What is Prefrontal cortex?
The prefrontal cortex (PFC) is the anterior portion of the frontal lobes, responsible for executive functions including planning, decision-making, working memory, impulse control, and social behavior. It is the brain region most associated with what makes humans distinct.
How it works
The PFC is the largest and most recently evolved cortical region, constituting about 30% of the human cortex (compared to 17% in chimpanzees and 7% in dogs). It is subdivided into functionally distinct regions: dorsolateral (working memory, planning), ventromedial (value-based decisions, emotion regulation), orbitofrontal (reward learning, flexible updating), and anterior cingulate (error detection, conflict monitoring). The PFC is the last brain region to fully develop (mid-20s) and the first to be impaired by stress, fatigue, and intoxication.
Applied example
The observation that the PFC is impaired by sleep deprivation, alcohol, and stress explains why self-control failures are predictable: they occur precisely when the brain region responsible for overriding impulses is functioning at reduced capacity.
Why it matters
The prefrontal cortex is the biological seat of human rationality and self-control, and understanding its limitations explains why behavior change is hardest precisely when it is most needed.
