In terms of gender effects, the 3-way interaction gender × condition × region interaction revealed that males displayed significantly higher P3 amplitude than females only at the parietal region during the gain condition. Significant gender × age group interaction indicated that males showed higher P3 amplitude than females only in the younger age group. Gender x region effect showed that overall P3 amplitudes were higher for males (than females) in central, parietal, and occipital regions, while the frontal region showed the opposite pattern (females > males). Comparison between males and females across other factors (see Fig. 4, panels B1–B2) revealed that males displayed higher P3 amplitudes (with significant differences mainly among younger subjects) than females in all but the older HR subgroup.
