Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium.
PLoS One. 2011;6(6):e20926. doi: 10.1371/journal.pone.0020926. Epub 2011 Jun 7.
Because pain often signals the occurrence of potential tissue damage, a nociceptive stimulus has the capacity to involuntarily capture attention and take priority over other sensory inputs. Whether distraction by nociception actually occurs may depend upon the cognitive characteristics of the ongoing activities. The present study tested the role of working memory in controlling the attentional capture by nociception.
Participants performed visual discrimination and matching tasks in which visual targets were shortly preceded by a tactile distracter. The two tasks were chosen because of the different effects the involvement of working memory produces on performance, in order to dissociate the specific role of working memory in the control of attention from the effect of general resource demands. Occasionally (i.e. 17% of the trials), tactile distracters were replaced by a novel nociceptive stimulus in order to distract participants from the visual tasks. Indeed, in the control conditions (no working memory), reaction times to visual targets were increased when the target was preceded by a novel nociceptive distracter as compared to the target preceded by a frequent tactile distracter, suggesting attentional capture by the novel nociceptive stimulus. However, when the task required an active rehearsal of the visual target in working memory, the novel nociceptive stimulus no longer induced a lengthening of reaction times to visual targets, indicating a reduction of the distraction produced by the novel nociceptive stimulus. This effect was independent of the overall task demands.
Loading working memory with pain-unrelated information may reduce the ability of nociceptive input to involuntarily capture attention, and shields cognitive processing from nociceptive distraction. An efficient control of attention over pain is best guaranteed by the ability to maintain active goal priorities during achievement of cognitive activities and to keep pain-related information out of task settings.
由于疼痛通常预示着潜在组织损伤的发生，伤害性刺激具有无意识地吸引注意力并优先于其他感觉输入的能力。伤害性刺激是否会分散注意力可能取决于正在进行的活动的认知特征。本研究测试了工作记忆在控制伤害性刺激引起的注意力捕获中的作用。
参与者执行视觉辨别和匹配任务，其中视觉目标短暂地被触觉干扰物所先行。选择这两个任务是因为工作记忆的参与对表现产生不同的影响，以便将工作记忆在注意力控制中的特定作用与一般资源需求的影响区分开来。偶尔（即 17%的试验），触觉干扰物会被新的伤害性刺激取代，以分散参与者对视觉任务的注意力。事实上，在对照条件下（没有工作记忆），与目标前有常见触觉干扰物相比，当目标前有新的伤害性干扰物时，对视觉目标的反应时间会增加，这表明新的伤害性刺激引起了注意力的捕获。然而，当任务需要在工作记忆中主动复述视觉目标时，新的伤害性刺激不再导致对视觉目标的反应时间延长，表明新的伤害性刺激产生的干扰减少。这种效果与整体任务需求无关。
用与疼痛无关的信息加载工作记忆可能会降低伤害性输入无意识地吸引注意力的能力，并保护认知处理免受疼痛干扰。通过在进行认知活动时保持积极的目标优先级并将与疼痛相关的信息排除在任务设置之外，可以最好地保证对疼痛的有效注意力控制。
