Living in fear: Low-cost avoidance maintains low-level threat

Background and objectives: Excessive avoidance of potential threat is a hallmark of anxiety and is thought to maintain fear by preserving the perceived high-threat value of avoided situations. Previous research has shown that the availability of avoidance maintains low-level threat. Here, we investigated whether an opportunity to engage in avoidance in the presence of a low-threat value safety cue would maintain its perceived threat value when avoidance was unavailable. Methods: In a threat conditioning procedure, one conditional danger stimulus (CS+; A+) was followed by an aversive unconditioned stimulus (US; electric shock), and two safety stimuli (CS-; B- and C-) were never followed by the US. Next, clicking a button present during A+ avoided the scheduled US. Avoidance was then made available during C- for participants in the Experimental group but not in the Control group. In the test, all stimuli were presented without the opportunity to avoid. Threat expectancy, eyeblink startle electromyography (EMG), and skin conductance responses (SCRs) were measured. Results: Findings showed an increase in threat expectancy for only C- in the Experimental group during the test phase following avoidance learning to similar levels as during threat conditioning. Compared to the Control group, threat expectancy for both B- and C- remained higher in Experimental group. SCR and startle EMG data did not corroborate these findings. Limitations: Further research is needed to test the commonly held clinical assumption that avoidance can increase threat value. Conclusions: Low-cost avoidance maintains low-threat value of safety cues.