Teenagers have a reputation for making impulsive decisions coupled with their stereotypical rebellious streak, but it may not be their fault. Researchers from the University of Iowa decided to take a look inside the brain of a teenager to find out if there were chemical differences and published their findings in the journal Psychological Science.

"The rewards have a strong, perceptional draw and are more enticing to the teenager," said the study’s coauthor Jatin Vaidya, a professor of psychiatry at the University of Iowa, in a press release. "Even when a behavior is no longer in a teenager's best interest to continue, they will because the effect of the reward is still there and lasts much longer in adolescents than in adults." Vaidya also added that the reward trait in the human brain is much more primitive than an adult’s developed decision-making process.

"I'm not saying they shouldn't be allowed access to technology," Vaidya said. "But they need help in regulating their attention so they can develop those impulse-control skills. We wanted to try to understand the brain's reward system and how it changes from childhood to adulthood. We've been trying to understand the reward process in adolescence and whether there is more to adolescent behavior than an under-developed frontal lobe.”

Researchers examined 40 adolescents, ages 13 and 16, and compared them to 40 adult brains of 20 and 35 year olds. Participants were asked to find a red or green ring hidden among an array of various ring colors on the computer screen, and were given a monetary reward for finding a specific colored ring and reporting whether or not there was a vertical or horizontal line inside the rings. After 240 trials, the researchers gave them the new target of a diamond, the differences between the adults and adolescents became clear.

"Even though you've told them, 'You have a new target,' the adolescents can't get rid of the association they learned before," said the study’s coauthor Shaun Vecera, a professor of psychology at the University of Iowa, in the press release. "It's as if that association is much more potent for the adolescent than for the adult. If you give the adolescent a reward, it will persist longer. The fact that the reward is gone doesn't matter. They will act as if the reward is still there."

The adolescents kept choosing the rings despite the new instructions because they were geared towards seeking out the monetary reward. There was no monetary award associated with the diamond, which made it less appealing to their underdeveloped brain’s restraint. Researchers believe the teenagers inability to adjust their behavior may explain why they’ll continue to make inappropriate jokes long after their friends stopped laughing. Their next experiment aims to look at the neurological affects of their ring-versus-diamond trial with teenagers and adults in order to see what brain regions are being engaged and disengaged during the activity.

"Are there certain brain regions or circuits that continue to develop from adolescence to adulthood that play [a] role in directing attention away from reward stimuli that are not task relevant?" Vaidya asked. "Also, what sort of life experiences and skill help to improve performance on this task?"

Source: Vaidya JG, Vecera SP, and Roper ZJJ. Value-Driven Attention Capture in Adolescence. Psychological Science. 2014.