Adolescent development of the reward system

Adolescence is a developmental period characterized by increased reward-seeking behavior. investigators have used functional magnetic resonance imaging (fmri) in conjunction with reward paradigms to test two opposing hypotheses about adolescent developmental changes in the striatum,a region implicated in reward processing. one hypothesis posits that the striatum is relatively hypo-responsive to rewards during adolescence,such that heightened reward-seeking behavior is necessary to achieve the same activation as adults. another view suggests that during adolescence the striatal reward system is hyper-responsive,which subsequently results in greater reward-seeking. while evidence for both hypotheses has been reported,the field has generally converged on this latter hypothesis based on compelling evidence. in this review,i describe the evidence to support this notion,speculate on the disparate fmri findings and conclude with future areas of inquiry to this fascinating question. © 2010 galvan.