García-Cordero Indira, Esteves Sol, Mikulan Ezequiel P, Hesse Eugenia, Baglivo Fabricio H, Silva Walter, García María Del Carmen, Vaucheret Esteban, Ciraolo Carlos, García Hernando S, Adolfi Federico, Pietto Marcos, Herrera Eduar, Legaz Agustina, Manes Facundo, García Adolfo M, Sigman Mariano, Bekinschtein Tristán A, Ibáñez Agustín, Sedeño Lucas
Laboratory of Experimental Psychology and Neuroscience, Institute of Cognitive and Translational Neuroscience, INECO Foundation, Favaloro UniversityBuenos Aires, Argentina.
National Scientific and Technical Research CouncilBuenos Aires, Argentina.
Front Neurosci. 2017 Jul 19;11:411. doi: 10.3389/fnins.2017.00411. eCollection 2017.
Interoception, the monitoring of visceral signals, is often presumed to engage attentional mechanisms specifically devoted to inner bodily sensing. In fact, most standardized interoceptive tasks require directing attention to internal signals. However, most studies in the field have failed to compare attentional modulations between internally- and externally-driven processes, thus probing blind to the specificity of the former. Here we address this issue through a multidimensional approach combining behavioral measures, analyses of event-related potentials and functional connectivity via high-density electroencephalography, and intracranial recordings. In Study 1, 50 healthy volunteers performed a heartbeat detection task as we recorded modulations of the heartbeat-evoked potential (HEP) in three conditions: exteroception, basal interoception (also termed interoceptive accuracy), and post-feedback interoception (sometimes called interoceptive learning). In Study 2, to evaluate whether key interoceptive areas (posterior insula, inferior frontal gyrus, amygdala, and somatosensory cortex) were differentially modulated by externally- and internally-driven processes, we analyzed human intracranial recordings with depth electrodes in these regions. This unique technique provides a very fine grained spatio-temporal resolution compared to other techniques, such as EEG or fMRI. We found that both interoceptive conditions in Study 1 yielded greater HEP amplitudes than the exteroceptive one. In addition, connectivity analysis showed that post-feedback interoception, relative to basal interoception, involved enhanced long-distance connections linking frontal and posterior regions. Moreover, results from Study 2 showed a differentiation between oscillations during basal interoception (broadband: 35-110 Hz) and exteroception (1-35 Hz) in the insula, the amygdala, the somatosensory cortex, and the inferior frontal gyrus. In sum, this work provides convergent evidence for the specificity and dynamics of attentional mechanisms involved in interoception.
内感受，即对内脏信号的监测，通常被认为会启动专门用于内部身体感知的注意机制。事实上，大多数标准化的内感受任务都需要将注意力导向内部信号。然而，该领域的大多数研究都未能比较内部驱动和外部驱动过程之间的注意调制，因此对前者的特异性研究不足。在这里，我们通过一种多维度方法来解决这个问题，该方法结合了行为测量、事件相关电位分析以及通过高密度脑电图和颅内记录进行的功能连接分析。在研究1中，50名健康志愿者执行了一项心跳检测任务，同时我们记录了在三种情况下心跳诱发电位（HEP）的调制：外感受、基础内感受（也称为内感受准确性）和反馈后内感受（有时称为内感受学习）。在研究2中，为了评估关键内感受区域（后岛叶、额下回、杏仁核和体感皮层）是否受到外部和内部驱动过程的不同调制，我们分析了在这些区域使用深度电极进行的人类颅内记录。与脑电图或功能磁共振成像等其他技术相比，这种独特的技术提供了非常精细的时空分辨率。我们发现，研究1中的两种内感受条件产生的HEP振幅均大于外感受条件。此外，连接性分析表明，相对于基础内感受，反馈后内感受涉及额叶和后部区域之间增强的长距离连接。此外，研究2的结果表明，在基础内感受（宽带：35 - 110赫兹）和外感受（1 - 35赫兹）期间，岛叶、杏仁核、体感皮层和额下回的振荡存在差异。总之，这项工作为内感受中涉及的注意机制的特异性和动态性提供了一致的证据。
