomes attributed to poor execution produced larger amplitude MFN, alongside an attenuation in activity preceding this component and a subsequent enhanced error positivity (Pe) response in posterior sites. In terms of behavioral correlates, only the degree of the early attenuation and amplitude of the Pe correlated with behavioral adjustment following execution errors relative to reward; the amplitude of the MFN did not correlate with behavioral changes related to execution errors. These results indicate the existence of distinct neural correlates of selection and execution error processing and are consistent with the hypothesis that execution errors can modulate action selection evaluation. More generally, they provide insight into how the brain responds to different classes of error that determine future action.