Published online by Cambridge University Press: 11 September 2009
Ideas about the prefrontal cortex have changed drastically during the past century. Situated at the rostral pole of the brain, the prefrontal cortex was traditionally considered to be the seat of intelligence. Damage to the prefrontal cortex, however, does not affect overall intelligence in humans, but has detrimental effects on executive function. Converging lines of evidence indicate that the prefrontal cortex is an action-oriented region, guiding behavior by selecting relevant signals to accomplish the task at hand.
The prefrontal cortex is in a strategic position to exercise executive control. It receives information from most other cortical areas and subcortical structures and is connected with specialized oculomotor centers for searching the environment, and with motor control systems for action. These functions have been associated with the caudal parts of the lateral prefrontal cortex, namely areas 8 and the caudal part of area 46. These caudal lateral areas are connected with neighboring premotor as well as early-processing sensory association areas and with intraparietal visuomotor areas. However, the lateral prefrontal cortex is considerably more extensive, and includes, in addition, the more anteriorly situated areas around the principal sulcus (rostral area 46), area 9 on the dorsolateral surface, area 12 on the ventrolateral surface, and area 10 at the frontal pole, all of which have been associated with cognitive functions and executive control. Figure 2.1B shows the lateral prefrontal cortex and its relationship to the adjacent premotor/motor cortical system.