The adolescent brain : unraveling the neural mechanisms of cognitive and affective development

Abstract

Adolescence is often characterized as a period of increased risk taking and impulsive behavior. Researchers have constructed brain-based models to explain the higher prevalence of risk taking during adolescence. It has been hypothesized that brain regions for cognitive control develop relatively slow compared to 'affective' brain regions. An imbalance between the maturity of these brain regions is thought to underlie the increased incidence of risk taking during adolescence. However, results on functional brain development remain contradictory and few studies have investigated the assumptions of imbalance models in large-scale longitudinal studies. In this PhD thesis both cognitive and affective aspects of development were investigated using a combination of functional and structural MRI data, hormonal measures and behavioral assessments, capturing the whole range of adolescence in a large sample of children, adolescents and adults between 8 and 27 years old. The results indicated that, contrary to predictions from imbalance models, brain regions for cognitive control could be recruited even by young children and adolescents, but in different situations than adults. The results have implications for the construction of new theoretical frameworks and may eventually contribute to educational interventions that are better tailored to both the challenges and possibilities of the adolescent brain.