Good
thing we have red light cameras (too bad they don’t work)
University of Illinois at Urbana-Champaign, Science Daily
A new study of teenagers an d their moms reveals how adolescent
brains negotiate risk -- and the factors that modulate their risk-taking behind
the wheel.
In the study, reported in the journal Social Cognitive
and Affective Neuroscience, 14-year-old subjects completed a simulated
driving task while researchers tracked blood flow in their brains.
Laurence Steinberg, a professor of psychology at Temple
University, developed the driving task and evaluated how the presence of peers
influenced teen risk-taking, Telzer said.
"He found that peers significantly increase risk-taking
among teens," Telzer said. "I wanted to know whether we could reduce
risk-taking by bringing a parent into the car."
Telzer and her colleagues observed that teens driving alone
found risky decisions rewarding. Blood flow to the ventral striatum, a
"reward center" in the brain, increased significantly when teen
drivers chose to ignore a yellow stoplight and drove through the intersection
anyway.
Previous research has demonstrated that the ventral striatum is
more sensitive to rewards in adolescence than during any other developmental
period, Telzer said.
"The prevailing view is that this peak in reward
sensitivity in adolescence underlies, in part, adolescent risk-taking,"
she said.
A mother's presence, however, blunted the thrill of running the
yellow light, Telzer and her colleagues found.
"When mom is there, the heightened ventral striatum
activation during risky decisions goes away," Telzer said. "Being
risky, it appears, is no longer rewarding in the presence of mom."
Not surprisingly, teens stepped on the brakes significantly more
often at yellow lights when their moms were present than when they were alone.
"The teens go from about 55 percent risky choices to about
45 percent when their mom is watching," Telzer said. "That's a big
effect."
Another brain region, the prefrontal cortex, kicked into gear
when the teens put on the brakes -- but only when their mom was watching, the
researchers found. The PFC is important to behavioral regulation, also called
"cognitive control," Telzer said.
"When they make safe decisions, when they choose to stop
instead of going through that intersection, the prefrontal cortex comes
online," she said. "It's activated when mom is there, but not when
they're alone." (See infographic.)
The PFC (the control center) and the ventral striatum (the
reward center) are key brain regions involved in adolescent risk-taking
behavior, Telzer said. But in the absence of a well-developed control center,
adolescents are more susceptible to the stimulating allure of risky behavior.
"Here we're showing that mom reduces the rewarding nature
of risk-taking and increases activation of the prefrontal cortex during safe
behavior," Telzer said. "And so these two mechanisms help adolescents
to think twice before running the intersection. A parent's presence is actually
changing the way the adolescent is reasoning and thinking about risk -- and
this increases their safe behavior."
Story Source:
The above story is based on materials provided by University of Illinois at
Urbana-Champaign. Note: Materials may be edited for content
and length.
Journal Reference:
E. H. Telzer, N. T. Ichien, Y. Qu. Mothers know best:
redirecting adolescent reward sensitivity toward safe behavior during risk
taking. Social Cognitive and Affective Neuroscience, 2015; DOI: 10.1093/scan/nsv026
Cite This Page:
University of Illinois at Urbana-Champaign. "This is your
teen's brain behind the wheel." Science
Daily, 22 April 2015. <www.sciencedaily.com/releases/2015/04/150422122029.htm>.