Monitoring of internal and external error signals

In the present study, a modified version of the Eriksen Flanker Task has been used to study event-related potentials (ERPs) elicited by correct responses, response errors, and invalid negative response feedback following correct button presses (PC-error trials). Conventional error potentials (error related negativity [ERN/Ne]; error-positivity [Pe]) were observed after incorrect button presses but not following negative response feedback in PC-error trials. Furthermore, a late positive deflection occurred specifically after PC-errors (Late positivity [PL]), which might reflect a conscious processing of these unexpected events. The results imply some restrictions for the notion that the ERN/Ne reflects the activity of a general and generic neural error-detection system in the human brain. Furthermore, the existence of an event-detection system is indicated, which might be involved in the processing of events that violate learned expectations.