A new look at the adolescent brain: It's not all emotional chaos

Adolescence is often described as a tumultuous time, where heightened reactivity and impulsivity lead to negative behaviours like substance abuse and unsafe sexual activity. Previous research has pointed to the immature adolescent brain as a major liability, but now, a unique study reveals that some brain changes associated with adolescence may not be driving teens towards risky behaviour but may actually reflect a decrease in susceptibility to peer pressure. The findings, published by Cell Press in the March 10 issue of the journal Neuron, provide a more complete perspective of the neural systems associated with adolescent behaviour.

Subcortical neural systems associated with emotional responses are thought to mature earlier than the higher cortical areas that regulate affective responses in adults, and they are often implicated in the impulsive and emotional behaviour that is associated with adolescence. However, there is a lack of concrete evidence linking these behavioural changes with neural development. 'It is important to determine whether developmental changes in the neural response to emotional displays are associated with changes in susceptibility to peer influence or engagement in risky behaviour,' explains lead study author, Dr Jennifer H. Pfeifer from the University of Oregon.

Dr Pfeifer and colleagues examined emotional development longitudinally across the transition from late childhood to early adolescence by recording brain activity while study participants observed images of different emotional expressions. Subjects also completed surveys designed to measure resistance to peer pressure and risky behaviour. The researchers observed that responses to the facial displays exhibited general and emotion-specific changes in multiple brain regions, including the ventral striatum (VS) and the amygdala. The VS is most commonly associated with reward processing but has recently been implicated in regulation of emotions. Interestingly, increases over time in VS activity were associated with decreases over time in peer pressure susceptibility and risky behaviour.

Taken together, the findings suggest that VS responses to emotions may play a positive regulatory role in adolescent interpersonal functioning. 'Perhaps if teenagers can better modulate their emotional response to a peer who is trying to persuade them to do something unwise, they will be less susceptible to that external influence,' suggests Dr Pfeifer. 'Our findings underline the need to explore whether basic training in emotion regulation techniques may support resistance to peer influence and prevent risky behaviour or delinquency during the transition to adolescence and beyond, particularly for at-risk individuals with a history of behavioural misconduct and vulnerability to peer pressure.'