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Subject: ADOLESCENT BRAINS SHOW REDUCED REWARD ANTICIPATION


U.S. Department of Health and Human Services

NATIONAL INSTITUTES OF HEALTH

NIH News

National Institute on Alcohol Abuse and Alcoholism (NIAAA)
http://www.niaaa.nih.gov/


EMBARGOED FOR RELEASE
Wednesday, February 25, 2004
12:00 a.m. ET

CONTACT:
NIAAA Press Office
301-443-0595
301-443-3860


ADOLESCENT BRAINS SHOW REDUCED REWARD ANTICIPATION

Adolescents show less activity than adults in brain regions that
motivate behavior to obtain rewards, according to results from the first
magnetic resonance imaging (MRI) study to examine real-time adolescent
response to incentives. The study also shows that adolescents and adults
exhibit similar brain responses to having obtained rewards. Researchers
in the Laboratory of Clinical Studies of the National Institute on
Alcohol Abuse and Alcoholism (NIAAA), one of the National Institutes of
Health, conducted the study, which appears in the February 25 issue of
the "Journal of Neuroscience" (Volume 24, Number 7).

"Understanding adolescent motivation is critical for understanding why
so many young people drink alcohol and engage in associated behaviors
such as drinking and driving and sexual risk-taking. That understanding
also will be critical for shaping prevention messages that deter such
behaviors," said Ting-Kai Li, M.D., Director, National Institute on
Alcohol Abuse and Alcoholism. "With today's report, researchers in
NIAAA's Laboratory of Clinical Studies provide an important part of the
picture."

In the MRI study, James Bjork, Ph.D., and others in the laboratory of
Daniel Hommer, M.D., scanned the brains of twelve adolescents aged 12 to
17 years and twelve young adults aged 22 to 28 years. While being
scanned, the subjects participated in a game-like scenario risking
monetary gain or loss. The participants responded to targets on a screen
by pressing a button to win or avoid losing 20 cents, $1, or $5.

For both age groups, the researchers found that the anticipation of
potential gain activated portions of the ventral striatum, right insula,
dorsal thalamus, and dorsal midbrain, with the magnitude of ventral
striatum activation sensitive to gain amount. In adolescents, however,
the researchers found lower activation of the right ventral striatum
centered in the nucleus accumbens, a region at the base of the brain
shown by earlier research (see Alcohol Researchers Localize Brain Region
That Anticipates Reward August 3, 2001 at News Releases -
http://www.niaaa.nih.gov) to be crucial for motivating behavior toward
the prospect of rewards.

"Our observations help to resolve a longstanding debate
among researchers about whether adolescents experience
enhanced reward from risky behaviors -- or seek out alcohol
and other stimuli because they require enhanced
stimulation. They also may help to explain why so many
young people have difficulty achieving long-term goals," according to
James Bjork, Ph.D., first author on the study. When the researchers
examined brain activity following gain outcomes, they saw that in both
adolescents and young adults monetary gain similarly activated a region
of the mesial frontal cortex. "These results suggest that adolescents
selectively show reduced recruitment of motivational but not
consummatory components of reward- directed behavior," state the
authors.

For interviews with Drs. Bjork and Hommer, please telephone
the NIAAA Press Office: 301/443-0595 and 301/443-3860. The article
"Incentive-Elicited Brain Activation in
Adolescents: Similarities and Differences from Young
Adults" is available after 12:00 AM February 25 at www.jneurosci.org.
MRI scans also may be accessed at "MRIs Show Adolescent-Adult
Differences in Reward Anticipation" at Graphics Gallery -
http://www.niaaa.nih.gov.)

The National Institute on Alcohol Abuse and Alcoholism, a component of
the National Institutes of Health, U.S. Department of Health and Human
Services, conducts and supports approximately 90 percent of U.S.
research on the causes, consequences, prevention, and treatment of
alcohol abuse, alcoholism, and alcohol problems and disseminates
research findings to science, practitioner, policy making, and general
audiences. Additional alcohol research information and publications are
available at www.niaaa.nih.gov.

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