Simultanagnosia: Effects of semantic category and repetition blindness
Simultanagnosia: Effects of semantic category and repetition blindness
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DOI：
10.1016/j.neuropsychologia.2007.08.024
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发表时间：
2008-01-01
期刊：
影响因子：
2.6
通讯作者：
Lie, Eunhui
中科院分区：
文献类型：
--
作者：
Coslett, H. Branch;Lie, Eunhui
当在很短的时间内面对两个相同的刺激时，受试者常常无法报告第二个刺激，这种现象被称为“重复失明”。 “类型标记”的解释将这种现象归因于未能对样本进行个体化。我们报告了一名受试者 KE，由于双侧顶叶梗塞，他出现了同时失认症（无法看到阵列中的多个项目）。通过无限时间地呈现两个单词、图片或字母，KE 通常在不到一半的试验中报告这两种刺激。数组中项目之间的语义关系对性能有显着影响。如果这两个项目在语义上相关，他报告的频率就会显着提高。相比之下，当对同一项目进行相同或视觉上不同的描述时，他仅在 2-4% 的试验中报告了这两个项目。表现不受刺激之间视觉相似性的影响；他报告视觉上不同的物体的频率低于视觉上相似但不同的物体。我们认为 KE 的双侧顶叶损伤阻止了保留的物体表征与背侧视觉系统计算的表征的结合。更一般地说，这些数据与后顶叶皮层通过计算其独特的时空特征来个体化刺激至关重要的说法是一致的。 (c) 2007 Elsevier Ltd. 保留所有权利。
When confronted with two identical stimuli in a very brief period of time subjects often fail to report the second stimulus, a phenomenon termed "repetition blindness". The "type-token" account attributes the phenomenon to a failure to individuate the exemplars. We report a subject, KE, who developed simultanagnosia (the inability to see more than one item in an array) as a consequence of bilateral parietal lobe infarctions. With presentation of two words, pictures or letters for an unlimited time, KE typically reported both stimuli on less than half of trials. Performance was significantly influenced by the semantic relationship between items in the array. He reported both items significantly more frequently if they were semantically related; in contrast, when presented either identical or visually different depictions of the same item, he reported both items on only 2-4% of trials. Performance was not influenced by the visual similarity between the stimuli; he reported visually dissimilar objects less frequently than visually similar but different objects. We suggest that KE's bilateral parietal lesions prevent the binding of preserved object representations to a representation computed by the dorsal visual system. More generally, these data are consistent with the claim that the posterior parietal cortex is crucial for individuating a stimulus by computing its unique spatio-temporal characteristics. (c) 2007 Elsevier Ltd. All rights reserved.