Different pain types may be encoded in different brain circuits. Here, we examine similarities and differences in brain processing of visceral and somatic pain. We analyze data from seven fMRI studies (N = 165) and five types of pain and discomfort (esophageal, gastric, and rectal distension, cutaneous thermal stimulation, and vulvar pressure) to establish and validate generalizable pain representations. We first evaluate an established multivariate brain measure, the Neurologic Pain Signature (NPS), as a common nociceptive pain system across pain types. Then, we develop a multivariate classifier to distinguish visceral from somatic pain. The NPS responds robustly in 98% of participants across pain types, correlates with perceived intensity of visceral pain and discomfort, and shows specificity to pain when compared with cognitive and affective conditions from twelve additional studies (N = 180). Pre-defined signatures for non-pain negative affect do not respond to visceral pain. The visceral versus the somatic classifier reliably distinguishes somatic (thermal) from visceral (rectal) stimulation in both cross-validation and independent cohorts. Other pain types reflect mixtures of somatic and visceral patterns. These results validate the NPS as measuring a common core nociceptive pain system across pain types, and provide a new classifier for visceral versus somatic pain.

不同的疼痛类型可能编码在不同的大脑回路中。在这里，我们检查内脏和躯体疼痛的大脑处理的异同。我们分析了七项 fMRI 研究的数据（N = 165) 和五种类型的疼痛和不适（食道、胃和直肠膨胀、皮肤热刺激和外阴压力），以建立和验证可概括的疼痛表现。我们首先评估已建立的多变量大脑测量，神经疼痛特征 (NPS)，作为跨疼痛类型的常见伤害性疼痛系统。然后，我们开发了一个多变量分类器来区分内脏痛和躯体痛。NPS 在 98% 的不同疼痛类型的参与者中反应强烈，与感知到的内脏疼痛和不适强度相关，并且与来自 12 项其他研究的认知和情感状况相比显示出对疼痛的特异性（N = 180）。非疼痛负面影响的预定义特征对内脏疼痛没有反应。内脏与躯体分类器在交叉验证和独立队列中可靠地区分躯体（热）刺激和内脏（直肠）刺激。其他疼痛类型反映了躯体和内脏模式的混合。这些结果验证了 NPS 可以测量跨疼痛类型的共同核心伤害性疼痛系统，并为内脏痛与躯体痛提供了一个新的分类器。