Task-Based Value Generalization Correlates With Positive Overgeneralization and Bipolar Symptoms
Positive overgeneralization -- the tendency to generalize from specific successes to broad expectations of future reward -- has been linked to vulnerability to mania. Because positive overgeneralization has only been assessed using self-report measures, we have limited insight into the underlying cognitive process. Here, we introduce a behavioral paradigm that quantifies how reward generalizes to novel stimuli, and characterize individual generalization profiles by fitting psychometric functions to choice data. In an online transdiagnostic study (N = 163), broader task-based generalization was associated with both higher self-reported positive overgeneralization and subclinical bipolar traits. Response times provided converging evidence: a smaller increase in response time as stimuli became less similar to the rewarded stimulus was associated with higher positive overgeneralization. In computational simulations, we show that self-efficacy, operationalized as the relative weight placed on the best and worst available future actions, shapes generalization, with more weight on the best possible action broadening the spread of expected reward to similar states. Together, these findings show that positive overgeneralization can be measured behaviorally, and identify one computational factor that may determine how broadly reward generalizes.