In the largest study in adolescents thus far, Schmithorst et al measured anisotropy and diffusivity in a group of typically developing subjects (104, 52 male, mean age 12.3 +- 3.5 years)(Schmithorst et al., 2008). They found higher FA and lower mean diffusivity in females in the splenium of the corpus callosum, while in males, FA was higher and mean diffusivity was lower in bilateral frontal WM regions, the right arcuate fasciculus, and left parietal and parieto-occipital WM. Correlations of FA with age also differed between brain regions in males and females; for example, left frontal lobe FA was positively correlated with age in boys, but negatively correlated with age in girls.
