integrating the distance between consecutive points on each of the tractography-defined visual callosal fibers, and averaging over all fibers. Mean curvature for each fiber was calculated by integrating the inverse of the radius of the osculating circle along the fiber and dividing by the fiber length. Average curvature for the entire bundle was then calculated by averaging the mean curvature of each fiber. Adding these variables did not significantly augment the amount of variance accounted for by the model (R2-change = 0.008, F2,29=.168, p=.846), and the revised model remained significant when these variables were included (F4,33=3.036, p=.033), indicating that the observed association between IHTT and FA/Mode was not being driven by within-subject variations in fiber length or fiber curvature.
