The adolescent brain may be especially sensitive to new memories, social stress and drug use, suggests a new study.
Adolescence, like infancy, has been said to include distinct sensitive periods during which brain plasticity is heightened; but in a review of the neuroscience literature, University College London (UCL) researchers saw little evidence for this claim.
However, a small number of studies do support that memory formation, social stress and drug use are processed differently in the adolescent brain compared to other periods of life. Conclusively proving that adolescent sensitive periods exist will require studies comparing children, adolescents, and adults and will need to take into account individual differences in adolescent development, says Delia Fuhrmann, adding that adolescents are much more likely than children to choose their own environments and choose what they want to experience.
Humans retain some plasticity, changes in brain and behavior in response to environmental demands, experiences, and physiological changes, throughout life. However, during sensitive periods plasticity is heightened and the brain "expects" to be exposed to a particular stimulus. For example, the brains of infants are primed to process visual input and language. The ability to form memories seems to be augmented during adolescence, one example for how it may be a sensitive period.
Memory tests in different cultures show a "reminiscence bump"; at 35 or later, we are more likely to recall autobiographic memories from ages 10 to 30 years than memories prior or subsequent. The recall of music, books, films, and public events from adolescence is also superior compared with that from other periods.
Further, they point out that simple aspects of working memory or ongoing information processing may reach maturity in childhood, while more complex, self-organized working memory abilities continue to improve during early adolescence and recruit frontal brain regions that are still developing. Many mental illnesses have their onset in adolescence and early adulthood, possibly triggered by stress exposure.
The UCL team explored studies indicating that both social stress and social exclusion have a disproportionate impact during adolescence. They also argue that adolescence may be a vulnerable period for recovery from these negative experiences. The study is published in Trends in Cognitive Sciences