Know your brain: Prefrontal cortex

Where is the prefrontal cortex?

Prefrontal cortex (in yellow).

The prefrontal cortex is the section of the frontal cortex that lies at the very front of the brain.

What is the prefrontal cortex and what does it do?

Neuroscientists are beginning to recognize that it is somewhat futile to try to describe the roles of a fairly large region of cortex in just a few functions. However, it is still frequently done for the sake of simplicity. Using this approach, we can say that the prefrontal cortex is the center of executive functions in the brain.

Executive function describes the activity of a system that manages other cognitive systems, in much the way an executive of a company would. In this sense, the prefrontal cortex is involved in managing complex processes like reason, logic, problem solving, planning, and memory. It is thought that, through the integration of these multiple processes, the prefrontal cortex plays a significant part in directing attention, developing and pursuing goals, and inhibiting counterproductive impulses.

 Phineas Gage holding the rod/tamping iron that was blasted through his skull and brain.

Phineas Gage holding the rod/tamping iron that was blasted through his skull and brain.

It has also been suggested that the prefrontal cortex plays an important role in determining our personality. The oft-cited historical example to support this hypothesis is the case of Phineas Gage. The details of Gage's case are now somewhat disputed, but the part known to be true is that Gage was a railroad foreman in the mid-1800s who somehow survived having a metal rod shot clear through his skull and brain during an accident that occurred while blasting rock. Much of Gage's left frontal lobe and prefrontal cortex were destroyed. It has been suggested--although these are the points of the story that are now debated--that Gage was a responsible, hard-working man before his accident and afterwards he became a capricious, trouble-making drifter. The exact changes in Gage's personality are questionable, but there is other evidence that suggests the prefrontal cortex is important in inhibiting impulses and allowing us to exhibit proper social behavior.

A region like the prefrontal cortex that has such dense interconnections to other areas of the brain has many functions (some known and some not yet known) beyond what I've mentioned here. Many would argue, however, that the prefrontal cortex contributes more than any other part of the brain to making us who we are as individuals. According to this perspective, if you took away our prefrontal cortex we would be ruled by our desires and impulses, lacking an ability to plan for the future or think about the consequences of our actions.