This observation was also reflected in the age-dependent differences with respect to regression variable βage of the normalized myelin content across the entire cortex. Figure 3A shows that the areas with greater gains (red) and lesser gains (blue) during adolescence (NCANDA) almost entirely disappeared during young adulthood (HCP). Furthermore, the significant vertex-wise (Figure 3B) and parcellated (Figure 3C age-dependent regions (shown in non-gray) were larger in the NCANDA adolescents than young HCP adults. During adolescence, greater gains in vertex-wise, normalized myelin content were significant (shown in red/yellow in Figure 3B) primarily in the primary motor cortex; lesser gains in the normalized myelin content (shown in blue/green) were located in the cingulate cortex, precentral sulcus, and insula cortex. Significant regional age-dependent differences (Figure 3C were observed in the primary motor cortex ([Brodmann] area 4) (Nieuwenhuys 2013) and cingulate cortex ([Vogt] areas 23c, p24', a24') (Vogt et al. 1995). Of those regions, areas 4 (left hemisphere) and p24' (right hemisphere) were also significantly different within the HCP young adults (P < 0.05) (Table 2 and Figure 4). However, with respect to areas
