2016_Krishnan_VPS_eLife

Associated publication: Krishnan, A., Woo, C. W., Chang, L. J., Ruzic, L., Gu, X., Lopez-Sola, M., ... & Wager, T. D. (2016). Somatic and vicarious pain are represented by dissociable multivariate brain patterns. Elife, 5, e15166.Abstract: Understanding how humans represent others’ pain is critical for understanding pro-social behavior. ‘Shared experience’ theories propose common brain representations for somatic and vicarious pain, but other evidence suggests that specialized circuits are required to experience others’ suffering. Combining functional neuroimaging with multivariate pattern analyses, we identified dissociable patterns that predicted somatic (high versus low: 100%) and vicarious (high versus low: 100%) pain intensity in out-of-sample individuals. Critically, each pattern was at chance in predicting the other experience, demonstrating separate modifiability of both patterns. Somatotopy (upper versus lower limb: 93% accuracy for both conditions) was also distinct, located in somatosensory versus mentalizing-related circuits for somatic and vicarious pain, respectively. Two additional studies demonstrated the generalizability of the somatic pain pattern (which was originally developed on thermal pain) to mechanical and electrical pain, and also demonstrated the replicability of the somatic/vicarious dissociation. These findings suggest possible mechanisms underlying limitations in feeling others’ pain, and present new, more specific, brain targets for studying pain empathy.关联发表文献：Krishnan, A.、Woo, C. W.、Chang, L. J.、Ruzic, L.、Gu, X.、Lopez-Sola, M. 等（2016）。《躯体疼痛与替代性疼痛由可分离的多变量脑模式表征》（Somatic and vicarious pain are represented by dissociable multivariate brain patterns），发表于*Elife*，第5卷，e15166。 摘要：阐明人类如何表征他人的疼痛，是理解亲社会行为的关键所在。“共享体验”理论提出，躯体疼痛（somatic pain）与替代性疼痛（vicarious pain）拥有共同的脑表征，但其他研究证据表明，体验他人的痛苦需要依赖特异性神经环路。本研究结合功能神经成像（functional neuroimaging）与多变量模式分析（multivariate pattern analyses）技术，在外样本个体（out-of-sample individuals）中识别出可分离的脑模式，该模式能够分别预测躯体疼痛（高vs低强度：准确率100%）与替代性疼痛（高vs低强度：准确率100%）的强度。尤为关键的是，任一模式在预测另一种类型的疼痛体验时，准确率仅处于随机猜测水平，这证实两类脑模式各自具备独立的可修改性。躯体拓扑映射（somatotopy，上肢vs下肢：两种条件下准确率均为93%）同样存在显著差异：躯体疼痛的相关脑区位于躯体感觉环路，而替代性疼痛则关联心理化（mentalizing）相关环路。后续两项额外研究证实，最初基于热痛（thermal pain）开发的躯体疼痛模式，可推广至机械痛（mechanical pain）与电痛（electrical pain），同时验证了躯体/替代性疼痛分离现象的可重复性。本研究结果揭示了人类共情他人疼痛时存在感知局限的潜在机制，并为疼痛共情（pain empathy）研究提供了全新且更具特异性的脑靶点。