Figure 6 shows the grand average source images (see
Fig. 6a) and the histograms of averaged source activations (see
Fig. 6b) for the target N2 component. There was a significant main effect of the defect condition in the right occipital regions (BA 17, 18, and 19; F (3, 117) = 4.364,
P = 0.006, partial η² = 0.101), indicating that the source activity of 5-degree, 10-degree, and 20-degree defects were smaller than that of 30-degree defects (5-degree < 30-degree,
P = 0.001; 10-degree < 30-degree,
P = 0.023; and 20-degree < 30-degree,
P = 0.001). There was a significant main effect of the defect condition in the right inferior temporal regions (BA 20, 21, 22, and 38; F (3, 117) = 6.238,
P = 0.001, partial η² = 0.138), indicating that the source activity of 5-degree, 10-degree, and 20-degree defects was smaller than that of 30-degree defects (5-degree < 30-degree,
P = 0.002; 10-degree < 30-degree,
P = 0.003; and 20-degree < 30-degree,
P < 0.001). There was a significant main effect of the defect condition in the right ventrolateral prefrontal regions (BA 11, 45, and 47; F (3, 117) = 6.002,
P = 0.001, partial η² = 0.133), indicating that the source activity of 5-degree, 10-degree, and 20-degree defects was smaller than that of 30-degree defects (5-degree < 30-degree,
P = 0.004; 10-degree < 30-degree,
P < 0.001; and 20-degree < 30-degree,
P = 0.002).