Impulsiveness and ERP components in a Go/Nogo task.

Impulsiveness has been linked to fast guesses and premature responses in reaction time tasks like the Eriksen flanker task or the Go/Nogo task. In the present study, healthy subjects without history of DSM-IV Axis I or II psychopathology were examined. Impulsiveness was determined by calculating individual reaction times (as a function of general response speed) in order to split the entire group (n = 26) in a subgroup with a more controlled response style (low impulsiveness [LI] group; n = 13) and a subgroup with a more impulsive response style (high impulsiveness [HI] group; n = 13). Subjects performed a Go/Nogo task while a multi-channel EEG was recorded. Two event-related potentials (ERP) were of special interest: the Nogo-N2 and -P3 component. HI subjects had significantly reduced (less positive) Nogo-P3 amplitudes compared to LI subjects whereas groups did not differ with regard to the Nogo-N2. These results corroborate previous findings of reduced Nogo-P3 amplitudes in samples with enhanced levels of impulsiveness. Moreover, present data suggest that there is a broader range of impulsiveness even in healthy subjects which might mask or pronounce between-group differences in clinical studies. Therefore, different levels of impulsiveness in control groups should be carefully taken into account in further ERP studies.