Neural tracking of subjective value under risk and ambiguity in adolescence

Abstract

Although many neuroimaging

studies on adolescent risk-taking focus on brain activation during

outcome valuation, less attention is paid to the neural correlates of

choice valuation. Subjective choice valuation may be particularly influenced by whether a choice presents risk (known probabilities) or ambiguity (unknown probabilities), which has rarely been studied in developmental samples. Therefore we examined the neural tracking of subjective value during choice under risk and ambiguity in a large sample of adolescents (N=188, 12-22 years). Specifically, we investigated which brain regions tracked subjective value coding under risk and ambiguity. A model-based approach to estimate individuals' risk and ambiguity attitude showed that there was prominent individual variation in individuals' aversion to risk and ambiguity. Furthermore, participants subjectively experienced the ambiguous options as riskier compared to the risky options. Subjective value tracking under risk was coded by activation in ventral striatum and superior parietal cortex. Subjective value tracking under ambiguity was coded by dorsolateral prefrontal cortex (PFC) and superior temporal gyrus activation. Finally, overlapping activation in the dorsomedial PFC was observed for subjective value under both conditions. Together, this is the first study to chart brain activation patterns for subjective choice valuation under risk and ambiguity in an adolescent sample, and shows that the building blocks for risk and ambiguity processing are already present in early adolescence. Finally, we highlight the potential of combining behavioral modelling with fMRI for investigating choice valuation in adolescence, which may ultimately aid in understanding who takes risks and why.