Although clinical neuroscience and the neuroscience of consciousness have long sought mechanistic explanations of tactile-awareness disorders, mechanistic insights are rare, mainly because of the difficulty of depicting the fine-grained neural dynamics underlying somatosensory processes. Here, we combined the stereo-EEG responses to somatosensory stimulation with the lesion mapping of patients with a tactile-awareness disorder, namely tactile extinction. Whereas stereo-EEG responses present different temporal patterns, including early/phasic and long-lasting/tonic activities, tactile-extinction lesion mapping co-localizes only with the latter. Overlaps are limited to the posterior part of the perisylvian regions, suggesting that tonic activities may play a role in sustaining tactile awareness. To assess this hypothesis further, we correlated the prevalence of tonic responses with the tactile-extinction lesion mapping, showing that they follow the same topographical gradient. Finally, in parallel with the notion that visuotactile stimulation improves detection in tactile-extinction patients, we demonstrated an enhancement of tonic responses to visuotactile stimuli, with a strong voxel-wise correlation with the lesion mapping. The combination of these results establishes tonic responses in the parietal operculum as the ideal neural correlate of tactile awareness.

中文翻译：

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强直的体感反应和触觉意识的缺陷在顶叶鳃盖集中

尽管临床神经科学和意识神经科学长期以来一直在寻求对触觉意识障碍的机械解释，但机械方面的见解很少见，主要是因为难以描述体感过程背后的细粒度神经动力学。在这里，我们将立体脑电图对体感刺激的反应与触觉意识障碍（即触觉消退）患者的病灶映射相结合。虽然立体脑电图反应呈现不同的时间模式，包括早期/阶段性和持久/强直活动，但触觉消失病变映射仅与后者共同定位。重叠仅限于外侧裂区的后部，这表明补品活动可能在维持触觉意识方面发挥作用。为了进一步评估这个假设，我们将强直反应的普遍性与触觉消失病变映射相关联，表明它们遵循相同的地形梯度。最后，与视觉触觉刺激改善触觉消失患者检测的概念平行，我们证明了对视觉触觉刺激的强直反应增强，与病变映射具有强烈的体素相关性。这些结果的结合确定了顶叶盖中的强直反应，作为触觉感知的理想神经关联。我们证明了对视觉触觉刺激的强直反应增强，与病变映射具有强烈的体素相关性。这些结果的结合确定了顶叶盖中的强直反应，作为触觉感知的理想神经关联。我们证明了对视觉触觉刺激的强直反应增强，与病变映射具有强烈的体素相关性。这些结果的结合确定了顶叶盖中的强直反应，作为触觉感知的理想神经关联。