Dramatic Changes in the Brain Explain Teenage Risk Taking

Teenage exploration and risk taking could be explained by dramatic changes in the brain that allow elaborate planning, according to new research.

A neuroscientist at the University of Pittsburgh School of Medicine also found that teenage brains are driven by the need for immediate rewards.

“Our studies are beginning to challenge the traditional concept that the teenage brain can’t plan because of an immature prefrontal cortex,” said Beatriz Luna, Ph.D., a professor of psychiatry and pediatrics.

“Our findings indicate that the teen prefrontal cortex is not much different than in the adult, but it can be easily overruled by heightened motivation centers in the brain. You have this mixture of newly gained executive control, plus extra reward, that is pulling the teenager toward immediate gratification.”

Using a model in which eye movements, or saccades, reveal insight into executive brain function, Luna studied hundreds of young volunteers to examine brain development during the transition between childhood and adulthood.

In these experiments, volunteers are instructed to immediately look away from a small light that randomly appears on a screen in front of them. This “anti-saccade” test shows if the brain is able to engage the planning centers of the prefrontal cortex to overcome the impulse to look toward the light rather than away from it, the researcher explained.

Luna’s research team found in previous studies that children succeed in about half their tries, teens in about 70 percent of tries, and adults in about 90 percent of tries. People with mental illnesses typically struggle with the task, she noted.

The researchers had volunteers do the experiment while scanning their brains with functional MRI. They found that much of the architecture of the mature brain is in place by adolescence, but the ability of the networks to talk to one another and integrate information is still a work in progress.

“Further enhancement of this network integration is likely why adults can switch and very quickly adapt their behavior to changing circumstances, which is more difficult for adolescents,” Luna explained.

She added that while parents and teachers sometimes find the choices teens make bewildering, their brains are perfectly adapted to explore and take more chances as they become independent adults.

“Across societies and species, we know that adolescence is a period of increased sensation seeking that can lead to risk taking, which increases mortality rate,” Luna said.

“Also, we often see during this period the first signs of mental illnesses, such as schizophrenia, depression and eating disorders. All of these have a neurobiological basis, so if we know how the brain is changing, we might be able to figure out a way to intervene earlier in life.”

Source: University of Pittsburgh School of Medicine