Conscious visual abilities in a patient with early bilateral occipital damage
Conscious visual abilities in a patient with early bilateral occipital damage
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DOI：
10.1017/s0012162003001439
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发表时间：
2003-11-01
影响因子：
3.8
通讯作者：
Wong, PKH
中科院分区：
文献类型：
--
作者：
Giaschi, D;Jan, JE;Wong, PKH
一名 21 岁男性出生时枕叶因双侧梗塞而严重受损。解剖学和功能性 MRI 以及高分辨率脑电图证实了纹状皮层的缺失。他的皮质视觉障碍很严重，但他仍然保持着观察快速移动刺激的非凡能力。任何一只眼睛都可以引起水平视动眼球震颤。如果允许患者移动头部和眼睛，分辨率敏锐度接近正常。在超过 2 度/秒的速度下，可以完美准确地辨别随机点图案中的运动方向，并且患者报告说，他可以“看到”快速运动，但在慢速运动时看不到。这种有意识的运动残余视觉被称为 Riddoch 现象，但从未在纹状皮层完全缺失的情况下出现过这种现象。功能性神经影像学揭示了纹状外皮层运动反应区域之外的激活。这个案例展示了人类视觉系统的显着可塑性，可能对理解运动路径的功能组织具有影响。
A 21-year-old male presented with occipital lobes that were extensively damaged by bilateral infarcts present at birth. The absence of the striate cortex was confirmed with anatomic and functional MRI and high-resolution EEG. His cortical visual impairment was severe, but he retained a remarkable ability to see fast-moving stimuli. Horizontal optokinetic nystagmus could be elicited from either eye. Resolution acuity was close to normal providing the patient was allowed to move his head and eyes. The direction of motion in random-dot patterns could be discriminated with perfect accuracy at speeds above 2 deg/s, and the patient reported that he could 'see' the motion at fast but not at slow speeds. This conscious residual vision for, motion is known as Riddoch's phenomenon, but it has never been reported in the complete absence of the striate cortex. Functional neuroimaging revealed activation that was outside the motion-responsive regions of the extrastriate cortex. This case demonstrates remarkable plasticity in the human visual system and may have implications for understanding the functional organization of the motion pathways.