- Adolescence is a
crucial stage for brain development
- The learning process
of an adolescent is different from that of an adult
hippocampus and striatum in the brain enhance a teen's ability to learn and
Adolescence is a
stage of rapid brain growth. During this stage, adolescents experience
improvements in basic thinking abilities such as attention, memory, processing
speed, organization, and metacognition. Studies conducted on adolescents brain
development often focused on the negative effects of reward-seeking behavior.
But a new study suggests that the teens' sensitivity to reward could be part of
an evolutionary adaptation to learn from their environment.
uncovered two distinct regions in the adolescent brain that enhance teens'
ability to learn and form memories. The coordinated activity of the two brain
regions- hippocampus and striatum - were associated with the learning circuit
in the teens' brain.
‘A coordinated activity of striatum and hippocampus in the adolescent's brain may help them learn by enhancing memory.’
the adolescent brain often focus on the adverse effects of teens' reward-seeking
behavior. However, we hypothesized that this tendency might be tied to better
learning," said Daphna Shohamy, Ph.D., a principal investigator at
Columbia's Mortimer B. Zuckerman Mind Brain Behavior Institute and associate
professor of psychology at Columbia.
combination of learning tasks and brain imaging in teens and adults, we
identified patterns of brain activity in adolescents that support learning --
serving to guide them successfully into adulthood."
Brain Activity in
Davidow, a psychology postdoc at Harvard University, Dr Shohamy, and Dr Adriana
GalvŠn from the University of California, Los Angeles, conducted a study to
test whether teen's sensitivity to reward could make them better at learning
from good and bad outcomes.
involved 41 teens (ages 13-17) and 31 adults (ages 20-30), the authors focused
on a brain region called the striatum, a region of the brain which is a
critical component of the reward system. Studies have shown that striatum
coordinates the brain function from planning to decision making. But, the
striatum is well-known for its role in reinforcement learning.
simplest terms, reinforcement learning is making a guess, being told whether
you're right or wrong, and using that information to make a better guess next
time," said Davidow, first author of the study.
imagine you are given a series of cards with numbers on them and are asked to
guess the next number in the sequence. If you guess right, the striatum shows
activity that corresponds to that positive feedback, thus reinforcing your
choice," Dr. Davidow explained. "Essentially, it is a reward signal
that helps the brain learn how to repeat the successful choice again."
included an image of a butterfly and a pair of flower pictures. The
participants were asked to guess the flower on which the butterfly would land
on. When participants guessed it right, the word "correct" flashed on the
screen, and when the answer was wrong, the word "incorrect" flashed on the
When the correct or incorrect label
appeared on the screen, an unrelated image like watermelon or pencil was also
displayed. These unrelated images were used in a memory test to examine whether
the participants remembered their environment during the learning process.
showed that teens selected the right flower than the adults during the
experiment. The teens also remembered the unrelated images and did better than
adults on the memory test. The study suggests that teens have a better
memory for retaining detail about unexpected outcomes.
with Functional Magnetic Resonance Imaging (fMRI)
wanted to see what exactly happens in the brain. Dr Shohamy teamed up with Dr
GalvŠn scanned the brains of each participant with functional magnetic
resonance imaging (fMRI) while they were performing the learning tasks.
Initially, the researchers hypothesized that the teens learning abilities
were due to the hyperactive striatum. But, there
were no difference in striatal activity in the brains of the teens and adults.
But they found the difference in a new region called the hippocampus, the
brain's memory headquarters.
The hippocampus stores memories, events,
places, people, but it is not related to reinforcement learning.
compared the brains of teens to those of adults, we found no difference in
reward-related striatal activity between the two groups. We discovered that the
difference between adults and teens lay not in the striatum but a nearby region:
the hippocampus," said Dr Davidow.
reinforcement learning, the fMRI
showed activity in the hippocampus for teens but not adults. But, the
hippocampal activity coordinated with activity in the striatum.
can take from these results isn't that teens necessarily have better memory, in
general, but rather the way in which they remember is different. By connecting
two things that aren't intrinsically connected, the adolescent brain may be
trying to build a richer understanding of its surroundings during an important
stage in life," said Dr Shohamy, who is also a member of Columbia's Kavli
Institute for Brain Science.
speaking, adolescence is a time when teens begin to develop their
independence," said Dr. Shohamy. "What more could a brain need to do
during this period than jump into learning overdrive? It may be that the
uniqueness of the teen brain may drive not only how they learn, but how they
use information to prime themselves for adulthood."
are working to determine what changes occur in the brain between adolescence
and adulthood when it comes to reinforcement learning. The results of the
study could pave the way for developing new approaches for teaching teenagers.
frame something positively, it could be the case that adolescents will remember
things about the learning experience better," says Davidow. "In
everyday life, they're paying attention to their environment in a way that is
different from adults."
The study is
published in the Journal Neuron.
- Brain Development
in Young Adolescents - (http://www.nea.org/tools/16653.htm)