Functional specialization for auditory-spatial processing in the occipital cortex of congenitally blind humans
Functional specialization for auditory-spatial processing in the occipital cortex of congenitally blind humans
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DOI：
10.1073/pnas.1013928108
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发表时间：
2011-03-15
影响因子：
11.1
通讯作者：
Lepore, Franco
中科院分区：
文献类型：
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作者：
Collignon, Olivier;Vandewalle, Gilles;Lepore, Franco
先天性失明（CB）的研究是一个独特的机会，探索经验依赖性可塑性的感觉区域剥夺了其自然输入，因为出生。尽管一些研究表明CB的枕区参与非视觉处理，但在有视力的人（SI）中观察到的视觉皮质的功能组织是否在盲人的重新布线的枕区中得以维持，直到最近才得到研究。在目前的功能性MRI研究中，我们比较了CB和SI处理两个域中携带信息的声音的空间或音高特性的大脑活动（即，在两个任务中使用相同的声音），使用专门设计用于调节性能水平的自适应程序。除了显示大量招聘的枕叶皮层的声音处理CB，我们还表明，听觉空间处理主要招聘右楔叶和右枕中回，两个地区的背枕叶流已知参与视觉空间/运动处理SI。此外，功能连接分析显示，这些重组的枕叶区域是广泛的大脑网络的一部分，包括已知的视听空间能力（即，顶内沟、上级额回）。我们的结论是，右枕背流的某些区域不需要视觉经验来发展空间信息处理的专业化，并在功能上整合到一个预先存在的大脑网络中，专门用于这种能力。
The study of the congenitally blind (CB) represents a unique opportunity to explore experience-dependant plasticity in a sensory region deprived of its natural inputs since birth. Although several studies have shown occipital regions of CB to be involved in nonvisual processing, whether the functional organization of the visual cortex observed in sighted individuals (SI) is maintained in the rewired occipital regions of the blind has only been recently investigated. In the present functional MRI study, we compared the brain activity of CB and SI processing either the spatial or the pitch properties of sounds carrying information in both domains (i.e., the same sounds were used in both tasks), using an adaptive procedure specifically designed to adjust for performance level. In addition to showing a substantial recruitment of the occipital cortex for sound processing in CB, we also demonstrate that auditory-spatial processing mainly recruits the right cuneus and the right middle occipital gyrus, two regions of the dorsal occipital stream known to be involved in visuospatial/motion processing in SI. Moreover, functional connectivity analyses revealed that these reorganized occipital regions are part of an extensive brain network including regions known to underlie audiovisual spatial abilities (i.e., intraparietal sulcus, superior frontal gyrus). We conclude that some regions of the right dorsal occipital stream do not require visual experience to develop a specialization for the processing of spatial information and to be functionally integrated in a preexisting brain network dedicated to this ability.