The prefrontal cortex Biological Level of AnalysisDoryane Lemeunier

Content:

• A simple description of the location within the brain

• A general overview of the functions of the part of the brain

• Three studies involved with this part of the brain

• What happens when this part of the brain is dysfunctional?

A simple description of the location within the brain

• A human brain. The prefrontal cortex is located in the front part of the red section, which is the frontal lobe.

Extra info:

Yellow: parietal lobe

Blue: temporal lobe

Green: occipital lobe

Purple: Cerebellum

A general overview of the functions of the part of the brain

• regulates thoughts in terms of both short-term and long-term decision making.

• It allows to create strategies

• to adjust actions or reactions in changing situations

• allows humans to consider several different yet related lines of thinking when learning or evaluating complex concepts or tasks.

• controls intense emotions and impulses

• inhibits inappropriate behaviors hence encourages wise, acceptable choices

• allow humans to balance immediate reward with long-term goals

Prefrontal Cortex is aka Seat of good judgment

What happens when this part of the brain is dysfunctional?

• There is much current research devoted to understanding the role of the prefrontal cortex in neurological disorders. Many disorders, such as 

o schizophrenia, 

o bipolar disorder,

o ADHD,

• have been related to dysfunction of the prefrontal cortex, and thus this area of the brain offers the potential for new treatments of these conditions (citation needed). Clinical trials have begun on certain drugs that have been shown to improve prefrontal cortex function, including  guanfacine, which acts through the alpha-2A adrenergic receptor. A downstream target of this drug, the HCN channel, is one of the most recent areas of exploration in prefrontal cortex pharmacology.

Here’s an interesting video

First study involved with this part of the brain

• Shiv was curious whether “cognitive load” could influence self-control, so he gave half of the subjects a two-digit number to memorize (low load), while the other half were given a seven-digit number (high load). Subjects were then instructed to walk to another room in the building. On the way they passed by a table at which they were presented with a choice between a caloric slice of chocolate cake or a bowl of fruit salad. Fifty-nine percent of the people trying to remember seven digits (high load) chose the cake, while sixty-three percent of the two-digit subjects (low load) chose the fruit salad. In other words, having people memorize an extra five digits made them exhibit significantly less self-control.

WHY?

• Why did the number of digits have such a strong effect? Shiv speculates that the effort required to memorize seven numbers drew cognitive resources away from our ability to control our urges. This makes anatomical sense, since working memory and self-control are both located in our prefrontal cortex. Having to remember seven numbers occupied neurons that would otherwise help us decide what to eat, which causes us to become more reliant on our impulsive emotions. While we tend to think of self-control as being an innate trait, it is actually dependent on a range of extrinsic factors, all of which affect the way our brain responds to a given situation.

Second and third study involved with this part of the brain

• Investigating the role of the prefrontal cortex in conscious monitoring

http://mtl.fonoaud.utalca.cl/docs/work_papers/slachevsky.pdf

• Bump attractor dynamics in prefrontal cortex explains behavioral precision in spatial working memory

http://www.nature.com/neuro/journal/v17/n3/full/nn.3645.html