For targets, factor 560 corresponded to a large, focal mid-frontal sink accompanied by off-midline centroparietal sources (Figure 5, row 6), which were analyzed by two separate ANOVA employing only site Fz or three homologous pairs over the centroparietal region (C3/4, CP5/6, P3/4). The only significant effect that emerged from these analyses was a response mode main effect for the centroparietal source, which was due to greater amplitudes for button press (for right press, 0.88 ±1.22; for left press, 1.02 ±1.25) compared with silent count (0.44 ±0.81; simple contrasts, left/right press vs. silent count, both F[1,44] ≥ 12.2, both p ≤ .0001), and also greater amplitude for left than right button press (F[1,44] = 4.23, p = .05; Figure 6).
