The Reduction of Fear of Movement-related Pain

Abstract

Previous research indicates that reducing fear of movement-related pain is hampered by engaging in safety-seeking behavior. We tested the hypothesis that fear reduction is only disrupted by behavior that serves a pain-avoidance goal (safety-seeking), but not when it is serving an achievement goal. Using the voluntary joystick movement paradigm, fear of a painful joystick arm movement was successfully acquired by repeatedly pairing this joystick movement with a painful electrocutaneous stimulus (unconditioned stimulus [pain-US]) and this fear was subsequently extinguished using a Pavlovian extinction procedure. During extinction, a Safety group and Reward group both pressed a safety button, whereas a third Control group did not. Pain-US expectancy and fear of movement-related pain ratings show a gradual fear reduction in the Control Group, but a return of fear when the button is pressed to avoid the pain-US (Safety group). When the same button is used to attain a reward (Reward group), subsequent return of fear is attenuated. In addition, we investigated the reliability of the return of fear in the Safety group and Reward group, using a customized Reliable Change Index. This index confirms that the return of fear was only reliable in the Safety group, and that this return of fear is associated with more perceived control over the nonoccurrence of the pain-US when pressing the button. These results highlight the importance of motivational context in understanding the role of safety-seeking behavior in exposure-based therapies.