How does error correction differ from error signaling? An event-related potential study

It has been a question of debate whether immediate error corrections in speeded forced-choice reaction time tasks require an error detection signal from the performance monitoring system or whether they reflect delayed correct responses that are executed after the premature error like in a horserace. In contrast, signaling the error by pressing a response button that is unrelated to the primary task is based on error detection. The present study investigates the similarities and differences between immediate error corrections and signaling responses by means of behavioral and event-related potential data. In a within-subject design, participants performed two sessions of the flanker task. In one session, errors had to be corrected by immediately pressing the correct response, in the other session, errors had to be signaled by pressing an error signaling button. Compared to the signaling session, in the correction session, more errors and error corrections were made, reaction times were shorter, and the amplitude of the error-related negativity (ERN) was reduced. Whereas the error significance did not seem to differ across session, participants have most likely reduced the motor threshold in the correction session to enable efficient immediate corrections. This interpretation is supported by the lateralized readiness potentials and is consistent with the response conflict monitoring hypothesis of the ERN. The present study demonstrates that differences in error corrections may be attributable to differences in motor threshold. We conclude that the error signaling procedure is a more direct and reliable way to behaviorally test the functional integrity of the performance monitoring system than the instruction to correct errors. The consequences for studies in patients and with pharmacological challenges are discussed. (c) 2006 Elsevier B.V. All rights reserved.