The P3 differences between age groups (Fig. 4, panels C1 and C2) are worth elaborating. It was observed that younger (12–15 years) subjects showed significantly higher P3 amplitudes in the posterior regions than their older (16–25 years) counterparts. Further, a reverse pattern (i.e., older > younger) was observed in the frontal region, although the posterior differences were more robust than the frontal differences. The finding of larger P3 in children (compared to adolescents/young adults) is in keeping with well-known developmental findings of P3 and EEG. For example, the amplitude of visual P3 decreased gradually from childhood to adulthood (e.g., Johnson, 1989; Courehesne, 1990), and this amplitude reduction can also be explained by the findings from other developmental studies which found a gradual reduction of slower rhythms (which constitute P3 response) in children’s EEG during development as they mature into adolescence/adulthood (Matousek and Petersen, 1973a; John et al., 1980; Gasser et al., 1988b; Wackermann and Matousek, 1998; Dustman et al., 1999; Clarke et al., 2001; Boord et al., 2007). In a developmental study of error-related negativity (ERN), a related component to
