The development of social cognition during adolescence.

This thesis aims to investigate the development of social cognition during adolescence. Neuroimaging research has provided new evidence for significant developments of the brain during adolescence, contesting old notions that the human brain reaches maturity by childhood. The prefrontal, parietal and superior temporal cortices have been highlighted as the regions that undergo the most prolonged and profound structural change. Given the association of these brain areas with social cognitive tasks, including perspective taking, intention understanding and motor imagery, this series of studies have sought to investigate the social cognitive consequences of these brain developments. The first study in this thesis investigated the development of perspective taking between late childhood and adulthood and found that perspective taking develops in terms of efficiency and possibly strategy during adolescence. The second study investigated perspective taking in adult patients with positive symptoms of schizophrenia, including delusions of persecution, and suggested differences in processing one's own and other people's perspectives in patients compared to normal controls. The third study used fMRI to investigate the development of the neural circuitry for intentional causality during adolescence and found a shift from relatively higher activity in superior temporal cortex during adolescence to relatively higher activity in medial prefrontal cortex in adulthood. In light of motor theories of social cognition, the fourth study comprised three motor imagery experiments that investigated the development of action representation during adolescence. Results suggested that the action representation system is refined during adolescence. The final study compared action representation in typically developing adolescents and those with autism spectrum disorders and found no differences in performance between groups. Together, these studies have shown that certain social cognitive abilities develop during adolescence. The relation between social and motor cognition is discussed from a developmental perspective, as well as the link to brain maturation during adolescence. Finally speculations are made about how these processes may become dysfunctional in psychopathology