Recent work shows that both ERN and Pe amplitudes stabilize after around six error trials (Hajcak & Simons, 2008; Olvet & Hajcak, 2009). Thus, only participants who committed at least six errors were included in the ERN and Pe analyses (three placebo participants and one alcohol participant were excluded). Figure 4 displays response-locked ERP waveforms for error trials (upper panel) and correct trials (lower panel) as a function of beverage group.
