Chapter 35: the frontal lobes

The frontal lobes occupy an exalted position in neuroscience. The largest and most recently evolved of the cerebrum's four lobes, these regions have long been regarded as harboring unique capacities most specific to the human mind. Understanding has been steadily developed, but a unitary function that captures the role of the frontal lobes has proven elusive. In antiquity, Hippocrates and Galen speculated that mental activities were located in the brain, and in the Renaissance, Leonardo and Vesalius made important advances in brain neuroanatomy. The 17th century witnessed Willis recognizing frontal brain regions, and in the 18th, Swedenborg first associated these areas with intellect. Defined neuroanatomically by Chaussier in 1807, the frontal lobes were soon assigned higher faculties by Gall and Spurzheim, and later, the case of Phineas Gage and the work of Broca clarified comportmental and linguistic dimensions of frontal lobe function. In the 20th century, progress came with Luria's observations of frontal lobe injuries and from the psychosurgery era, followed by contributions of behavioral neurology, neuroimaging, and neuroanatomy, which helped delineate frontal regions, circuits, and networks relevant to specific cognitive and emotional operations. Today, a host of important societal implications merit attention as neuroscientific investigation continues to enrich knowledge of the frontal lobes by identifying the basis of singular human behaviors.