The anatomy of the human frontal lobe.

Throughout evolution the frontal lobes have progressively acquired a central role in most aspects of cognition and behavior. In humans, frontal lobe functions are conditional on the development of an intricate set of short- and long-range connections that guarantee direct access to sensory information and control over regions dedicated to planning and motor execution. Here the frontal cortical anatomy and the major connections that constitute the local and extended frontal connectivity are reviewed in the context of diffusion tractography studies, contemporary models of frontal lobe functions, and clinical syndromes. A particular focus of this chapter is the use of comparative anatomy and neurodevelopmental data to address the question of how frontal networks evolved and what this signified for unique human abilities.