Absence of visual feedback abolishes expression of hemispatial neglect in self-guided spatial completion
Absence of visual feedback abolishes expression of hemispatial neglect in self-guided spatial completion
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缺乏视觉反馈消除了自我引导空间完成中半侧空间忽视的表达
DOI：
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发表时间：
2011
影响因子：
11
通讯作者：
R. Ptak
中科院分区：
文献类型：
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作者：
A. Schnider;Vanessa Blanche Durbec;R. Ptak
背景 左侧忽视的患者将注意力过分集中到右侧。假设认为，这是由于未能将注意力从右侧刺激中分离出来，或者注意力偏向于右侧空间。目的 测试患者自己放置在屏幕上的视觉干扰物的持续与不存在如何影响忽视的表达。方法 要求 13 名左侧忽视患者和 6 名右侧半球受损的非忽视患者通过点击电脑鼠标在屏幕上均匀分布 120 个点。在反馈条件下，点仍然可见；在无反馈条件下，屏幕在整个任务过程中保持空白。结果在被忽视的患者中，这两种情况明显相互分离，但在对照组中则不然。在反馈条件下，忽视患者将初始点向右移动，然后保持这种空间偏差直到任务结束。相比之下，在无反馈条件下，他们在整个屏幕上放置的点更加均匀；事实上，当没有关于点位置的视觉反馈时，典型的半侧空间忽视的正确空间偏差实际上消失了。结论 缺乏关于自我放置刺激位置的视觉反馈显着减弱了半侧空间忽视。这一发现与脱离障碍作为视觉忽视的主要因素相一致，并可能产生治疗效果。
Background Patients with left neglect direct their attention too strongly to the right. Hypotheses hold that this is due to a failure to disengage attention from right-sided stimuli or to a directional bias of attention into right space. Objective To test how persistence versus absence of visual distracters, which the patients themselves placed on a screen, influenced the expression of neglect. Methods 13 patients with left neglect and six right-hemisphere-damaged control patients without neglect were asked to evenly distribute 120 dots on a screen by clicking the computer mouse. In the Feedback condition, dots remained visible; in the No-feedback condition, the screen remained blank throughout the task. Results The two conditions strikingly dissociated from each other in neglect patients but not in controls. In the Feedback condition, neglect patients placed initial dots with a rightward shift and then maintained this spatial bias till the end of the task. In the No-feedback condition, by contrast, they placed dots much more evenly over the whole screen; indeed, the right spatial bias typical of hemispatial neglect virtually disappeared when there was no visual feedback about the dot placements. Conclusion Absence of visual feedback about the location of self-placed stimuli markedly attenuated hemispatial neglect. The finding is compatible with impaired disengagement as the prevailing factor of visual neglect and may have therapeutic consequences.