Increase in avoidance of learnt fear via unconditioned stimulus revaluation

Not all individuals develop anxiety-related disorders by direct exposure to trauma. Other pathways, such as retrospectively revaluating neutral past events as more aversive than they were, could also lead to the development of fear. This process has been modelled in the laboratory by pairing a neutral conditioned stimulus (CS) with a low intensity unconditioned stimulus (US). The intensity of the US is later increased and hence revaluated as aversive, leading to the development of conditioned fear to the CS. The present study (n = 66) examined whether avoidance of learnt fear, a feature of anxiety-related disorders, could develop via this retrospective revaluation process. In a sensory preconditioning protocol, two neutral preconditioning stimuli (PSs) were paired with two neutral CSs. Each of these CSs were then associated with a distinct low intensity US. In the following manipulation phase, one US increased in intensity for one group (the Revaluation group) while the same US remained at the same intensity for another group (the Control group). In test, the Revaluation group showed stronger avoidance responses to the PS associated with the revaluated CS compared to the Control group. However, there was no evidence of conditioned fear developing to the revaluated CS, nor did anxiety-related risk factors appear to influence the rate of avoidance of learnt fear. These findings suggest that avoidance of learnt fear can be increased via US revaluation, even after a seemingly benign experience, and highlight potential therapeutic interventions aimed at reducing avoidance of learnt fear.