Functional connectivity of visual cortex in the blind follows retinotopic organization principles.
Functional connectivity of visual cortex in the blind follows retinotopic organization principles.
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视觉皮层在盲人中的功能连通性遵循视网膜组织原理。
DOI：
10.1093/brain/awv083
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发表时间：
2015-06
期刊：
影响因子：
--
通讯作者：
Amedi A
中科院分区：
文献类型：
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作者：
Striem-Amit E;Ovadia-Caro S;Caramazza A;Margulies DS;Villringer A;Amedi A
虽然早期视觉经验对于视觉皮层的正常发育至关重要，但Striem-Amit等人表明，即使在先天失明的个体中，视网膜定位映射的潜在连接结构也被保留下来。这一基本的组织原则独立于视觉输入而出现，并持续存在，尽管终身经验依赖的可塑性。虽然早期视觉经验对于视觉皮层的正常发育至关重要，但Striem-Amit等人表明，即使在先天失明的个体中，视网膜定位映射的潜在连接结构也被保留下来。这一基本的组织原则独立于视觉输入而出现，并持续存在，尽管终身经验依赖的可塑性。在发育的关键时期，视觉输入对视觉皮层的基本地形图的出现至关重要吗？这种结构会在终生失明的过程中保留下来吗？或者它会因为基于使用的可塑性重组而消失吗？我们使用功能连接磁共振成像的基础上固有的血氧水平依赖性的波动，以调查是否显着的痕迹地形图映射的视觉场景的视网膜组织的形式，可以发现在先天性失明的成年人。一组11名完全和先天性失明的受试者和18名视力正常的对照进行了研究。盲人表现出一个完整的功能连接网络结构组织的三个主要retinotopic映射轴：偏心率（中心-周边），偏侧性（左-右），海拔（上-下）整个retinotopic皮层延伸到高层次的腹侧和背侧流，包括特征偏心偏见的脸和房子的选择性领域。基于功能连接的地形组织在视觉皮层是无法区分的正常视力的视网膜功能连接结构所示的聚类分析，并发现即使在参与者没有一个典型的视网膜发育在子宫内（小眼）。虽然视觉皮层的内部结构组织惊人地相似，但与视力正常的人相比，盲人在与其他（非视觉）大脑区域的功能连接方面表现出深刻的差异，这是特定于V1部分的。中央V1更多地与语言区相连，而周边V1则与空间注意和控制网络相连。这些研究结果表明，目前的帐户的关键时期和经验依赖的发展，应重新审视，即使是初级感觉区，在连接的基础上，视觉皮层大规模的地形组织可以发展没有任何视觉经验，并保留通过终身的经验依赖的可塑性。此外，视网膜的分工，如通常代表中央凹和周边的视觉皮层区域之间的分工，也形成了盲人地形独特的可塑性变化的基础。
Although early visual experience is essential for the proper development of visual cortex, Striem-Amit et al. show that the underlying connectivity structure of retinotopic mapping is retained even in congenitally blind individuals. This basic organisational principle emerges independently of visual input and persists despite lifelong experience-dependent plasticity. Although early visual experience is essential for the proper development of visual cortex, Striem-Amit et al. show that the underlying connectivity structure of retinotopic mapping is retained even in congenitally blind individuals. This basic organisational principle emerges independently of visual input and persists despite lifelong experience-dependent plasticity. Is visual input during critical periods of development crucial for the emergence of the fundamental topographical mapping of the visual cortex? And would this structure be retained throughout life-long blindness or would it fade as a result of plastic, use-based reorganization? We used functional connectivity magnetic resonance imaging based on intrinsic blood oxygen level-dependent fluctuations to investigate whether significant traces of topographical mapping of the visual scene in the form of retinotopic organization, could be found in congenitally blind adults. A group of 11 fully and congenitally blind subjects and 18 sighted controls were studied. The blind demonstrated an intact functional connectivity network structural organization of the three main retinotopic mapping axes: eccentricity (centre-periphery), laterality (left-right), and elevation (upper-lower) throughout the retinotopic cortex extending to high-level ventral and dorsal streams, including characteristic eccentricity biases in face- and house-selective areas. Functional connectivity-based topographic organization in the visual cortex was indistinguishable from the normally sighted retinotopic functional connectivity structure as indicated by clustering analysis, and was found even in participants who did not have a typical retinal development in utero (microphthalmics). While the internal structural organization of the visual cortex was strikingly similar, the blind exhibited profound differences in functional connectivity to other (non-visual) brain regions as compared to the sighted, which were specific to portions of V1. Central V1 was more connected to language areas but peripheral V1 to spatial attention and control networks. These findings suggest that current accounts of critical periods and experience-dependent development should be revisited even for primary sensory areas, in that the connectivity basis for visual cortex large-scale topographical organization can develop without any visual experience and be retained through life-long experience-dependent plasticity. Furthermore, retinotopic divisions of labour, such as that between the visual cortex regions normally representing the fovea and periphery, also form the basis for topographically-unique plastic changes in the blind.