Avoiding at all costs? An exploration of avoidance costs in a novel Virtual Reality procedure

Approach-avoidance behaviours play a major role in the development and maintenance of anxiety disorders as repeated avoidance behaviours are assumed to prevent fear extinction. Approach-avoidance decisions (Conditioned Stimulus (CS)-avoidance and Unconditioned Stimulus (US)-avoidance) and their effect on fear extinction and renewal were investigated using a Virtual Reality fear conditioning procedure with ecologically relevant avoidance costs (temporal delay and physical effort). Participants had to choose between a safe (low approach incentive, no US) and a risky stimulus (high approach incentive, US in 75%). After differential fear acquisition and avoidance learning, participants were randomized to an Avoidance condition or No Avoidance condition during fear extinction. Fear extinction took place in either the original contingency learning context or in a new context and was followed up by a renewal test. Furthermore, the influence of trait anxiety, distress tolerance, and intolerance of uncertainty on approach-avoidance decisions was investigated. Exploratively, a second experiment with varying avoidance costs was conducted. Results were not indicative of renewal and no robust associations with the individual difference measures were found. However, results showed high (Study 1), but not low (Study 2), avoidance costs resulted in less avoidance behaviour. Even though there were no between-group differences, exploratory comparisons of avoiders and non-avoiders in both studies demonstrated that avoidance behaviours protected from extinction learning, resulting in the maintenance of retrospective US expectancies and a sustained preference for the safe stimulus. These findings provide insight in how avoidance behaviours maintain fear and how treatment might be improved by focusing on avoidance costs.