Evidence for Different Roles of Inhibitory and Prospective Intolerance of Uncertainty During Threat Discrimination Learning

Abstract

Uncertainty is a core component of threat and associated learning processes. One methodological factor impacting uncertainty in threat learning paradigms is the threat reinforcement rate, which refers to the proportion of times a cue is reinforced with an aversive stimulus. This study tested the effect of partial vs continuous threat reinforcement on threat / safety discrimination learning, as indexed by skin conductance response (SCR). Using a within-participants design, fifty-nine participants completed a task in which three colored shapes were paired with electric shock at reinforcement schedules of 100% (CS+), 50% (CS+) and 0% (CS-). In addition, the study examined the relationship between the Intolerance of Uncertainty scale (IU) and two subscales – inhibitory and prospective IU – with threat discrimination learning. The data show heightened SCR in the continuous vs partial reinforcement condition to all stimuli, but limited evidence of enhanced discrimination learning. Furthermore, no association was observed between total IU score and threat-safety discrimination. However, using a two-factor model of IU, findings showed higher inhibitory IU and higher prospective IU were associated with diminished and heightened threat discrimination, respectively. These results contribute to a fast-growing literature exploring how the uncertainty inherent to predictors of threat, individual differences in sensitivity to uncertainty, and interactions between these two factors, can shape the acquisition of threat memory.

How is “intolerance of uncertainty” (IU) measured? A systematic review of assessment tools for IU and the psychometric properties of IU questionnaires.

“…For example, the IUS-27 reported various factor models (Berenbaum et al, 2008;Buhr & Dugas, 2002;Freeston et al, 1994;Hong & Lee, 2015;Nagel et al, 2023;Sexton & Dugas, 2009), and the utilization of different factor scores in different articles led to difficulty comparing underlying aspects of IU. For the most commonly used IU questionnaire, IUS-12, although the Prospective IU (P-IU) and Inhibitory IU (I-IU) factors have been found to associate with distinct relevant constructs (Hong & Lee, 2015), and the factor scores of P-IU and I-IU have been commonly used in recent studies to explore the underlying mechanism of different aspects of IU (e.g., D. Johnson et al, 2023), the use of subscale scores remains questionable. It is recommended to apply the total score of IUS-12, rather than subscale scores, as the general IU factor has been shown to explain more unique variance than the two subscale factors (Hale et al, 2016;Huntley et al, 2020;Shihata et al, 2018;Wilson et al, 2020).…”