This area is involved in making decisions, and thus directing appropriate actions. Also, this brain area is part of the brain's reward system. This system ensures that some actions are performed more often than others.

Function
The orbitofrontal cortex is involved in planning, reasoning and making decisions. Most likely, the orbitofrontal cortex (OFC) does this by combining information from different senses. This combined package is evaluated, and possible actions are thought of. Of these, the best one is selected by looking at possible consequences (rewards and punishments) of the behavior. The action that provides the most reward will be selected by the OFC to perform.

Location
The orbitofrontal cortex is found in the middle part of the surface at the bottom of the frontal cortex. This area lies directly behind the eye sockets. Next to the area are BA 10, BA 47 and BA 45. Much input from the OFC comes from the thalamus.

Fact
This area is also often associated with addictions and compulsive behaviors. This is because the OFC helps to release dopamine in the brain. Dopamine is a substance that has a rewarding effect. When a lot of dopamine is released during a certain action, it is likely that this action will be performed again. Repeating some actions can get out of control, and the brain then wants so much dopamine that it is very difficult to inhibit yourself from performing this particular action.

Patients

There are several tests by which you can identify patients with damage to this area:

1. Subjects are taught to press a button when picture A appears (they are rewarded for this) and not to press when picture B appears (they are punished for this). After a while, the task changes, requiring people to press at image B and not press at image A. People with damage to this area cannot erase the first rule, and thus continue to press at image A. Remarkably, the patients can express the rule in words (i.e., they know it, but cannot execute it).
2. There are four piles of cards on the table. When a card is drawn, a profit or loss is made on a total amount of money. The goal of the game is to collect as much money as possible. There are two stacks that contain more 'loss' cards than 'gain' cards, it is up to the subjects to notice this during the game. With damage to the orbitofrontal cortex, subjects continue to grab from all four stacks, knowing which two stacks will cause loss, but still perform this ‘risk taking behavior’. 

Author: Myrthe Princen (translated by Joyce Burger)
Image: Marcel Loeffen