Reduced cortical complexity in ventromedial prefrontal cortex is associated with a greater preference for risky and immediate rewards.

In our everyday lives, we are often faced with situations in which we make choices that involve risky or delayed rewards. However, the extent to which we are willing to accept larger risky (over smaller certain) or larger delayed (over smaller immediate) rewards varies across individuals. Here, we investigated the relationship between cortical complexity in the medial prefrontal cortex and individual differences in risky and intertemporal preferences. We found that reduced cortical complexity in left ventromedial prefrontal cortex (vmPFC) was associated with a greater preference for risky and immediate rewards. In addition to these common structural associations in left vmPFC, we also found associations between lower cortical complexity and a greater preference for immediate rewards that extended into the left dorsomedial prefrontal cortex and right vmPFC. Furthermore, these structural associations occurred in a context where a preference for risky rewards was correlated with a preference for delayed rewards across individuals. These results suggest that risk and intertemporal preferences are distinct but related, and likely influenced by multiple neurocognitive processes, with cortical complexity in vmPFC reflecting one shared aspect possibly related to impulsiveness in terms of risky and impatient economic choice. Future work should elucidate the complex relationships between brain structure and behavioral preferences.