Effects of intolerance of uncertainty on subjective and psychophysiological measures during fear acquisition and delayed extinction

Individuals who score high in self-reported Intolerance of Uncertainty (IU) tend to find uncertainty unacceptable and aversive. In recent years, research has shed light on the role of IU in modulating subjective (i.e. expectancy ratings) and psychophysiological responses (i.e. skin conductance) across different classical fear conditioning procedures. In particular, during immediate extinction higher IU is associated with disrupted safety learning. However, there remain gaps in understanding how IU, in comparison to other negative emotionality traits (STAI-T), impact different types of subjective and psychophysiological measures during different classical fear conditioning procedures. In our exploratory study, we analyzed IU, STAI-T, subjective (i.e. fear ratings) and psychophysiological (i.e. skin conductance, auditory startle blink) data recorded during fear acquisition training and 24 h-delayed extinction training (n = 66). Higher IU, controlled for STAI-T, was: (1) significantly associated with greater fear ratings to the learned fear cue during fear acquisition training, and (2) at trend associated with greater fear ratings to the learned fear versus safe cue during delayed extinction training. Null results were observed for both IU and STAI-T in relation to skin conductance and auditory startle blink during fear acquisition training and delayed extinction training. These results add to and extend our current understanding of the role of IU on subjective and physiological measures during different fear conditioning procedures particularly that of subjective fear ratings during acquisition and delayed extinction training. Implications of these findings and future directions are discussed.