PDF(Pubmed)
Abstract：
Conflicting evidence points to the contribution of several key nodes of the \'social brain\' to the processing of both discriminatory and affective qualities of interpersonal touch. Whether the primary somatosensory cortex (S1) and the medial prefrontal cortex (mPFC), two brain areas vital for tactile mirroring and affective mentalizing, play a functional role in shared representations of C-tactile (CT) targeted affective touch is still a matter of debate. Here, we used offline continuous theta-burst transcranial magnetic stimulation (cTBS) to mPFC, S1 and vertex (control) prior to participants providing ratings of vicarious touch pleasantness for self and others delivered across several body sites at CT-targeted velocities. We found that S1-cTBS led to a significant increase in touch ratings to the self, with this effect being positively associated to levels of interoceptive awareness. Conversely, mPFC-cTBS reduced pleasantness ratings for touch to another person. These effects were not specific for CT-optimal (slow) stroking velocities, but rather they applied to all types of social touch. Overall, our findings challenge the causal role of the S1 and mPFC in vicarious affective touch and suggest that self- vs other-directed vicarious touch responses might crucially depend on the specific involvement of key social networks in gentle tactile interactions.
摘要：
相互矛盾的证据表明，“社会大脑”的几个关键节点对人际接触的歧视性和情感品质的处理都有贡献。无论是初级体感皮层(S1)还是内侧前额叶皮层(mPFC),对触觉镜像和情感思维至关重要的两个大脑区域，在C触觉（CT）针对性情感触摸的共享表示中发挥功能作用仍然是一个有争议的问题。这里,我们使用离线连续theta脉冲经颅磁刺激（cTBS）对mPFC，S1和顶点（控制），然后参与者以CT目标速度在多个身体部位提供自我和他人的替代触摸愉悦评分。我们发现S1-cTBS导致对自我的接触评分显着增加，这种影响与相互感受的意识水平呈正相关。相反，mPFC-cTBS降低了与他人接触的愉悦等级。这些影响不是CT最佳（缓慢）划动速度所特有的，而是适用于所有类型的社会接触。总的来说,我们的发现挑战了S1和mPFC在替代情感接触中的因果作用，并表明自我与其他方向的替代触摸反应可能关键取决于关键社交网络在温和触觉交互中的具体参与。
