Retinotopic organization in human visual cortex and the spatial precision of functional MRI
Retinotopic organization in human visual cortex and the spatial precision of functional MRI
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DOI：
10.1093/cercor/7.2.181
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发表时间：
1997-03-01
期刊：
影响因子：
3.7
通讯作者：
Wandell, BA
中科院分区：
文献类型：
--
作者：
Engel, SA;Glover, GH;Wandell, BA
描述了一种使用功能磁共振成像（fMRI）来测量人皮层内视网膜组织的方法。该方法基于视觉刺激，该刺激在视网膜组织的视觉区域内产生了神经活动的潮流。我们测量了视觉皮层中这种刺激引起的fMRI信号，并代表了扁平皮质片的图像的结果。我们使用该方法来定位视觉区域并评估fMRI的空间精度。具体而言，我们：（i）识别枕骨后叶中几个视网膜组织的视觉区域之间的边界； （ii）测量了面积V1内的皮质位置与视野偏心率有关的功能； （iii）在视觉皮层1.1 mm以内的局部活动； （iv）估计fMRI信号的空间分辨率，发现信号幅度在每9 mm的视觉皮层1周期时降至60％。该空间分辨率与线条相一致，该线路的全宽度为一半的最大宽度在3.5毫米的视觉皮层中扩散。
A method of using functional magnetic resonance imaging (fMRI) to measure retinotopic organization within human cortex is described. The method is based on a visual stimulus that creates a traveling wave of neural activity within retinotopically organized visual areas. We measured the fMRI signal caused by this stimulus in visual cortex and represented the results on images of the flattened cortical sheet. We used the method to locate visual areas and to evaluate the spatial precision of fMRI. Specifically, we: (i) identified the borders between several retinotopically organized visual areas in the posterior occipital lobe; (ii) measured the function relating cortical position to visual field eccentricity within area V1; (iii) localized activity to within 1.1 mm of visual cortex; and (iv) estimated the spatial resolution of the fMRI signal and found that signal amplitude falls to 60% at a spatial frequency of 1 cycle per 9 mm of visual cortex. This spatial resolution is consistent with a linespread whose full width at half maximum spreads across 3.5 mm of visual cortex.