Neural Correlates of Uncertainty Processing During Decision-Making in Individuals with Different Levels of Worry Proneness

Background: Worry proneness has been proposed to influence uncertainty processing; however, its neural mechanisms during different forms of uncertain decision-making remain poorly understood. This study used functional magnetic resonance imaging (fMRI) to investigate behavioral and neural responses associated with risky and ambiguous decision-making and to examine how individual differences in worry proneness relate to uncertainty-related neural processing. Methods: Participants completed a modified ambiguity–risk decision-making task during fMRI scanning. Whole-brain, region-of-interest (ROI), and continuous PSWQ-based correlation analyses were conducted to characterize neural responses associated with uncertainty type and individual differences in worry proneness. Results: Behavioral analyses revealed no significant effects of worry proneness or uncertainty type on gambling choices or reaction times. Whole-brain analyses showed that risky decisions elicited greater activation than ambiguous decisions in the right insula, right inferior parietal lobule, and left supramarginal gyrus, whereas ambiguous decisions preferentially recruited the right superior temporal gyrus. An exploratory peak-level interaction between worry proneness and uncertainty type was identified in the right middle frontal gyrus (BA6), with higher worry proneness associated with lower BA6 activation during risky decision-making. Continuous analyses further showed that BA6 activation during risky decisions was negatively correlated with PSWQ scores. ROI analyses demonstrated greater activation during risky than ambiguous decisions in the bilateral caudate nucleus, left insula, and right inferior frontal gyrus. Conclusions: These findings demonstrate that risky and ambiguous decision-making are associated with partially dissociable patterns of neural activation. Worry proneness was not associated with widespread alterations in behavioral performance or uncertainty-related neural responses; however, exploratory analyses identified localized associations between worry proneness and prefrontal neural responses during risky decision-making. These findings suggest that individual differences in worry proneness may be related to selective variation in specific neural processes rather than broad alterations in the neural systems supporting uncertainty processing.