Papers of the Week

Pain-related avoidance is adaptive when there is bodily threat, but when it generalizes to safe movements/situations, it may become disabling. Both subclinical anxiety -a vulnerability marker for chronic pain -and chronic pain are associated with excessive fear generalization to safe stimuli/situations. Previous research focused mainly on passive fear correlates (psychophysiological arousal and self-reports) leaving avoidance behavior poorly understood. Therefore, we tested whether high-anxious individuals generalize their pain-related avoidance behavior more to novel, safe contexts than low-anxious people. In a robotic-arm reaching task, both groups (low vs. high trait anxiety) performed one of three movements to reach a target. In the threat context (black background), a painful stimulus could be partly/completely prevented by performing more effortful trajectories (longer and more force needed); in the safe context (white background), no pain occurred. Generalization of avoidance was tested in two novel contexts (light/dark grey backgrounds). We assessed pain-expectancy, pain-related fear, and startle eyeblink responses for all trajectories, and avoidance behavior (i.e., maximal deviation from shortest trajectory). Results indicated that differential fear and expectancy selectively generalized to the novel context resembling the original threat context in both groups. Interestingly and in contrast with the verbal reports, high-anxious participants avoided more in the novel context resembling the original safe context, but not in the one resembling the threat context. No generalization emerged in the startle data. Because excessive pain-related avoidance specifically may cause withdrawal from daily life activities, these findings suggest that high-anxious individuals may be vulnerable to develop chronic pain disability. PERSPECTIVE: This paper shows that high-anxious people do not overgeneralize pain-related fear and pain-expectancy learned in a threat context more to novel, safe contexts than low-anxious individuals, but that they do avoid more in those contexts. These findings suggest that high-anxious individuals may be vulnerable to develop chronic pain disability.