The central problem the researchers set out to solve is methodological. Although decades of experimental work show that attention shapes pain perception, there has been no established way to capture the individual effect of distraction on chronic pain that accounts for the waxing and waning nature of the condition and for whether observed changes are clinically meaningful. In chronic pain intervention literature, a reduction of at least 30 percent in pain intensity is generally considered clinically meaningful. Averaging pain ratings across a task can obscure the moments when an individual reaches such a threshold, so the team instead built a metric they call pain attenuation during a task, or PAT. The PAT score is calculated as the percent change from a baseline pain rating taken just before a task begins to the retrospective rating given after the task block in which pain attenuation was greatest. Positive scores indicate pain decreased during the task, zero indicates no change, and negative scores indicate pain increased.

To test the metric, the researchers recruited 27 people with chronic pain, most of them living with ankylosing spondylitis, an inflammatory form of spondyloarthritis, and 27 healthy controls, all tested at Toronto Western Hospital. Participants completed three short computerized tasks lasting roughly six minutes each, presented in ascending order of difficulty. The simple task was essentially a tapping exercise: a single card displaying the number 1, 2, or 3 appeared on screen and participants pressed the matching keypad button as quickly and accurately as possible. In the easy and hard tasks, three cards appeared side by side, each filled with repetitions of a single digit. The easy task asked participants to identify the largest digit value, while the hard task required comparing how many digits each card contained and reporting the card with the greatest count. People with chronic pain rated their pain intensity and unpleasantness on 0 to 100 scales just before each task and after each of its three one-minute blocks.

The study’s first notable finding concerned motor performance itself. In the simple task, the chronic pain group had a median reaction time of 421 milliseconds, significantly slower than the healthy controls’ median of 328 milliseconds, and their reaction times were also far more variable, with a median standard deviation of 172 milliseconds versus 88 milliseconds in controls. Both differences were statistically significant with a rank biserial correlation of −0.52. The authors interpret this as evidence of diminished psychomotor ability in chronic pain, consistent with their earlier work showing sluggish reaction times on a Stroop task in people with temporomandibular disorder and inconsistent reaction times in ankylosing spondylitis patients. They caution, however, that the healthy controls were significantly younger on average, and that neuropathic pain symptoms such as burning or electric shock-like sensations, as well as pain affecting the upper extremities, could themselves have slowed and destabilized motor responses.

The difficulty manipulation worked as intended, at least partially. Within the chronic pain group, median reaction times climbed from 421 milliseconds on the simple task to 1,278 milliseconds on the easy task and 1,443 milliseconds on the hard task, with reaction time variability also rising and accuracy falling from a median of 100 percent to 97.2 percent and then 95.7 percent. But the easy and hard tasks did not differ robustly from each other on all three performance metrics, so the team streamlined their main analyses to compare the simple and hard tasks. This detail matters for interpreting what came next, because the two cognitively demanding tasks may not have separated cleanly in the attentional resources they demanded.

The key result emerged from the simple task. There was a significant negative correlation between PAT scores for pain intensity and mean reaction time, with a Spearman’s rho of −0.57 and a p-value of 0.0053 that survived Bonferroni correction for multiple comparisons. In plain terms, people whose reaction times were faster, suggesting deeper engagement with the task, tended to show greater percentage reductions in their chronic pain intensity. No such relationship appeared in the hard task, where the correlation between pain intensity PAT and reaction time was a non-significant rho of −0.22. The authors argue that this dissociation is meaningful: because a distraction effect was captured in the simple task, where engagement tracked pain relief, the absence of any engagement-pain relationship in the hard task suggests the scoring system was likely picking up natural fluctuations of chronic pain there rather than a genuine analgesic effect.

The distribution of PAT scores tells a sobering story about how many people actually benefit. In the simple task, only six of the participants showed a decrease in pain intensity, twelve reported no change, and four experienced an increase; of the six who improved, five crossed the clinically relevant threshold of a 30 percent or greater reduction. In the hard task, four people decreased, thirteen were unchanged, four increased, and not a single participant achieved a clinically relevant reduction in pain intensity. For pain unpleasantness in the simple task, six people decreased, thirteen were unchanged, and one increased, while in the hard task five decreased, eleven were unchanged, and five increased. The authors note this ran counter to their hypothesis that harder, more attentionally demanding tasks would produce stronger effects, and to a body of experimental literature in which demanding tasks reduce the perception of experimentally induced pain in healthy people.

Perhaps the most intriguing exploratory finding involved pain character. Using the painDETECT questionnaire, which scores the likelihood of neuropathic pain from 0 to 38, the researchers compared sub-groups defined by their PAT scores. In the simple task, the positive PAT group had a median painDETECT score of 3.5, the no-change group 7.5, and the group whose pain increased during the task a median of 16, a significant difference with a large effect size. A similar pattern appeared in the hard task. The authors suggest that the spontaneous, paroxysmal, and attention-demanding qualities of neuropathic pain, such as burning and electric shock-like sensations, may capture attention and actually intensify pain perception during task engagement, blocking any distraction benefit. They stress, however, that each sub-group was very small, so these results should be treated as preliminary proof of concept rather than established differences.

Several design limitations temper the conclusions. The tasks were not counterbalanced, so the hard task always came last and fatigue may have degraded performance and any potential analgesia, a possibility the authors link to prior work showing cognitive fatigue reduces both task performance and pain attenuation. Asking participants to rate pain after each block creates a paradoxical attention to pain, since they knew ratings were coming and may have monitored their pain during the task. Motivation, interest, and the value placed on a task, which are known to influence attentional prioritization in healthy people, were not measured. The sample also deliberately included people with low average chronic pain, under 3 out of 10 over the previous four weeks, and such mild pain may simply not have been attention-grabbing enough for distraction to demonstrate an effect. The chronic pain group was also significantly older than the controls, and age is known to slow simple reaction times, although prior work suggests group differences between people in their twenties and thirties are typically not significant.

The authors are careful about what their metric does and does not promise. They conclude that distraction may not be an effective long-term coping strategy for chronic pain, noting that prolonged avoidance approaches can increase distress and suffering, while methods that foster acceptance and psychological flexibility may serve patients better. Yet the finding that an automated, simple task can produce clinically relevant, if short-lived, pain relief in a subset of individuals positions the PAT system as a potentially simple and translatable clinical tool for identifying who might benefit from attention-based pain management. Validation studies with larger and more varied samples, longer tasks that allow more temporal variation in pain, and a wider spectrum of baseline pain intensities are the necessary next steps before the metric can guide personalized chronic pain care.

Subject of Research: A proof-of-concept study of a new scoring metric measuring individual changes in chronic pain during task engagement

Article Title: Pain attenuation during task: a proof-of-concept study for a new scoring metric to capture individual differences in chronic pain changes by task engagement

Article References: Sanmugananthan, V. V., El-Sayed, R., Inman, R. D., & Davis, K. D. (2026). Pain attenuation during task: a proof-of-concept study for a new scoring metric to capture individual differences in chronic pain changes by task engagement. Frontiers in Pain Research, 7, Article 1945745. https://doi.org/10.3389/fpain.2026.1945745

Image Credits: AI Generated

DOI: 10.3389/fpain.2026.1945745

Keywords: chronic pain, distraction, attention, pain attenuation during task, neuropathic pain, painDETECT, reaction time, ankylosing spondylitis, psychomotor performance, pain coping, clinical relevance, proof-of-concept study