The primate brain connectivity bauplan and human-specific variations

The organization of connectivity in human brains follows a general primate connectivity ‘bauplan.’ Variations specific to the human lineage are mostly found in association fibers. Parietal-frontal connectivity is much more elaborate than seen in other primates, and this is related to the expansion of both these parts of association cortex. Temporal cortex specializations are often underappreciated, but quite prominent. Dorsal longitudinal fibers project deep into temporal cortex and ventral temporal longitudinal tracts have prominent parietal projections. These anatomical specializations are thought to relate to particular behavioral domains, including social cognition and language.