Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PL, UK.
Department of Experimental Psychology, University of Regensburg, Regensburg, Germany.
Sci Rep. 2018 Aug 10;8(1):12001. doi: 10.1038/s41598-018-30480-z.
The conscious experience of being the author of our own actions is thought to be grounded in pre-reflective and low-level sensorimotor representations of the self as different from the other. It has been suggested that the inferior parietal lobe (IPL) is generally involved in self-other differentiation processes and in providing an explicit sense of action authorship. However, direct evidence for its causal and functional role in distinguishing self-related and other-related sensorimotor representations is lacking. The current study employed theta-burst stimulation (TBS) to condition left IPL's activity before a social version of the rubber hand illusion led participants to illusorily attribute observed finger movements to their own body. We recorded motor evoked potentials to single-pulse transcranial magnetic stimulation over the primary motor cortex (M1) as proxies of action authorship during action observation. The results showed that in a control condition (intermediate TBS over the left IPL) others' actions facilitated whereas self-attributed movements inhibited the motor system. Critically, continuous TBS disrupted this mismatch between self and other representations. This outcome provides direct evidence for the IPL's role in providing fundamental authorship signals for social differentiation in the human action system.
被认为是我们自己行为的作者的有意识体验，其基础是自我与他人不同的前反思性和低水平感觉运动表现。有人认为，下顶叶皮层（IPL）通常参与自我与他人的区分过程，并提供明确的行动作者感。然而，关于其在区分自我相关和他人相关感觉运动表现中的因果和功能作用的直接证据尚缺乏。本研究采用经颅磁刺激（TBS）在前橡胶手错觉的社会版本之前对左侧 IPL 的活动进行条件处理，使参与者将观察到的手指运动错觉地归因于自己的身体。我们记录了初级运动皮层（M1）的单脉冲经颅磁刺激的运动诱发电位，作为在观察动作时动作作者身份的代理。结果表明，在对照条件下（左侧 IPL 中的中等 TBS），他人的动作促进了运动系统，而自我归因的运动则抑制了运动系统。关键的是，连续 TBS 破坏了自我和他人表现之间的这种不匹配。这一结果为 IPL 在人类动作系统中提供基本的作者身份信号以进行社会区分提供了直接证据。
