Neural mechanisms underlying context-dependent shifts in risk preferences.

Studies of risky decision-making have demonstrated that humans typically prefer risky options after incurring a financial loss, while generally preferring safer options after a monetary gain. Here, we examined the neural processes underlying these inconsistent risk preferences by investigating the evaluation of gains and losses, and demonstrating how these responses can impact subsequent preference for either risky or safe choice options. Participants performed a task while undergoing fMRI in which they experienced both gains and losses. Immediately following a gain or loss, participants decided to either play or pass on a "double-or-quits" gamble. The outcome of the gamble could either double or eliminate their initial gain (from the time-estimation task) or redeem or double their initial loss. If they chose not to play this gamble, they retained the initial gain or loss. We demonstrate a shift in risk-taking preferences for identical sets of gambles as a function of previous gains or losses, with participants showing a greater preference towards riskier decisions in the context of a prior loss. An interaction between evaluating gain/loss contexts and subsequent behavioral risk pattern revealed an increased BOLD response in the ventromedial prefrontal cortex (vmPFC), with stronger responses for both gambling in a loss context and safety in a gain context. This suggests that the vmPFC is responsible for integrating these contextual effects, with these processes impacting on subsequent risky choice.