Major white matter tracts of the cerebral hemisphere. This perspective with the cortex removed reveals the underlying white matter tracts of the cerebrum. Deep to the insula is the claustrum, which carries information between the thalamus and the basal ganglia. The external capsule is just medial to the claustrum and carries numerous corticocortical association fibers, including the inferior fronto-occipital fasciculus (IFOF) and the uncinate fasciculus. The uncinate fasciculus connects the lateral orbitofrontal cortex with the limbic system’s hippocampus and amygdala. The inferior fronto-occipital fasciculus (IFOF) is the longest bundle of association fibers in the brain and connects the parietal, posterior temporal, and occipital cortices to the frontal lobe via the external capsule. The putamen lies immediately medial to the external capsule, and is the deep nucleus separating the external capsule from the internal capsule. The major occipitotemporal association tract, the inferior longitudinal fasciculus, is visible here. (Image courtesy of AL Rhoton, Jr.)