Figure 4 illustrates the least-square mean values of N2 peak amplitudes for both groups. As seen in the figure, controls produced larger mean peak N2 amplitudes than alcoholics at all regions. Further, NoGo N2 mean amplitudes were largest at the frontal regions and Go N2 mean amplitudes were largest at the central regions in both groups. The mean NoGo N2 amplitude at frontal regions was the largest (m = -5.71) in controls whereas mean Go N2 amplitude at central region was the largest (m = -4.46) in alcoholic subjects.
