Study Shows Working Memory Is Driven By Prefrontal Cortex And Dopamine
One of the unique features of the human mind is its ability re-prioritize its goals and priorities as situations change and new information arises. This happens when you cancel a planned cruise because you need the money to repair your broke-down car, or when you interrupt your morning jog because your cell phone is ringing in your pocket.
In a new study published in the Proceedings of the National Academy of Sciences (PNAS), researchers from Princeton University say that they have discovered the mechanisms that control how our brains use new information to modify our existing priorities.
The team of researchers at Princeton’s Neuroscience Institute (PNI) used functional magnetic resonance imaging (fMRI) to scan subjects and find out where and how the human brain reprioritizes goals. Unsurprisingly, they found that the shifting of goals takes place in the prefrontal cortex, a region of the brain which is known to be associated with a variety of higher-level behaviors. They also observed that the powerful neurotransmitter dopamine – also known as the “pleasure chemical” – appears to play a critical role in this process.
Using a harmless magnetic pulse, the scientists interrupted activity in the prefrontal cortex of the participants while they were playing games and found they were unable to switch to a different task in the game.
“We have found a fundamental mechanism that contributes to the brain’s ability to concentrate on one task and then flexibly switch to another task,” explained Jonathan Cohen, co-director of PNI and the university’s Robert Bendheim and Lynn Bendheim Thoman Professor in Neuroscience.
“Impairments in this system are central to many critical disorders of cognitive function such as those observed in schizophrenia and obsessive-compulsive disorder.”
Previous research had already demonstrated that when the brain uses new information to modify its goals or behaviors, this information is temporarily filed away into the brain’s working memory, a type of short-term memory storage. Until now, however, scientists have not understood the mechanisms controlling how this information is updated.
