Intolerance of uncertainty and novelty facilitated extinction: The impact of reinforcement schedule.

Individuals who score high in intolerance of uncertainty (IU) display reduced threat extinction. Recently, it was shown that replacing threat associations with novel associations during extinction learning (i.e., presenting a novel tone 100% of the time) can promote threat extinction retention in individuals with high IU. This novelty facilitated extinction (NFE) effect could be driven by the tone's novelty or reliability. Here, we sought to address this question by adjusting the reliability of the novel tone (i.e., the reinforcement rate) during NFE. We measured skin conductance response during an associative learning task in which participants (n = 92) were assigned to one of three experimental groups: standard extinction, NFE 100% reinforcement, or NFE 50% reinforcement. For standard extinction, compared to NFE 100% and 50% reinforcement groups, we observed a trend for greater recovery of the conditioned response during extinction retention. Individuals with high IU relative to low IU in the standard extinction group demonstrated a larger recovery of the conditioned response during extinction retention. These findings tentatively suggest that NFE effects are driven by the novelty rather than the reliability of the new stimulus. The implications of these findings for translational and clinical research in anxiety disorder pathology are discussed.