Your teen's brain behind the wheel explained

By RELAXNEWS | 24 April 2015

CHICAGO: Adolescent brains negotiate risk differently than those of adults and a new study exposes what modulates their risk tolerance as they drive.

Working with 14-year-old participants who were accompanied by their mothers, the research team tracked blood flow in their brains as they completed a simulated driving task.

In one experiment, teens drove alone and in the other, their mothers were watching, according to the study.

When driving alone, teens find risky decisions rewarding, the research revealed, but a mother's presence can nullify that thrill, potentially leading to wiser decisions.

Upon running a yellow light, blood flow increased to the reward centre of the brain, called the ventral stratum, when the teen drove alone.

This part of the brain has been demonstrated in prior studies to be more sensitive to rewards during adolescence than any other part of life.

"The prevailing view is that this peak in reward sensitivity in adolescence underlies, in part, adolescent risk-taking," says lead author Eva Telzer.

Yet with Mom watching, this effect was minimal, according to the study, and teens used the brakes considerably more upon approaching yellow lights.

"The teens go from about 55 percent risky choices to about 45 percent when their mom is watching," says Telzer. "That's a big effect."

In the presence of their mothers, the teens' prefrontal cortex activated when they hit the brakes, yet this did not happen when they hit the brakes while driving alone, say the researchers.

This part of the brain is associated with cognitive control, and it's important in the art of regulating behavior, says Telzer, who says the two mechanisms of nullifying the risk reward factor and activating the prefrontal cortex have implications for road safety.

"A parent's presence is actually changing the way the adolescent is reasoning and thinking about risk -- and this increases their safe behavior," she says.

The study was published in the journal Social Cognitive and Affective Neuroscience.