Somerville (2013). The teenage brain. Summary

A defining feature of adolescence is newfound importance of peer and romantic relationships. A shifting motivation toward social relatedness is thought to intensify the attention, salience and emotion relegated to processing information concerning social evaluations and social standing, referred to as social sensitivity.

The rise in peer interaction of adolescents is not unique to humans. The quality of peer interactions changes from friends as activity partners to peers as intimate partners on a platonic and romantic level. The socio-affective circuitry includes the amygdala, striatum and the medial prefrontal cortex. Brain areas involved in the social context are highly influenced by pubertal hormones.

Information about one’s social standing is laden with emotion. Adolescents report a greater mood change and a change in anxiety after either positive or negative social feedback. Adolescents have heightened activity in the striatum and the subgenual anterior cingulate cortex. Adolescents also recruit medial prefrontal cortex more strongly compared to adults. There is a greater release of cortisol (a stress hormone) when under social scrutiny in adolescents. Social evaluative situations induce self-consciousness and engage stress systems of the body in adolescents.

Adolescents have a tendency to speculate about the thoughts and feelings of peers. This ability is called mentalizing. Mentalizing abilities continue to mature through adolescence. The social brain includes the temporoparietal junction, superior temporal sulcus and the medial prefrontal cortex.

Social competence is the ability to achieve personal goals from interactions with others while maintaining a positive relationship with the other. Psychopathy is characterised by the lack of empathy and emotional depth, intelligence charm and eloquence and antisocial behaviour and boldness.

There are four networks of the social brain:

There are advantages and disadvantages to adolescence:

1. Advantages
   Period of increased flexibility, learning capacity and social exploration. Many mental problems disappear at the end of adolescence.
2. Disadvantages
   Mental problems often start in adolescence. Prognosis is worse for deviant behaviour that arises during adolescence.

The brain structure also changes during adolescence. Grey matter decreases and evolutionary old areas are first and areas involved in higher cognition last. This leads to different processing speed in different brain areas. Emotion recognising areas of the brain are more active in adolescents than in other people.