The role of safety signals in fear extinction: An analogue study

•We configured a conditioned stimulus and a safety signal.•During extinction the presence or absence of the safety signal was evaluated.•The safety signal did not appear to interfere with extinction at follow-up.

Background and objectivesSafety signals are conditioned inhibitory stimuli that indicate the absence of unconditioned stimuli. It is not clear whether the presence of safety signals is detrimental or beneficial in extinction-based interventions. The purpose of this study was to evaluate the effect of safety signals on autonomic and expectancy fear-related responses.MethodsFollowing the conditional discrimination paradigm (AX +, BX-), undergraduate students (N = 48) underwent an aversive conditioning procedure, while safety signals were experimentally created. Participants were randomly assigned to one of two conditions during extinction: presence or absence of safety signals.ResultsSignificant reductions of fear-related responses were found in both groups. Expectancy measures showed that the presence of safety signals did not interfere with reduction of fear related responses at follow-up.LimitationsThe analogue nature of the study affects its ecological validity. There are some methodological issues.ConclusionsSafety signals did not interfere with extinction learning. Attention may be a mechanism associated with the maintenance of fear responses.