An ANOVA of P3 amplitude at medial–lateral sites over each hemisphere showed the same Group difference as seen for the midline sites (F = 5.37, df = 1,38, P = 0.026), but there was no interaction involving Group and Hemisphere, which indicates that the smaller P3 in patients was not dependent on hemisphere. There was a significant main effect of Hemisphere (F = 5.71, df = 1,38, P = 0.022) and a Hemisphere by Condition by Site interaction (F = 9.36, df = 6,228, P<0.001). Analyses of simple effects indicated that this interaction reflected larger P3 amplitude over right than left hemisphere at only central and parietal sites for targets and novels (Hemisphere by Site interaction: for targets, F = 15.56, df = 3,114, P<0.001, ε = 0.76; and novels, F = 4.08, df = 3,114, P = 0.015, ε = 0.80).
