Biological Psychology 51 (2000) 87 – 107 ERP components on reaction errors and their functional significance: a tutorial Michael Falkenstein *, Jo ¨ rg Hoormann, Stefan Christ, Joachim Hohnsbein Institut fu ¨r Arbeitsphysiologie an der Uniersita ¨t Dortmund (IfADo), Abt. fu ¨r Sinnes - und Neurophysiologie, Ardeystr. 67, D-44139 Dortmund, Germany Abstract Some years ago we described a negative (Ne) and a later positive (Pe) deflection in the event-related brain potentials (ERPs) of incorrect choice reactions [Falkenstein, M., Hohns- bein, J., Hoormann, J., Blanke, L., 1990. In: Brunia, C.H.M., Gaillard, A.W.K., Kok, A. (Eds.), Psychophysiological Brain Research. Tilburg Univesity Press, Tilburg, pp. 192 – 195. Falkenstein, M., Hohnsbein, J., Hoormann, J., 1991. Electroencephalography and Clinical Neurophysiology, 78, 447 – 455]. Originally we assumed the Ne to represent a correlate of error detection in the sense of a mismatch signal when representations of the actual response and the required response are compared. This hypothesis was supported by the results of a variety of experiments from our own laboratory and that of Coles [Gehring, W.J., Goss, B., Coles, M.G.H., Meyer, D.E., Donchin, E., 1993. Psychological Science 4, 385 – 390. Bern- stein, P.S., Scheffers, M.K., Coles, M.G.H., 1995. Journal of Experimental Psychology: Human Perception and Performance 21, 1312 – 1322. Scheffers, M.K., Coles, M.G.H., Bernstein, P., Gehring, W.J., Donchin, E., 1996. Psychophysiology 33, 42 – 54]. However, new data from our laboratory and that of Vidal et al. [Vidal, F., Hasbroucq, T., Bonnet, M., 1999. Biological Psychology, 2000] revealed a small negativity similar to the Ne also after correct responses. Since the above mentioned comparison process is also required after correct responses it is conceivable that the Ne reflects this comparison process itself rather than its outcome. As to the Pe, our results suggest that this is a further error-specific component, which is independent of the Ne, and hence associated with a later aspect of error processing or post-error processing. Our new results with different age groups argue against www.elsevier.com/locate/biopsycho * Corresponding author. Tel.: +49-231-1084277; fax: +49-231-1084401. E-mail address: falkenstein@arb-phys.uni-dortmund.de (M. Falkenstein) 0301-0511/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved. PII:S0301-0511(99)00031-9