Investigating Avoidance Behavior and Its Effects on Fear-Potentiated Startle Using a Novel Avoidance Paradigm

Abstract

Previous research on avoidance in fear conditioning has focused on relatively simple tasks that require little action (e.g. a single button press). Little is known about the effects of task difficulty and the level of vigor necessary to complete avoidance on the physiologically conditioned fear response. In the present pilot study, we used a novel avoidance paradigm to investigate how varying the distance to a safety area affects avoidance behavior and fear-potentiated startle (FPS). After conditional fear acquisition with a shock as the unconditioned stimulus (US), the participants were able to avoid the shock by maneuvering a figure into the safety area during a confined movement period. Startle amplitude was measured both before and after the movement period. We hypothesized that the effects of distance to safety would be comparable to those of proximity to threat. The comparison proved to be highly difficult as the startle reflex appeared to be affected by a variety of factors that could not be controlled for. Individual variability with regard to movement behavior was found. We conclude that the current avoidance paradigm appears to be unsuitable for examining FPS; nonetheless, it could be useful in investigating individual and group differences in avoidance behavior.