As in our prior study,48 the net effect of detecting targets by either pressing a response button or by silently counting was computed by subtracting the topography of factor 560 for silent count from the mean topography for left and right press (Figure 6, bottom row). As previously seen for the larger sample of healthy adults, this net difference revealed a relative source for the silent count condition over lateral regions of the left hemisphere, particularly for controls (cf. dark blue region at left-lateral sites in the difference topography). Another post-hoc ANOVA was therefore computed for factor 560 using two homologous pairs of lateral-temporal sites (T7/8, TP9/10). This analysis confirmed across groups the greater 560 source at temporal sites for silent count (0.04 ±0.93) versus right (−0.30 ±1.17) and left (−0.30 ±1.07) button presses (response mode main effect, F[2,88] = 9.72, p = .0004, ε = .83; simple contrasts, right/left press vs. silent count, F[1,44] ≥ 11.5, both p = .001; right vs. left press, F[1,44] < 1.0, n.s.). However, these response-related effects were substantially reduced in patients (right press,
