Department of Psychology, University of Rome La Sapienza, Italy.
Eur J Neurosci. 2010 Aug;32(4):677-83. doi: 10.1111/j.1460-9568.2010.07305.x. Epub 2010 Jul 9.
Reading action-related verbs brings about sensorimotor neural activity, suggesting that the linguistic representation of actions impinges upon neural structures largely overlapping with those involved in actual action execution. While studies of direct action observation indicate that motor mirroring is inherently anticipatory, no information is currently available on whether deriving action-related knowledge from language also takes into account the temporal deployment of actions. Using transcranial magnetic stimulation, here we sought to determine whether reading action verbs conjugated in the future induced higher cortico-spinal activity with respect to when the same verbs were conjugated in the past tense. We recorded motor-evoked potentials (MEPs) from relaxed hand and leg muscles of healthy subjects who were reading silently hand- or leg-related action, sensorial (non-somatic) and abstract verbs conjugated either in future or past tense. The amplitude of MEPs recorded from the hand was higher during reading hand-related action verbs conjugated in the future than in the past. No future-related modulation of leg muscles activity was found during reading leg-related action verbs. In a similar vein, no future-related change of hand or leg muscles reactivity was found for abstract or sensorial verbs. These results indicate that the anticipatory mirroring of hand actions may be triggered by linguistic representations and not only by direct action observation.
阅读与动作相关的动词会引起感觉运动神经活动，这表明动作的语言表达会影响到与实际动作执行大部分重叠的神经结构。虽然直接观察动作的研究表明运动镜像具有内在的预测性，但目前还没有信息表明从语言中获得与动作相关的知识是否也考虑到了动作的时间部署。本研究使用经颅磁刺激技术，试图确定阅读未来时态的动作动词是否会引起更高的皮质脊髓活动，而阅读过去时态的相同动词则不会。我们记录了健康受试者在安静地阅读手或腿相关动作、感觉（非躯体）和抽象动词时，手部和腿部放松肌肉的运动诱发电位（MEP）。与过去时态相比，阅读未来时态的手部相关动作动词时，手部记录的 MEP 振幅更高。在阅读腿部相关动作动词时，没有发现与未来时态相关的腿部肌肉活动的调制。同样，对于抽象或感觉动词，没有发现手或腿部肌肉反应的未来相关变化。这些结果表明，手部动作的预测性镜像可能是由语言表达触发的，而不仅仅是通过直接观察动作。
