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 believed to be reduced in patients with fibromyalgia (FM). In this study, we investigated task interference and distraction efficacy in patients with FM and a matched healthy control group. Forty-nine patients with FM and 49 healthy volunteers performed as quickly as possible (1) a visual localization task in the presence of nonpainful vibrating or painful electric somatic stimuli, and (2) a somatosensory localization task (using nonpainful 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 patients with FM 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 patients with FM was slower compared with the task performance in the healthy control group. In contrast to our hypotheses, patients with FM 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 found for an altered attentional processing of pain in patients with FM. Furthermore, results indicate that task interference and distraction efficacy are not just 2 sides of the same coin.