Overlapping and Distinct Neural Systems Code for Subjective Value during Intertemporal and Risky Decision Making

During decision making, valuation of different types of rewards may involve partially distinct neural systems, but efficient choice behavior requires a common neural coding of stimulus value. We addressed this issue by measuring neural activity with functional magnetic resonance imaging while volunteers processed delayed and probabilistic decision options. Behaviorally, participants discounted both types of rewards in a hyperbolic manner, and discount rates, reflecting individual preferences, varied considerably between participants. Ventral striatum and orbitofrontal cortex showed a domain-general coding of subjective value regardless of whether rewards were delayed or probabilistic, strongly implicating these regions in the implementation of a common neural currency of value. In contrast, fronto-polar and lateral parietal cortex, as well as a region in the posterior cingulate cortex only correlated with the value of delayed rewards, whereas superior parietal cortex and middle occipital areas only represented the value of probabilistic rewards. These results suggest a mechanism for the neural coding of subjective value in the human brain that is based on the combination of domain-general and domain-specific valuation networks.