Biases in attentional orientation and magnitude estimation explain crossover: neglect is a disorder of both.
Biases in attentional orientation and magnitude estimation explain crossover: neglect is a disorder of both.
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注意方向和强度估计的偏差解释了交叉：忽视是两者的障碍。
DOI：
10.1162/0898929055002454
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Mark,VictorW
中科院分区：
文献类型：
--
作者：
Mennemeier,Mark;Pierce,ChristopherA;Chatterjee,Anjan;Anderson,Britt;Jewell,George;Dowler,Rachael;Woods,AdamJ;Glenn,Tannahill;Mark,VictorW
交叉是指在直线平分测试中的一种表现模式，其中短线在与长线真正中心相对的一侧被平分。虽然大多数空间忽视患者表现出交叉，当代的忽视理论不能解释it. In相比之下，我们表明，混合的心理物理结构的大小估计与忽视理论不仅解释交叉，而且还解决了忽视的定量特征，是独立的空间赤字。我们报告了交叉的方向/估计假设的前瞻性验证研究。40例受试者（17例单侧脑损伤和23例正常对照）完成了四个实验，检查交叉使用线平分，线平分提示，并从记忆和标准再现线长度。复制早期的研究结果，除了一个主题组表现出交叉的标准线平分测试，所有组都表现出自发的偏好，以定向注意线的一端，所有组高估了短线的长度和低估了长线。忽视患者的注意力方向和大小估计偏差被夸大。这项研究的真正新颖的发现发生在，从平分任务中删除线后，交叉的方向在所有受试者组中完全逆转，这取决于注意力的方向。这些发现与我们的交叉假设相一致：（1）交叉是直线平分操作的正态成分，（2）交叉是注意方向偏差和量估计偏差相互作用的结果;（3）注意力定向预测交叉方向，而先前在忽视中没有强调的幅度估计障碍，解释了长度估计的数量变化，使交叉在忽视被试中更加明显。奇怪的是，我们观察到传统的线平分测试是次优探索交叉，因为线引起自发的方向反应，混淆实验操作的注意。我们的结论是，注意力方向和幅度估计是必要的，足以解释交叉和幅度估计的偏差是忽视的核心组成部分。
Crossover refers to a pattern of performance on the line bisection test in which short lines are bisected on the side opposite the true center of long lines. Although most patients with spatial neglect demonstrate crossover, contemporary theories of neglect cannot explain it. In contrast, we show that blending the psychophysical construct of magnitude estimation with neglect theory not only explains crossover, but also addresses a quantitative feature of neglect that is independent of spatial deficits. We report a prospective validation study of the orientation/estimation hypothesis of crossover. Forty subjects (17 patients with and without neglect following unilateral brain injury and 23 normal controls) completed four experiments that examined crossover using line bisection, line bisection with cueing, and reproducing line lengths from both memory and a standard. Replicating earlier findings, all except one subject group exhibited crossover on the standard line bisection test, all groups showed a spontaneous preference to orient attention to one end of the lines, and all groups overestimated the length of short lines and underestimated long lines. Biases in attentional orientation and magnitude estimation are exaggerated in patients with neglect. The truly novel finding of this study occurred when, after removing the line from the bisection task, the direction of crossover was completely reversed in all subject groups depending on where attention was oriented. These findings are consistent with our hypothesis of crossover: (1) crossover is a normal component of performance on line bisection; (2) crossover results from the interplay of biases in attentional orientation and magnitude estimation; and (3) attentional orientation predicts the direction of crossover, whereas a disorder of magnitude estimation, not previously emphasized in neglect, accounts for the quantitative changes in length estimation that make crossover more obvious in neglect subjects. Paradoxically, we observed that the traditional line bisection test is suboptimal for exploring crossover because lines elicit spontaneous orientation responses from subjects that confound experimental manipulations of attention. We conclude that attentional orientation and magnitude estimation are necessary and sufficient to explain crossover and that bias in magnitude estimation is a core component of neglect.