PITTSBURGH, Feb. 14, 2015 - Teenage exploration and risk taking could be explained by dramatic changes in the brain that allow elaborate planning and are driven by the need for immediate reward, according to a University of Pittsburgh neuroscientist who will be talking about her research in a panel discussion and press briefing at the American Association for the Advancement of Science annual meeting, Feb. 13 to 16, in San Jose, Calif.
Using an elegant model in which eye movements, or saccades, reveal insight into executive brain function, Beatriz Luna, Ph.D., Staunton Professor of Psychiatry and Pediatrics, Pitt School of Medicine, has studied hundreds of young volunteers to examine brain development during the transition between childhood and adulthood.
"Our studies are beginning to challenge the traditional concept that the teenage brain can't plan because of an immature prefrontal cortex," Dr. Luna said. "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."
In the 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. Dr. Luna's team has 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.
The study team had volunteers do the same tasks while scanning their brains with functional MRI. They found that much of the architecture of 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," Dr. Luna explained.
She added that while parents and teachers sometimes find bewildering the choices teens might make, their brains are perfectly adapted to explore and take some 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," Dr. 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."
Dr. Luna and researchers from the Children's National Medical Center, Washington, D.C.; Columbia University Medical Center; and University of California, Berkeley, will present their work from 1:30 to 4:30 p.m., Saturday, Feb. 14, during a AAAS session called "From Womb to Tomb."
They also will participate in a news briefing that day which will be webcast at 10 a.m. PT, 1 p.m. ET, at http://www.eurekalert.org/aaasnewsroom/2015/.
Watch a video of Dr. Luna describing her work.
About the University of Pittsburgh School of Medicine
As one of the nation's leading academic centers for biomedical research, the University of Pittsburgh School of Medicine integrates advanced technology with basic science across a broad range of disciplines in a continuous quest to harness the power of new knowledge and improve the human condition. Driven mainly by the School of Medicine and its affiliates, Pitt has ranked among the top 10 recipients of funding from the National Institutes of Health since 1998. In rankings recently released by the National Science Foundation, Pitt ranked fifth among all American universities in total federal science and engineering research and development support.
Likewise, the School of Medicine is equally committed to advancing the quality and strength of its medical and graduate education programs, for which it is recognized as an innovative leader, and to training highly skilled, compassionate clinicians and creative scientists well-equipped to engage in world-class research. The School of Medicine is the academic partner of UPMC, which has collaborated with the University to raise the standard of medical excellence in Pittsburgh and to position health care as a driving force behind the region's economy. For more information about the School of Medicine, see http://www.medschool.pitt.edu.