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Many researchers have used the standard Iowa Gambling Task (IGT) to assess decision-making in adolescence given increased risk-taking during this developmental period. Most studies are cross-sectional and do not observe behavioral trajectories over time, limiting interpretation. This longitudinal study investigated healthy adolescents' and young adults' IGT performance across a 10-year span. A total of 189 individuals (aged 9-23 at baseline) completed a baseline session and were followed at 2-year intervals yielding 5 time-points. IGT deck contingencies were shuffled over time to reduce practice effects. IGT performance (good minus bad decisions) was measured at each assessment point and separated into 3 metrics: overall performance (all blocks), decision-making under ambiguity (blocks 1 and 2), and decision-making under risk (blocks 3, 4, and 5). Covariates included estimated intelligence and affective dispositions as measured by the Behavioral Inhibition and Activation System (BIS/BAS) Scales. A linear effect of age yielded the best fit when comparing linear and quadratic effects of age on overall IGT performance. Age and intelligence positively predicted overall performance, whereas affective approach tendencies (BAS) negatively predicted overall performance. Practice effects were observed and controlled for. Models of ambiguity and risk metrics yielded different patterns of significant predictors. Age predicted better performance and affective approach tendencies predicted worse performance for both metrics. Intelligence was a significant predictor for risk, but not ambiguity. This longitudinal study extends prior work by showing age-related improvements in reward-based decision-making and associating those improvements with cognitive and affective variables. Implications of the results for adolescent development are discussed.

Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity (i.e., sensitivity of the behavioral approach system [BAS]) and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities) lead to these phenomena. The present study is the first longitudinal investigation of changes in reward (i.e., BAS) sensitivity in 9- to 23-year-olds across a 2-year follow-up. Support was found for increased reward sensitivity from early to late adolescence, and evidence was found for decline in the early 20s. This decline is combined with a decrease in left nucleus accumbens (Nacc) volume, a key structure for reward processing, from the late teens into the early 20s. Furthermore, we found longitudinal increases in sensitivity to reward to be predicted by individual differences in the Nacc and medial orbitofrontal cortex (OFC) volumes at baseline in this developmental sample. Similarly, increases in sensitivity to threat (i.e., behavioral inhibition system sensitivity) were qualified by sex, with only females participants experiencing this increase, and predicted by individual differences in lateral OFC volumes at baseline. (Contains 4 tables, 2 figures, and 1 footnote.)

Behavioral activation that is associated with incentive-reward motivation increases in adolescence relative to childhood and adulthood. This quadratic developmental pattern is generally supported by behavioral and experimental neuroscience findings. It is suggested that a focus on changes in dopamine neurotransmission is informative in understanding the mechanism for this adolescent increase in reward-related behavioral activation and subsequent decline into adulthood. Evidence is presented to indicate that incentive-reward motivation is modulated by mesoaccumbens dopamine, and that it increases in adolescence before declining into adulthood because of normative developmental changes at the molecular level. Potential mechanisms of variation in functional mesoaccumbens dopamine transmission are discussed with a focus on the interplay between tonic and phasic modes of dopamine transmission in modulating both general incentive-motivational biases and the efficacy of reward learning during exposure to novel reward experiences. Interactions between individual difference factors and these age-related trends are discussed. (Contains 2 tables and 1 figure.)

Healthy adolescents (79 girls, 66 boys), ages 9-17, completed the Iowa Gambling Task (IGT; A. Bechara, A. R. Damasio, H. Damasio, & S. W. Anderson, 1994) as well as working memory (digit span) and behavioral inhibition (go/no-go) tasks. Cross-sectional age-related changes were seen on all 3 tasks. Gender differences were seen in IGT deck preference and attentional variables (i.e., go/no-go hit rate and forward digit span). After age, gender, and general intellectual abilities were controlled for, IGT performance was not predicted by working memory or behavioral inhibition scores. Findings suggest that the ventromedial prefrontal cortex or its connections are functionally maturing during adolescence in a manner that can be distinguished from maturation of other prefrontal regions. Development of these functions may continue into young adulthood.

Healthy adolescents (79 girls, 66 boys), ages 9-17, completed the Iowa Gambling Task (IGT; A, Bechara, A. R. Damasio, H. Damasio, & S. W. Anderson, 1994) as well as working memory (digit span) and behavioral inhibition (go/no-go) tasks. Cross-sectional age-related changes were seen on all 3 tasks, Gender differences were seen in IGT deck preference and attentional variables (i.e., go/no-go hit rate and forward digit span). After age, gender, and general intellectual abilities were controlled for. IGT performance was not predicted by working memory or behavioral inhibition scores. Findings suggest that the ventromedial prefrontal cortex or its connections are functionally maturing during adolescence in a manner that can be distinguished from maturation of other prefrontal regions. Development of these functions may continue into young adulthood.