ERN amplitude on incompatible trials was submitted to a 3 (Group: control, placebo, alcohol) × 2 (Accuracy: correct, incorrect) × 2 (Coronal: frontal-central, central) × 3 (Sagital: left, midline, right) HLM. A main effect of Accuracy, F(1, 957) = 1099.68, p < .001, with greater amplitude on incorrect (M = −5.08 µV) than correct (M = 1.14 µV) trials, was qualified by a Group × Accuracy interaction, F(2, 957) = 3.34, p = .04. ERN amplitude was greater for incorrect trials in the placebo group (M = −5.88 µV) compared to the alcohol group (M = −4.14 µV), t(957) = 2.54, p = .01, consistent with previous work (Bartholow et al., 2012; Ridderinkhof et al., 2002). ERN amplitude was marginally greater in the control group (M = −5.20 µV) compared to the alcohol group, t(957) = 1.49, p = .13, and did not differ significantly between the control and placebo groups, t < 1, p = .34. For correct trials, amplitude was marginally greater for the placebo group (M = .93 µV) compared to the alcohol group (M = 2.09
