The fidelity of the cortical retinotopic map in human amblyopia
The fidelity of the cortical retinotopic map in human amblyopia
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DOI：
10.1111/j.1460-9568.2007.05356.x
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发表时间：
2007-03-01
影响因子：
3.4
通讯作者：
Hess, Robert F.
中科院分区：
文献类型：
--
作者：
Li, Xingfeng;Dumoulin, Serge O.;Hess, Robert F.
为了描述弱视患者功能性皮层组织的保真度，我们对弱视观察者的视觉皮层空间信息如何映射进行了研究。我们评估了弱视眼和同侧注视眼控制的视觉区域的边界是否处于同一位置、不同皮质区域内视网膜专题图的保真度以及不同视觉区域的平均感受野大小。使用功能磁共振成像相位编码视网膜专题图分析重建视觉皮层的功能组织。该方法沿着极坐标系的轴顺序刺激视野中的每个点，从而重建视野在皮层上的表示。我们发现正常人和弱视眼的皮质区域非常相似，固定眼和弱视眼激活之间不同视觉区域的边界位置只有很小的差异。在这些相应的视觉区域内，我们确实发现一些但并非所有弱视患者的视网膜病变异常，这不仅仅是功能反应较差的结果，而且还影响了中央和周边视野区域。对于弱视的全视场表征，发现平均（或集体）感受野大小仅小幅增加，而对于中央视场表征则完全没有增加。前者可能只是功能反应较差的结果。
To delineate the fidelity of the functional cortical organization in humans with amblyopia, we undertook an investigation into how spatial information is mapped across the visual cortex in amblyopic observers. We assessed whether the boundaries of the visual areas controlled by the amblyopic and fellow fixing eye are in the same position, the fidelity of the retinotopic map within different cortical areas and the average receptive field size in different visual areas. The functional organization of the visual cortex was reconstructed using a fMRI phase-encoded retinotopic mapping analysis. This method sequentially stimulates each point in the visual field along the axes of a polar-coordinate system, thereby reconstructing the representation of the visual field on the cortex. We found that the cortical areas were very similar in normals and amblyopes, with only small differences in boundary positions of different visual areas between fixing and fellow amblyopic eye activation. Within these corresponding visual areas, we did find anomalies in retinotopy in some but not all amblyopes that were not simply a consequence of the poorer functional responses and affected central and peripheral field regions. Only a small increase in the average (or collective) receptive field size was found for full-field representation in amblyopes and none at all for central field representation. The former may simply be a consequence of the poorer functional responses.