Institut du Cerveau et de la Moelle épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France.
Service de Neurologie 1, Hôpital de la Pitié Salpêtrière, AP-HP, Paris, France.
Cereb Cortex. 2019 Dec 17;29(11):4725-4742. doi: 10.1093/cercor/bhz006.
In early blind individuals, brain activation by a variety of nonperceptual cognitive tasks extends to the visual cortex, while in the sighted it is restricted to supramodal association areas. We hypothesized that such activation results from the integration of different sectors of the visual cortex into typical task-dependent networks. We tested this hypothesis with fMRI in blind and sighted subjects using tasks assessing speech comprehension, incidental long-term memory and both verbal and nonverbal executive control, in addition to collecting resting-state data. All tasks activated the visual cortex in blind relative to sighted subjects, which enabled its segmentation according to task sensitivity. We then assessed the unique brain-scale functional connectivity of the segmented areas during resting state. Language-related seeds were preferentially connected to frontal and temporal language areas; the seed derived from the executive task was connected to the right dorsal frontoparietal executive network; and the memory-related seed was uniquely connected to mesial frontoparietal areas involved in episodic memory retrieval. Thus, using a broad set of language, executive, and memory tasks in the same subjects, combined with resting state connectivity, we demonstrate the selective integration of different patches of the visual cortex into brain-scale networks with distinct localization, lateralization, and functional roles.
在早期失明者中，各种非感知认知任务引起的大脑激活可扩展到视觉皮层，而在视力正常者中，这种激活仅限于超模态联合区域。我们假设这种激活是由于视觉皮层的不同区域整合到典型的任务相关网络中。我们使用 fMRI 在盲人和视力正常的受试者中进行了测试，这些受试者接受了评估语音理解、偶然长期记忆以及言语和非言语执行控制的任务，此外还收集了静息状态数据。所有任务都激活了盲人的视觉皮层，而在视力正常的受试者中则没有，这使得可以根据任务敏感性对其进行分割。然后，我们评估了静息状态下分割区域的独特大脑尺度功能连接。与语言相关的种子与额颞语言区域优先连接；来自执行任务的种子与右侧背侧额顶执行网络连接；与记忆相关的种子与参与情景记忆检索的中额顶叶区域唯一连接。因此，我们使用同一组受试者中的广泛的语言、执行和记忆任务，结合静息状态连接，证明了不同视觉皮层区域的选择性整合到具有不同定位、偏侧性和功能作用的大脑尺度网络中。
