Parsing apart the effects of anxiety and intolerance of uncertainty on the acquisition of fear during category fear conditioning.

Fear conditioning research can provide insight into how individuals with clinically relevant traits learn to distinguish between threatening and safe stimuli. Prior studies have found higher anxiety symptoms to be associated with increased physiological fear responses to conditioned safety stimuli (CS-) and greater intolerance of uncertainty (IU) to be associated with increased responses to conditioned threat stimuli (CS+). Yet, relationships remain unclear in the general population, particularly during acquisition, and these effects have not been explored using category fear conditioning. Unselected adults underwent category conditioning in which one category (e.g., trial unique fish; CS+) was associated with shock, and another (e.g., trial unique birds; CS-) was not. Participants rated the pleasantness of each stimulus (n = 213) and skin conductance responses (SCR; n = 171) were recorded. Additionally, participants completed the Depression, Anxiety, Stress Scale (DASS-21) and the Intolerance of Uncertainty Scale (IU). There was a significant CS type x DASS anxiety interaction for SCR data when covarying for IU during acquisition (p = .012), driven by individuals with higher anxiety demonstrating higher SCRs to the CS- (p = .019). IU did not predict SCRs or pleasantness ratings during acquisition. Our results suggest that even in an unselected sample, individuals with higher anxiety symptoms may generalize physiological fear responses from a threatening category to a safe category or have difficulty inhibiting physiological fear responses to a safe category, while leaving self-report pleasantness ratings unaffected. It appears that intolerance of uncertainty does not influence self-report or physiologic measures during acquisition in this category conditioning paradigm.