Optic ataxia is not only 'optic': Impaired spatial integration of proprioceptive information
Optic ataxia is not only 'optic': Impaired spatial integration of proprioceptive information
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DOI：
10.1016/j.neuroimage.2007.03.039
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发表时间：
2007-01-01
期刊：
影响因子：
5.7
通讯作者：
Pisella, L.
中科院分区：
文献类型：
--
作者：
Blangero, A.;Ota, H.;Pisella, L.
视性共济失调被认为是一种特定的视觉-手动引导缺陷，其结合了由于使用对侧病灶手（“手效应”）和在对侧病灶场中呈现视觉目标（“场效应”）而导致的指向错误。手效应的性质尚未确定。场效应被认为是视觉目标定位的空间整合受损。然而，从手臂的本体感受信息的空间整合从未在这些患者中进行过实验测试。在这里，我们专门调查了两名单侧视神经共济失调患者在任务中的能力，这些任务需要不同水平的本体感受整合，从初级信息处理到本体感受运动整合。在第一个实验中-本体感觉指向同侧病变的手对侧病变的手的食指-揭示了一个大的错位的共济失调的手占手的效果。在第二个实验中-本体感觉指向与共济失调的手臂对手指的同病手-发现达到错误的非视觉目标，即视性共济失调是不具体的“光学”的目标。总之，目前的结果要求重新定义顶叶功能的框架内，这种神经系统的条件。(C)2007年爱思唯尔公司All rights reserved.
Optic ataxia is considered to be a specific visuo-manual guidance deficit, which combines pointing errors due to the use of the contralesional hand ("hand effect") and to the presentation of the visual target in the contralesional field ("field effect"). The nature of the hand effect has not been identified. The field effect is acknowledged as an impaired spatial integration of visual target location. However, spatial integration of proprioceptive information from the arm has never been experimentally tested in these patients. Here, we specifically investigated the capacity of two patients with unilateral optic ataxia in tasks requiring different levels of proprioceptive integration from primary information processing to proprioceptivo-motor integration. In a first experiment -proprioceptive pointing with the ipsilesional hand toward the index finger of the contralesional hand- revealed a large mislocalisation of the ataxic hand accounting for the hand effect. In a second experiment -proprioceptive pointing with the ataxic arm toward the finger of the ipsilesional hand- revealed reaching errors for non-visual targets, i.e. optic ataxia is not specific to 'optic' targets. Altogether, the present results call for a redefinition of this neurological condition in the framework of parietal functions. (C) 2007 Elsevier Inc. All rights reserved.