Task engagement decreases pain perception in response to controlled pressure pain

Abstract

Background: To serve as a signal of potential threat a stimulus perceived as painful must achieve salience. The salience of a pain stimulus and its disruptive function on cognitive ability is well documented. This study investigates the hypothesis that increasing task demand reduces saliency of a painful stimulus and modifies observers’ pain perception. Method: In a controlled within subjects laboratory experiment, healthy adults (N=22) rated subjective pain level in response to a painful stimulus while performing a standardised ‘n-back’ visual working memory task varying in level of difficulty; 1-back (easy) vs 3-back (hard). Using a custom-built device, physical force (pain stimulus) was gradually increased over time on the participants’ fingertip. Force (Newtons) was recorded when participants rated the pain level as a 5 on a 10-point scale (1 signalling pain threshold and 10 pain tolerance) when engaged in the easy and difficult visual memory tasks and when there was no task. No-task measurements were made before and after visual memory blocks. Findings: Measured pain stimulus (force applied to the fingertip in Newtons) a participant would attribute a level of 5 (pain perception) was significantly greater on task blocks compared to no-task blocks, varying the task difficulty had no significant effect. During the task individuals could significantly endure more force applied (40% more) before rating pain as 5. Conclusion: Engaging in a cognitively demanding task, irrespective of level of difficulty, competes with the pain stimulus to reduce its subjective intensity. Task engagement presents an effective and pleasant strategy for pain management.