data, accounting for a total of 93.6% of the variance in the data. PC1 and PC3 were maximal between 600 and 800 ms, and PC2 occurred during the N2-P3 components (~250 to 450 ms). PC2 (Delta) was chosen for further analysis for the following reasons: 1) it showed the largest no-go minus go difference (Wilcoxon Signed-Rank tests comparing activity in no-go vs. go trials: Zs = 6.455, 6.532, and 2.993, ps < 0.001, < 0.001, and = 0.003 for PCs 1–3, respectively), and occurred closest in time to the N2-P3 complex (PCs 1 and 3 represented post-P3 activity). Theta and delta were quantified as the average of six fronto-central and central sites, respectively, that were most topographically proximal to the center of the no-go minus go difference, and these averages were used as the unit of analysis (see Figure 1).
