Earlier Development of the Accumbens Relative to Orbitofrontal Cortex Might Underlie Risk-Taking Behavior in Adolescents

TLDR

Adolescence is marked by risk‑taking behaviors that can lead to fatal outcomes. The study examined the neurobiological development of neural systems implicated in reward‑seeking behaviors. Thirty‑seven participants aged 7–29 underwent event‑related fMRI while completing a reward‑value parametrically manipulated paradigm. Adolescents show exaggerated nucleus accumbens activity that mirrors adult patterns in magnitude and reward sensitivity, while orbitofrontal cortex activity resembles children, suggesting that maturing subcortical systems become disproportionately activated relative to later‑maturing top‑down control systems, biasing adolescents toward immediate over long‑term gains.

Abstract

Adolescence has been characterized by risk-taking behaviors that can lead to fatal outcomes. This study examined the neurobiological development of neural systems implicated in reward-seeking behaviors. Thirty-seven participants (7–29 years of age) were scanned using event-related functional magnetic resonance imaging and a paradigm that parametrically manipulated reward values. The results show exaggerated accumbens activity, relative to prefrontal activity in adolescents, compared with children and adults, which appeared to be driven by different time courses of development for these regions. Accumbens activity in adolescents looked like that of adults in both extent of activity and sensitivity to reward values, although the magnitude of activity was exaggerated. In contrast, the extent of orbital frontal cortex activity in adolescents looked more like that of children than adults, with less focal patterns of activity. These findings suggest that maturing subcortical systems become disproportionately activated relative to later maturing top–down control systems, biasing the adolescent9s action toward immediate over long-term gains.