Intact hemisphere and corpus callosum compensate for visuomotor functions after early visual cortex damage
Intact hemisphere and corpus callosum compensate for visuomotor functions after early visual cortex damage
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DOI：
10.1073/pnas.1714801114
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发表时间：
2017-11-28
影响因子：
11.1
通讯作者：
Tamietto, Marco
中科院分区：
文献类型：
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作者：
Celeghin, Alessia;Diano, Matteo;Tamietto, Marco
初级视皮层（V1）的单侧损伤导致对侧视觉半野的临床失明，但将看不见的视觉输入转化为运动输出的无意识能力可以保留，这种情况称为“盲视”。“在这里，我们结合了心理物理学，功能性磁共振成像和纤维束成像来研究功能和结构特性，这些特性使发育中的大脑能够部分克服一名失明患者早期V1病变的影响。视觉刺激出现在完整的或盲目的半野和简单的反应，无论是左手或右手，从而创造条件，视觉输入和运动输出涉及相同或相反的半球。当V1受损半球受到外来视觉刺激或对这些看不见的刺激的受控手动反应的挑战时，胼胝体（CC）动态地招募完整半球的视觉背流和前运动皮层中的区域以补偿改变的视觉功能。这些功能性脑活动的代偿性变化被CC后部区域的连接增加所掩盖，CC后部区域是连接顶叶皮质同源区域的纤维路线。
Unilateral damage to the primary visual cortex (V1) leads to clinical blindness in the opposite visual hemifield, yet nonconscious ability to transform unseen visual input into motor output can be retained, a condition known as "blindsight." Here we combined psychophysics, functional magnetic resonance imaging, and tractography to investigate the functional and structural properties that enable the developing brain to partly overcome the effects of early V1 lesion in one blindsight patient. Visual stimuli appeared in either the intact or blind hemifield and simple responses were given with either the left or right hand, thereby creating conditions where visual input and motor output involve the same or opposite hemisphere. When the V1-damaged hemisphere was challenged by incoming visual stimuli, or controlled manual responses to these unseen stimuli, the corpus callosum (CC) dynamically recruited areas in the visual dorsal stream and premotor cortex of the intact hemisphere to compensate for altered visuomotor functions. These compensatory changes in functional brain activity were paralleled by increased connections in posterior regions of the CC, where fibers connecting homologous areas of the parietal cortex course.