A prevailing theory is that an adolescent brain has a heightened sensitivity to a variety of stimuli, much like that of an infant’s.
Although new research does not entirely support the theory of heightened brain plasticity during teenage years, investigators did find evidence that memory formation, social stress, and drug use are processed differently in the adolescent brain compared to other periods of life.
University College London (UCL) researchers say additional studies are needed to confirm or deny the belief that a more moldable brain exists during adolescence.
“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,” said Delia Fuhrmann, a Ph.D. student in UCL’s Institute of Cognitive Neuroscience Developmental Group.
“Adolescents are much more likely than children to choose their own environments and choose what they want to experience.”
Study results have been published in the journal Trends in Cognitive Sciences.
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 accentuated during adolescence, a potential example for how it may be a sensitive period.
Memory tests in different cultures show a “reminiscence bump” at 35 or later. This is a time 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.
Research also suggests that simple aspects of working memory or ongoing information processing may reach maturity in childhood. Conversely, more complex, self-organized working memory abilities continue to improve during early adolescence and recruit frontal brain regions that are still developing.
“Working memory can be trained in adolescents, but we don’t know how these training effects differ from other age groups,” Fuhrmann said. “Such data would be useful for planning curricula because it would tell us what to teach when.”
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.
“Adolescents are slower to forget frightening or negative memories,” said Fuhrmann. “This might mean that some treatments for anxiety disorders, which are based on controlled exposure to whatever a patient is afraid of, might be less effective in adolescents and alternative treatments might be needed.”
Investigators also found studies that showed adolescence is also a time of heightened engagement in risky health behaviors, such experimenting with alcohol and other drugs. Young adolescents seem to be particularly susceptible to peer influence on risk perception and risk taking compared with other age groups.
Source: Cell Press/EurekAlert