To determine whether the beverage effect on the post-error CE was pharmacological and not due to expectancy effects, planned contrasts were conducted comparing the alcohol group with the average of the control and placebo groups (pharmacology) and the control group with the average of the placebo and alcohol groups (expectancy). The CE following errors was significantly larger in the alcohol group (M = 67 ms, SD = 33) compared to the average of the control and placebo groups (M = 45 ms, SD = 47), t(91) = 2.35, p = .02, indicating a significant pharmacological effect. However, the control group’s post-error CE (M = 46 ms, SD = 47) did not differ reliably from the average of the placebo and alcohol groups (M = 55 ms, SD = 42), t < 1, p = .36.
