prefrontal cortex

Meaning: The prefrontal cortex is the most anterior part of the frontal lobe, in front of the motor and premotor areas. It supports executive functions: planning, decision making, working memory, attention control, judgment, and inhibiting impulses. It is richly connected to the limbic system, so it can regulate emotional responses generated by structures such as the amygdala. It matures late in development, continuing into early adulthood, which textbooks use to explain adolescent risk taking.

On the MCAT: Passages describe a patient or animal with frontal damage, or imaging that shows activation during a planning or decision task. Phineas Gage, who survived an iron rod through the frontal lobe and then showed marked personality change and poor impulse control, is the classic case. Expect to predict deficits in planning, disinhibited or socially inappropriate behavior, and altered emotion, while basic movement and sensation are often largely intact. You may also see reduced prefrontal activity paired with heightened amygdala responses in impulsive or aggressive behavior.

Common confusion: Students treat the prefrontal cortex as the whole frontal lobe or as the motor area. The primary motor cortex lies in the precentral gyrus, and Broca's area (speech production) is also in the frontal lobe. The prefrontal cortex handles higher-order control, and it works in networks with other regions rather than alone.