White matter tracts surrounding the lateral ventricles. Dissected in this image are portions of the visual pathways. The lateral geniculate body of the thalamus receives afferent information from the optic tracts, and provides efferent information to the occipital cortex via the optic radiations. Fibers containing information from the inferior retinal quadrants emanate from the lateral geniculate body as “Meyer’s loop” by looping anteriorly, then posteriorly, around the temporal horn of the lateral ventricle to terminate in the lingual gyrus. The remaining optic radiations course superiorly over the temporal horn. The tapetum of the corpus callosum consists of decussating fibers from the splenium of the corpus callosum that arch over the atrium of the lateral ventricle. (Image courtesy of AL Rhoton, Jr.)