Average CRN and ERN amplitudes were assessed at electrode FCZ between 20 and 120 ms following the response, which is the time interval within which these potentials reached their peak. A significant effect of diagnosis was revealed for the amplitude of the CRN [F(1, 25) = 9.37; p = 0.005]; here, the alcoholic group generated larger negative amplitude potentials for all condition types (HsHr, HsLr, LsHr, and LsLr) than the control group. No main effect of stimulus complexity (p = 0.593) was observed. In contrast, an effect of response congruency [F(1, 25) = 10.48; p = 0.003) was found. No interactions between the factors were observed (p > 0.128). The results of the univariate analysis on the ERN showed a trend for an effect of diagnosis [F(1, 25) = 4.16; p = 0.052] such that alcoholics thus also developed larger negative ERN amplitudes following incorrect responses than the controls (Figs. 5, 6).
