Comparing Neural Signatures of Risky Decision-making and Guaranteed Reward Processing Using a Modified Balloon Analogue Risk Task and Multi-Echo Imaging.

Risky decision making is a fundamental human behavior involving multiple cognitive processes. Understanding how these processes are represented in the brain offers critical insights into decision-making, development, and vulnerabilities to psychopathology. However, functional magnetic resonance imaging (fMRI) research of decision-making under risk and reward often does not clearly distinguish between risky decision processes and response to guaranteed reward and has limited sensitivity to deep subcortical regions, constraining our contributions. In this study, we present a modified Balloon Analogue Risk Task completed under a multi-echo fMRI protocol meant to enhance subcortical signal. Forty-eight participants inflated virtual balloons across three conditions: risky reward, guaranteed reward, and neutral. GLM analyses revealed increased signal in orbitofrontal cortex, anterior insula (AI), striatum and a brain stem nuclei, ventral tegmental area (VTA), during risky reward decision versus guaranteed rewards conditions. Multivariate analysis identified the AI as a key predictor of the risky decision condition, outperforming striatal and VTA contributions. These results suggest risky decision-making shows greater recruitment of reward-relevant regions and illuminates putative neurobiological mechanisms associated with risky decision making relative to guaranteed and non-contingent reward. The study also provides a new tool to enhance the resolution of human neuroscience research on risk-taking across the lifespan and vulnerabilities to psychopathology.