Task interference and distraction efficacy in patients with fibromyalgia: an experimental investigation

Pain has the capacity to interfere with daily tasks. Although task interference by pain is largely unintentional, it can be controlled to a certain extent. Such top-down control over pain has been thought to be reduced in fibromyalgia patients. In this study, we investigated task interference and distraction efficacy in fibromyalgia patients (FM) and a matched healthy control group. Forty-nine fibromyalgia patients and 49 heathy volunteers performed as quickly as possible (a) a visual localization task in the presence of non-painful vibrating or painful electric somatic stimuli, and (b) a somatosensory localization task (using non-painful or painful stimuli). Participants reported on their experience of the somatic stimuli on some of the trials during both localisation tasks. Results indicated that pain interferes with performance of the visual task, in both FM patients and healthy individuals. Furthermore, participants experienced the pain stimulus as less intense when directing attention away from the pain than when focusing on the pain. Overall, task performance of FM patients was slower compared to the task performance in the healthy control group. In contrast to our hypotheses, FM patients and healthy volunteers did not differ in the magnitude of the interference effect and distraction-efficacy. In conclusion, current study provides support for contemporary theories claiming that attention modulates the experience of pain and vice versa. However, no evidence was however found for an altered attentional processing of pain in fibromyalgia patients. Furthermore, results indicate that task interference and distraction-efficacy are not just two sides of the same coin.