Adolescent cognitive control and reward processing: implications for risk taking and substance use.

Adolescence is a unique, transitional period of human development. Once hallmark of this period is progressive improvements (relative to children) in cognitive control, core mental abilities enabling the 'top-down', endogenous control over behavior. However, as adolescents transition to more mature (adult) levels of functioning, limitations still exist in the ability to consistently and flexibly exert cognitive control across various contexts into the early twenties. Adolescence is also marked by peaks in sensation, novelty, and reward seeking behaviors thought to stem from normative increases in responsiveness in limbic and paralimbic brain structures, beginning around the onset of puberty. Asynchronous maturation in these systems during the adolescent period likely contributes to immature decision-making, strongly influenced by 'bottom-up' reward processes, and may help explain noted increases in risk taking behavior during adolescence. In this paper, structural and functional maturation in brain systems supporting reward and cognitive control processing are reviewed as a means to better understand risk taking. Particular emphasis is placed on adolescents' experimentation with drugs as a specific example of a risky behavior.