Losing the error related negativity in the EEG of human subjects: an indicator for willed action

When people make errors in a discrimination task, a negative-going waveform can be observed in scalp-recorded EEG that has been coined the error-relat ed negativity (ERN). We hypothesized that the ERN only occurs with slips, t hat is unwilled action errors, but not if an error is committed willingly a nd intentionally. We investigated the occurrence of the ERN in a choice rea ction time task that has been shown to produce an ERN and in an error simul ation task where subjects had to fake errors while the EEG was recorded. We observed a loss of the ERN when errors were committed in willed actions bu t not in unwilled actions thus supporting the idea that the production of t he ERN is tied to slips in unwilled actions but not mistakes in willed acti ons. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.