Adolescents show a tendency to engage in risky activities, such as dangerous driving
and unsafe sex. This has led to the suggestion that adolescents are poor decision-makers,
and are risk-seeking in general. The first two chapters of this thesis describe
studies investigating adolescent decision-making using probabilistic decision-making
tasks. In Chapter 2, the tendency to seek risk, and the ability to integrate probability
and reward information to make an optimal decision, is investigated in child,
adolescent and adult participants. The emotional response to outcomes was also
investigated. In Chapter 3, a computational approach is adopted to investigate the
role of positive and negative performance feedback (wins and losses) in a
probabilistic decision-making task in adolescents and in adults. The role of social-emotional
factors in decision-making was also investigated.
Adolescence is characterised by social and emotional development, as well as
development in the functional brain correlates of social-emotional processing.
Therefore, Chapters 4 to 6 focus on adolescent social-emotional processing using
behavioural and functional neuroimaging methods. In Chapter 4, results are
presented from a study of self-reported social and basic emotions across adolescence,
where social emotions (e.g. embarrassment) are defined as emotions that require an
awareness of others’ mental states (e.g. emotions, opinions, desires). In Chapter 5,
the neural correlates of social and basic emotion processing are investigated in
adolescents and in adults, using functional magnetic resonance imaging (fMRI).
Finally, in Chapter 6, these fMRI data are reanalysed using a technique known as
psycho-physiological interaction (PPI) analysis, to look at age-associated changes in
effective connectivity. Results are discussed in the context of social cognition and
neuroanatomical development
