Effects of activity interruptions by pain on pattern of activity performance - an experimental investigation

Background and aims: Suspending an ongoing activity with the intention to resume it again later is a natural response to pain. This response facilitates coping with the pain, but it may also have negative consequences for the resumption and performance of the activity. For example, people with pain problems are often forced to take a break from doing their household chores because of their pain. They might delay resuming their chore, eventually needing longer time to finish it. We investigated how activity interruptions by pain influence the pattern of subsequent activity performance. We expected that when an activity is interrupted by pain (compared to non-pain), people spend longer time away from the activity, need longer time to complete it, and are less motivated to perform it. Methods: Sixty healthy volunteers performed an ongoing task that required them to make joystick movements in different directions according to a specific rule. Occasionally, participants received either a painful electrocutaneous stimulus or a non-painful and non-aversive auditory stimulus (between-subjects) as an interruption cue. The interruption cue was followed by the temporary suspension of the ongoing task and the initiation of a different activity (interruption task). The latter required the categorization of cards and had a maximum duration, but participants could also stop it earlier by pressing a button. We measured time away from the (interrupted) ongoing task, total time to complete the ongoing task (including the interruptions) and self-reported motivation to perform both the ongoing as well as the interruption task. Results: Groups did not differ in the time away from the ongoing task, total time to complete the ongoing task, or self-reported motivation to perform the two tasks. Conclusions: Activity interruptions by pain did not impair the pattern of activity performance more than activity interruptions by non-pain. Potential explanations and suggestions for future research are discussed.