Figure 1.

Group differences in FA and RD. a, Increased FA in bilinguals compared to monolinguals. Colored voxels (orange-red) are significant clusters (p < 0.05, corrected) in corpus callosum, extending to bilateral superior longitudinal fasciculi and right inferior frontal–occipital fasciculus, shown on a white matter skeleton (green) and overlaid onto the MNI-152 T1 brain (seen in gray). b, Increased RD in monolinguals relative to bilinguals. Colored voxels (blue) are significant clusters (p < 0.05, corrected) overlapping with part of the WM tracts identified in a).