These findings provide neurobiological empirical support for a dissociation of the constructs related to risk-taking and reward sensitivity from that of impulsivity with the former showing an curvilinear pattern and the latter a linear pattern (see Figure 2 B). Thus adolescent choices and behavior cannot be explained by impulsivity or protracted development of the prefrontal cortex alone. Rather, motivational subcortical regions must be considered to elucidate why adolescent behavior is not only different from adults, but from children as well. Thus, the ventral striatum appears to play a role in levels of excitement 82, 91 and positive affect 15 when receiving rewards, as well as the propensity for sensation-seeking and risk-taking 16, 91. More importantly, these findings suggest that during adolescence, some individuals may be more prone to engage in risky behaviors due to developmental changes in concert with variability in a given individual’s predisposition to engage in risky behavior, rather than to simple changes in impulsivity.
