Centre for Pain Research, University of Bath, Bath, Somerset, United Kingdom.
Department of Psychology, University of Bath, Bath, Somerset, United Kingdom.
PLoS One. 2019 May 16;14(5):e0210045. doi: 10.1371/journal.pone.0210045. eCollection 2019.
Representations of the body and peripersonal space can be distorted for people with some chronic pain conditions. Experimental pain induction can give rise to similar, but transient distortions in healthy individuals. However, spatial and bodily representations are dynamic, and constantly update as we interact with objects in our environment. It is unclear whether induced pain disrupts the mechanisms involved in updating these representations. In the present study, we sought to investigate the effect of induced pain on the updating of peripersonal space and body representations during and following tool-use. We compared performance under three conditions (pain, active placebo, neutral) on a visuotactile crossmodal congruency task and a tactile distance judgement task to measure updating of peripersonal space and body representations, respectively. Consistent with previous findings, the difference in crossmodal interference from visual distractors in the same compared to opposite visual field to the tactile target was less when tools were crossed than uncrossed. This suggests an extension of peripersonal space to incorporate the tips of the tools. Also consistent with previous findings, estimates of the felt tactile distance judgements decreased after active tool-use. In contrast to our predictions, however, we found no evidence that pain interfered with performance on either task when compared to the control conditions. Our findings suggest that the updating of peripersonal space and body representations is not disrupted by induced pain. That is, experiencing acute pain does not give rise to distorted representations of the body and peripersonal space that can be present in people with chronic pain conditions.
身体和近体空间的表象可能会因某些慢性疼痛病症的患者而扭曲。实验性疼痛诱导会导致健康个体产生类似但短暂的扭曲。然而,空间和身体表象是动态的,并且随着我们与环境中的物体互动而不断更新。目前尚不清楚诱导性疼痛是否会破坏这些表象更新所涉及的机制。在本研究中,我们试图调查诱导性疼痛对工具使用期间和之后近体空间和身体表象更新的影响。我们在视觉触觉跨模态一致性任务和触觉距离判断任务中比较了三种条件(疼痛、主动安慰剂、中性)下的表现,以分别测量近体空间和身体表象的更新。与先前的发现一致,当工具交叉而不是不交叉时,来自同一视觉场到触觉目标的视觉干扰与来自对侧视觉场的视觉干扰之间的跨模态干扰差异较小。这表明近体空间扩展到包括工具的尖端。同样与先前的发现一致,在主动使用工具后,对触觉距离判断的感觉估计减少了。然而,与我们的预测相反,与对照条件相比,我们没有发现疼痛在这两个任务上的表现受到干扰的证据。我们的发现表明,近体空间和身体表象的更新不会因诱导性疼痛而受到干扰。也就是说,经历急性疼痛不会导致身体和近体空间的扭曲表象,而这些表象可能存在于患有慢性疼痛病症的患者中。