The Adolescent Brain and Decision Making Skills
Limbic System & Prefrontal Cortex Development in the Teen Years
Oct 29, 2009
The brain’s cortex has received plenty of attention from scientists lately when studying the emotional development of the adolescent brain. Through brain imaging MRI scans, researchers continue to study changes in the prefrontal region of the cortex during the teen years. Now neuroscientists are also looking at the brain’s limbic system and it’s role in decision making skills and risk taking behavior during adolescence.
What is the Prefrontal Cortex?
The cortex is the outer layer of the brain, the section under the rippled surface that most people think when they think of the shape of the brain. The prefrontal cortex is the section of the cortex that is in the front of the brain, behind the forehead. The prefrontal lobe of the cortex is responsible for high level thinking tasks such as problem solving, reasoning and complex decision making skills. Scientists used to think that the prefrontal region of the cortex matured earlier than the teen years, but have discovered that it develops throughout adolescence until the early 20’s.
Decision Making in the Adolescent Brain
Teenagers are known for being impulsive, taking risks and having emotional outbursts. Neuroscientists aren’t certain about all of the variables responsible for high risk taking and aggressive behaviors during the teen years, but two brain functions appear to be significant in decision making for the adolescent brain – the activity in the prefrontal cortex and the limbic system.
The Prefrontal Cortex and Decision Making
After the discovery that the frontal lobe of the cortex is not fully developed in the adolescent brain, scientists began speculating cause and effect. Could the lack of maturity of the cortex be the reason for poor decisions and unhealthy risk taking during the teen years? But after looking at teen behavior, scientists pointed out that teens are often making poorer decisions than children half a teen’s age. Scientists then began to look to the limbic system of the brain for clues about the risk taking, emotionally sensitive adolescent brain.
The Limbic System and Decision Making
The limbic system plays a big role in recognizing emotions and linking those emotions to various brain functions. It recognizes pleasure and pain associated with memories from the past and motivations for the present. Nearly 100% developed by the teen years, the limbic system maintains a state of hyperawareness in the adolescent brain.
In 2008, B. J. Casey’s research team at Weill Medical College of Cornell University and California Institute of Technology published an article suggesting that the limbic system is the major contributor of poor judgment and impulsivity in the teen brain. The team proposed that although the frontal lobe of the cortex can weigh options to make a decision with a safe outcome, a teen’s “on guard” limbic system often wins out over the reasoning of the prefrontal cortex resulting in more high risking taking decisions. The theory is that the impulsive ever vigilant limbic system keeps a teen’s brain focused on primal tasks such as finding a mate, elevating one’s status with peers and seeking pleasure activities such as eating, sex and novelty.
Parents of teens know first hand how quick to anger and easily provoked their children can be during the teen years. As parents try to make sense of a teen’s nonsensical behavior, they may want to remember that the quick deciding, risk taking limbic system often overrides the rational decisions of the slower reasoning prefrontal cortex.
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