生物谷导读：双手交叉这种姿势多代表社交中的防守型姿态，而现在科学家又发现了它的一个新用途——减轻疼痛。
图片来源：ALAMY
据新华社电 英国伦敦大学学院科学家发现，双臂交叉放于胸前的姿势不仅舒服，而且可以在某种程度上减轻痛感。
研究中，研究者用激光在8名志愿者的手臂上制造“纯痛感”，而后用脑电图监测志愿者的痛感变化。“纯痛感”指不接触型疼痛，一般持续时间短。在这项研究中，研究者用激光灼烧志愿者手臂皮肤，每次时间仅4毫秒。结果发现，当志愿者双臂交叉放于胸前时，这种痛感奇妙地减轻了。
结论已经试验证实，但原因还没有定论。英国伦敦大学学院生理学、药理学和神经学系教授詹多梅尼科·扬内蒂认为，双臂交叉的姿势致使大脑中“两幅图产生混乱”。这两幅图分别是自身人体图和外部空间图。
路透社20日援引扬内蒂的话报道，通常情况下，人类用左手感知左边的世界，用右手感知右边的世界，因此，控制左半身的大脑通常会在激活时调用左边空间的感知图，控制右半身的大脑在激活时调用右边空间的感知图。
“而你把双臂交叉时，这些大脑图便乱了套，”扬内蒂说，从而使大脑处理传递信息的能力变弱，因此对痛感的感知会迟钝和削弱。（生物谷Bioon.com）
生物谷提供文献索引摘要：
PAIN Volume 152, Issue 6 , Pages 1418-1423, June 2011
The analgesic effect of crossing the arms
A. Gallace, D.M.E. Torta,G.L. Moseley,G.D. Iannetti
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.
链接：http://www.painjournalonline.com/article/S0304-3959(11)00138-2/abstract
