Attentional Precursors of Errors Predict Error-Related Brain Activity.

The error negativity or error-related negativity (Ne/ERN), a correlate of errors in choice tasks, is related to posterror adjustments indicating that it signals the need for behavioral adjustments following errors. However, little is known about how the error monitoring system selects appropriate posterror adjustments for a given error to ensure that future errors are effectively prevented. This could be achieved by monitoring error precursors indicating potential error sources and then scaling the Ne/ERN according to the strength of the error precursor upon error occurrence. We isolated such an error precursor in alpha oscillations and tested whether it predicts the size of the Ne/ERN. A total of 28 participants (23 female, 5 male) had to classify a target in one hemifield but ignore a distractor in the opposite hemifield. Because responding to the distractor always led to an error, misallocating spatial attention to the distractor as reflected in posterior alpha was a viable error precursor in this paradigm. We found that an alpha asymmetry reversal indicated a shift of spatial attention to the distractor on error trials and predicted the Ne/ERN on a single-trial level. The Ne/ERN in turn predicted alpha asymmetry on the next trial indicating a shift of spatial attention away from the distractor. This is consistent with the idea that the error monitoring system scales the Ne/ERN according to the strength of error precursors to select appropriate posterror adjustments of behavior.