Six corpus callosum regions of interest (ROIs) as geometric masks, prior to being convolved with left-right segmentation maps. The regions, based on definitions from Witelson (1989) are as follows: (A) Splenium, (B) Isthmus, (C) Posterior Midbody, (D) Anterior Midbody, (E) Rostral Body, and (F) Genu. The masks are displayed on the FMRIB 58-subject average FA map. These ROI served as the seed points for the tractography.