Incremental dual-task paradigm to investigate pain attenuation by task: the role of difficulty and light

Abstract

Introduction: There is evidence that performing a task can attenuate perceived pain intensity because task and pain processing compete for shared attentional resources. Here we tested whether increasing attention to the task could modulate the task attenuation of pain intensity by manipulating either task difficulty or ambient light to increase alertness. Methods: We used a novel incremental dual-task paradigm which required participants to continuously monitor the task and the pain intensity on their fingertip. Force was incrementally applied to the participants’ fingertip while they concurrently engaged in a task until they reported a moderate pain intensity. In Experiment 1, 22 participants performed an “easy†or “difficult†working-memory task with coloured shapes. In Experiment 2, 20 participants performed an “easy†working-memory task with letters while immersed in ambient light which had high or low melanopic content. Participants stopped the task when the pain intensity on their fingertip reached Level 5 or 6 on a 10-point numeric rating scale. We recorded the force (measured in Newton) at this pain intensity during the task, as well as before and after the task. Results: In Experiments 1 and 2, we found that force was significantly greater during the task compared to no-task blocks, but that varying task difficulty or ambient light did not affect force measurements. Conclusion: Task engagement can reduce perceived pain intensity and may provide a strategy for pain management.