Adolescence as a sensitive period of social brain development
Professor Sarah-Jayne Blakemore gives a seminar at the Oxford Mindfulness Centre
Sarah-Jayne Blakemore is a Royal Society Research Fellow and Professor of Cognitive Neuroscience at the Institute of Cognitive Neuroscience at University College London and is currently working with the Oxford Mindfulness Centre (OMC) as part of the MYRIAD project researching mindfulness and resilience in adolescence.
Sarah-Jayne opened the 2015/2016 OMC seminar series talking about her research into the adolescent brain. Her work has illuminated an area which had largely been overlooked by researchers for decades. She began by discussing her doctoral work into Schizophrenia, and how it led to her fascination with how the adolescent brain changes over time and how these changes can sometimes result in abnormal functioning. She had wanted to investigate why the existing literature suggested that brain development stopped in childhood, but the symptoms of Schizophrenia did not manifest until late adolescence. This investigation led to her deciding to focus her research on the developing of the brain in typically developing adolescents.
Sarah-Jayne acknowledged that much of what she researches, such as the stereotype that adolescents are risk-takers, has been known by researchers and parents for decades. However, despite this general understanding, until recently there was little research on the neurocognitive processes that underpin these adolescent-typical behaviours. This is particularly important given that a leading cause of teenage death is from accidents, rather than illness (Minino, 2010), and that 75% of mental health problems begin to manifest in adolescence (Jones, 2013). Sarah-Jayne’s research gives a rich and fascinating insight into why adolescents behave as they do, and highlights the differences in adolescent neurocognitive development compared with that of children and young adults. If you want to hear Sarah-Jayne talk about this work in more depth her TED talk “the mysterious workings of the adolescent brain” is a wonderful resource.
We now know that the human brain continues developing far beyond childhood, even into the twenties and thirties and demonstrates plasticity across the lifespan. However, this research is still in its infancy and a new generation of researchers, supported by the advances in brain imaging, are investigating why adolescents think and behave as they do. These adolescent-typical traits will be familiar to all those who have parented, taught or interacted with teenagers: risk-taking, self-consciousness, increased impulsivity and the importance placed on peer relationships. However, what is most interesting is that cultures who have no concept of adolescence still identify these traits in their population between the ages of 11 and 16 (Schlegel, 1995). This cross-culturally applicable identification of traits during adolescence suggests there may be a culturally-invariant biological basis for these changes in behaviour. Brain imaging research, and studies of post-mortem brains, suggest that the ongoing processes of myelination and synaptic pruning in the frontal cortex might be associated with cognitive development throughout adolescence (Huttenlocher & Dabholkar, 1997; Yakovlev & Lecours, 1967).
The cutting-edge neurological research into adolescent cognitive development is also supported by a growing body of behavioural research. Larry Steinberg and his colleagues found that adolescents were three times more likely to exhibit risky behaviour in a driving simulator when their friends were present, than when they were alone (despite being offered rewards for safe behaviour) (Gardner & Steinberg, 2005). When the adolescents were alone they were no more risky in the simulator than adults were. This study highlights the importance of peer influence on adolescents, a point that was well-explained and evidenced by Sarah-Jayne during her talk. She indicated that research by Cat Sebastian has suggested that adolescents are especially affected by social interactions (particularly social exclusion) (Sebastian et al., 2010). Research by Lisa Knoll has highlighted that young adolescents aged 12-14 were most influenced by their teenage peers (whereas older and younger participants were most influenced by adults) (Knoll et al., 2015). As Sarah-Jayne indicated, this might have significant implications for public health interventions. Government campaigns should focus on adolescents’ peers and social norms in media campaigns to highlight health risks.
Sarah-Jayne concluded by suggesting that researchers now need to build on the foundations of the research into the adolescent brain by investigating individual differences; i.e., how the differences between adolescents, such as gender, culture and life experience, might have differing effects on thinking and behaviour. A clear take-home message from the talk was that although these adolescent traits might get a negative press, they are actually healthy and necessary for development, and therefore, where possible, adolescents should not be discouraged from engaging in these behaviours and maturing through their own experiences. It also plants the intriguing possibility that adolescence is a key developmental window to teach mindfulness and resilience, a question we are pursuing with Sarah-Jayne Blakemore in the MYRIAD project.
Dr Laura Taylor
Laura read for her doctorate in Experimental Psychology at Oxford University and is currently a researcher on the MYRIAD project at the Oxford Mindfulness Centre.
Declaration of interest statement
Laura receives no payment for public engagement and has no interests to declare.
Miniño, A. M. (2010) Mortality among teenagers aged 12–19 years: United States, 1999–2006. NCHS data brief,37, 1-8.
Jones, P. B. (2013). Adult mental health disorders and their age at onset. The British Journal of Psychiatry, 202(54). 5-10.
Schlegel, A. (1995). A Cross-Cultural Approach to Adolescence. Ethos, 23(1), 15-32.
Huttenlocher, P.R.and Dabholkar, A.S. (1997). Regional differences in synaptogenesis in human cerebral cortex.Journal of Comparative Neurology, 387 (2), 167-178.
Yakovlev, P.I. and Lecours, A.R. (1967). The myelogenetic cycles of regional maturation of the brain. In: Minkowski, A. ed. Regional Development of the Brain in Early Life. Oxford, Blackwell Scientific, 3-70.
Gardner, M. and Steinberg, L. (2005) Peer influence on risk taking, risk preference, and risky decision making in adolescence and adulthood: an experimental study. Developmental Psychology, 41 (4), 625-635.
Sebastian, C., Viding, E., Williams, K., Blakemore, S. (2010). Social brain development and the affective consequences of ostracism in adolescence. Brain and Cognition, 72, 134-145.
Knoll, L. J., Magis-Weinberg, L., Speekenbrink, M., Blakemore, S. J. (2015). Social Influence on Risk Perception During Adolescence. Psychological Science, 26, 583-592.
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