Department of Psychology, University of Milano-Bicocca, Italy Department of Neuroscience, Physiology and Pharmacology, University College London, UK Department of Psychology, University of Turin, Italy The Sansom Institute for Health Research, University of South Australia, Adelaide, and Neuroscience Research Australia, Sydney, Australia.
Pain. 2011 Jun;152(6):1418-1423. doi: 10.1016/j.pain.2011.02.029. Epub 2011 Mar 26.
The ability to determine precisely the location of sensory stimuli is fundamental to how we interact with the world; indeed, to our survival. Crossing the hands over the body midline impairs this ability to localize tactile stimuli. We hypothesized that crossing the arms would modulate the intensity of pain evoked by noxious stimulation of the hand. In two separate experiments, we show (1) that the intensity of both laser-evoked painful sensations and electrically-evoked nonpainful sensations were decreased when the arms were crossed over the midline, and (2) that these effects were associated with changes in the multimodal cortical processing of somatosensory information. Critically, there was no change in the somatosensory-specific cortical processing of somatosensory information. Besides studies showing relief of phantom limb pain using mirrors, this is the first evidence that impeding the processes by which the brain localises a noxious stimulus can reduce pain, and that this effect reflects modulation of multimodal neural activities. By showing that the neural mechanisms by which pain emerges from nociception represent a possible target for analgesia, we raise the possibility of novel approaches to the treatment of painful clinical conditions. Crossing the arms over the midline impairs multimodal processing of somatosensory stimuli and induces significant analgesia to noxious hand stimulation.
准确确定感觉刺激位置的能力是我们与世界互动的基础；实际上，这对我们的生存至关重要。双手越过身体中线会损害这种定位触觉刺激的能力。我们假设双臂交叉会调节手部受到有害刺激时引起的疼痛强度。在两个单独的实验中，我们表明：(1) 当手臂越过中线时，激光引起的疼痛感觉和电引起的无痛感觉的强度都会降低；(2) 这些效应与躯体感觉信息的多模态皮质处理的变化有关。至关重要的是，躯体感觉信息的躯体感觉特异性皮质处理没有变化。除了使用镜子缓解幻肢痛的研究外，这是第一个证明阻碍大脑定位有害刺激的过程可以减轻疼痛的证据，并且这种效应反映了多模态神经活动的调节。通过表明疼痛从伤害感受中产生的神经机制可能成为镇痛的目标，我们提出了治疗疼痛临床病症的新方法的可能性。双臂越过中线会损害躯体感觉刺激的多模态处理，并对手部有害刺激引起的明显镇痛。
