Longer term test-retest reliability of error-related brain activity.

The error-related negativity (ERN) is a negative deflection in the event-related potential (ERP) following an erroneous response and is thought to reflect activity of the anterior cingulate cortex. There is accumulating evidence that the component has trait-like properties; prior evidence further suggests test-retest reliability estimates ranging from .40 to .82 over a period of 2 to 6 weeks. The present study examined temporal stability over a longer time period. Error-related brain activity was recorded from 26 subjects during an arrow version of the flankers task on two occasions separated by 1.5 to 2.5 years. Depending on the scoring method, test-retest reliability of the ERN ranged from .56 to .67. These data are consistent with previous suggestions that the ERN is a moderately stable, trait-like neural measure.