Pain and Attention: A Discussion of Two Studies

Abstract

In this issue of The Journal of Pain, 2 studies address the question of how attention and pain are intertwined. Vancleef et al 2 showed that administration of a pain stimulus caused task performance deterioration. In contrast, Veldhuijzen et al 3 demonstrated that administration of pain did not cause deficits in attentional task performance.Both studies assessed the disruptive effect of pain on attention; however, they used different approaches to address this issue. Two of these different approaches can be considered possible candidates to account for the different outcomes, ie, the anticipatory fearfulness or experienced threat value of the pain stimulus, and the way experimental pain was administered.One of the most important differences between the studies was the modulation of anticipatory fearfulness to the pain stimulus. In the study of Vancleef et al, 2 participants were instructed before the start of the experiment that a pain stimulus would be applied. Further, the authors told the participants that this stimulus would directly stimulate the pain fibers to further increase the perceived threat value of the pain stimulus. Although the subjects were instructed to ignore the pain stimuli and to concentrate on performing the task, task performance deteriorated when the pain stimulus was simultaneously applied with the task. In contrast, in the study of Veldhuijzen et al, 3 participants were not informed that the stimulus applied would be painful, and therefore, the participants did not experience anticipatory fear toward the pain stimulus. The results of this study demonstrated that when participants were not expecting a painful stimulus, and therefore the pain stimulus had no threat value, no disruptive effects of pain on attention were found. In fact, the intensity of pain was experienced less in the most difficult task condition, suggesting that performing a more demanding task may distract attention from pain perception when the painful stimulus is not regarded as a threat.The results of these 2 studies together are in line with previous studies suggesting that several factors may extend the attentional demand of pain.

Performance-dependent inhibition of pain by an executive working memory task

“…Even if pain and task processing engage overlapping executive resources, if this engagement does not overlap in time, participants would be able to switch attention back and forth between pain and cognitive demand, allowing both to be fully processed [24; 72; 73]. Thus, a fourth choice we made was to combine continuous thermal pain with a speeded n-back task that placed relatively continuous demand on executive working memory.…”