The representation of reward magnitude in the human ventral striatum and the medial orbitofrontal and ventromedial prefrontal cortex – An activation likelihood estimation meta-analysis with implications for a fundamental understanding of the human brain and substance abuse disorders

Reward maximization is a core motivation of every organism. In humans, several brain regions have been implicated in the representation of reward magnitude. Still, it is unclear whether identical brain regions play a role in reward prediction and its consumption. In this study we used coordinate-based ALE meta-analysis to determine the individual roles of the ventral striatum (vSTR) and the medial orbitofrontal cortex/ventromedial prefrontal cortex (mOFC/vmPFC) in the representation of reward. Specifically, we wanted to assess commonalities and differences in regional brain activation during the anticipation and consumption of rewards. Two independent meta-analyses of neuroimaging data from the past decade revealed a general role for the vSTR in reward anticipation and consumption, in particular when the consumed rewards occurred unexpectedly or were uncertain. For the mOFC/vmPFC the present meta-analytic data suggested a rather specific role in reward consumption. These meta-analytic data suggest that the vSTR may be involved in both the prediction and the consumption of salient rewards, and may also be sensitive to different reward magnitudes, while the mOFC/vmPFC may specifically process reward magnitude only if a factual reward is present. Collectively, these data conform with the notion that these two brain regions may subserve complementary roles in processing of reward magnitude. These findings may help understand the neural basis of substance abuse disorders.