Research Center of Neurology, Moscow, Russia.
M.V. Lomonosov Moscow State University, Faculty of Psychology, Moscow, Russia.
Cortex. 2021 Nov;144:185-197. doi: 10.1016/j.cortex.2021.08.009. Epub 2021 Sep 28.
Although the neural systems supporting interoception have been outlined in general, the exact processes underlying the integration of visceral signals still await research. Based on the predictive coding concept, we aimed to reveal the neural networks responsible for the bottom-up (stimulus-dependent) and top-down (model-dependent) processing of interoceptive information. In a study of 30 female participants, we utilized two classical body perception experiments-the rubber hand illusion and a heartbeat detection task (cardioception), with the latter being implemented in fMRI settings. We interpreted a stronger rubber hand illusion, as measured by higher proprioceptive drift, as a tendency to rely on actual sensory experience, i.e., bottom-up processing, while lower proprioceptive drift served as an indicator of the prevalence of top-down, model-based influences. To reveal the bottom-up and top-down processes in cardioception, we performed a seed-based connectivity analysis of the heartbeat detection task, using as seeds the areas with known roles in sensory integration and entering proprioceptive drift as a covariate. The results revealed a left thalamus-dependent network positively associated with proprioceptive drift (bottom-up processing) and a left amygdala-dependent network negatively associated with drift (top-down processing). Bottom-up processing was related to thalamic connectivity with the left frontal operculum and anterior insula, anterior cingulate cortex, hypothalamus, right planum polare and right inferior frontal gyrus. Top-down processing was related to amygdalar connectivity with the rostral prefrontal cortex and an area involving the left frontal opercular and anterior insular cortex, with the latter area being an intersection of the two networks. Thus, we revealed the neural mechanisms underlying the integration of interoceptive information through the interaction between the current sensory experience and internal models.
尽管支持内感受的神经系统已被大致勾勒出来，但内脏信号整合的确切过程仍有待研究。基于预测编码概念，我们旨在揭示负责内感受信息的自下而上（依赖于刺激）和自上而下（依赖于模型）加工的神经网络。在一项针对 30 名女性参与者的研究中，我们利用了两个经典的身体感知实验——橡胶手错觉和心跳检测任务（心感知），后者在 fMRI 环境中进行。我们将更高的本体感觉漂移解释为更倾向于依赖实际的感官体验，即自下而上的加工，而较低的本体感觉漂移则作为基于模型的自上而下影响的指标，以此来衡量更强的橡胶手错觉。为了揭示心感知中的自下而上和自上而下的过程，我们对心跳检测任务进行了基于种子的连通性分析，使用已知在感觉整合中起作用的区域作为种子，并将本体感觉漂移作为协变量。结果显示，一个与本体感觉漂移（自下而上的加工）呈正相关的左侧丘脑依赖性网络，以及一个与漂移呈负相关的左侧杏仁核依赖性网络（自上而下的加工）。自下而上的加工与丘脑与左侧额下回和前岛叶、前扣带皮质、下丘脑、右侧极平面和右侧额下回的连通性有关。自上而下的加工与杏仁核与额前皮质和包括左侧额下回和前岛叶的区域的连通性有关，后一区域是两个网络的交点。因此，我们通过当前感觉体验与内部模型之间的相互作用，揭示了内感受信息整合的神经机制。
