"Pre-semantic" cognition revisited: Critical differences between semantic aphasia and semantic dementia
"Pre-semantic" cognition revisited: Critical differences between semantic aphasia and semantic dementia
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DOI：
10.1016/j.neuropsychologia.2009.09.011
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发表时间：
2010-01-01
期刊：
影响因子：
2.6
通讯作者：
Ralph, Matthew A. Lambon
中科院分区：
文献类型：
--
作者：
Jefferies, Elizabeth;Rogers, Timothy T.;Ralph, Matthew A. Lambon
语义性痴呆患者在语言和非语言的“前语义”任务上表现出特定的损伤模式，例如，阅读出声、过去时态生成、听写拼写、词汇判断、物体判断、颜色判断和延迟图片复制。所有七项任务的特点是表现较差的项目是非典型的领域和“正规化错误”（不规则/非典型项目的生产，如果他们是典型的领域）。这种模式在同一患者的不同任务中的出现表明，语义记忆在所有这些类型的“前语义”处理中起着关键作用。然而，这种说法仍然存在争议，因为语义受损的患者有时未能表现出规律性的影响。这项研究表明，（a）脑损伤的位置和（B）语义缺陷的潜在性质影响观察到预期的理解力差和规律性效应之间的关系的可能性。我们比较了语义性痴呆和卒中性失语背景下多模态语义障碍对上述七项“前语义”任务的影响。在所有这些任务中，语义性失语症患者对典型性的敏感性低于语义性痴呆患者，尽管两组在语义测试中获得了相当的分数。语义失语症组也较少规则化错误和更多无关和持续的反应。我们建议，这些组的差异反映了不同的位点的语义障碍在两种情况下：语义性痴呆患者的语义表征退化，而语义性失语症患者表现出失调的语义认知伴随执行缺陷。这些研究结果表明，理解受损的失语症患者谁没有表现出预期的效果规律性的“前语义”任务的单例研究的重新解释。因此，这些案例并不能证明这些任务独立于语义记忆。(C)2009爱思唯尔有限公司版权所有。
Patients with semantic dementia show a specific pattern of impairment on both verbal and non-verbal, "pre-semantic" tasks, e.g., reading aloud, past tense generation, spelling to dictation, lexical decision, object decision, colour decision and delayed picture copying. All seven tasks are characterised by poorer performance for items that are atypical of the domain and "regularisation errors" (irregular/atypical items are produced as if they were domain-typical). The emergence of this pattern across diverse tasks in the same patients indicates that semantic memory plays a key role in all of these types of "pre-semantic" processing. However, this claim remains controversial because semantically impaired patients sometimes fail to show an influence of regularity. This study demonstrates that (a) the location of brain damage and (b) the underlying nature of the semantic deficit affect the likelihood of observing the expected relationship between poor comprehension and regularity effects. We compared the effect of multimodal semantic impairment in the context of semantic dementia and stroke aphasia on the seven "pre-semantic" tasks listed above. In all of these tasks, the semantic aphasia patients were less sensitive to typicality than the semantic dementia patients, even though the two groups obtained comparable scores on semantic tests. The semantic aphasia group also made fewer regularisation errors and many more unrelated and perseverative responses. We propose that these group differences reflect the different locus for the semantic impairment in the two conditions: patients with semantic dementia have degraded semantic representations, whereas semantic aphasia patients show deregulated semantic cognition with concomitant executive deficits. These findings suggest a reinterpretation of single-case studies of comprehension-impaired aphasic patients who fail to show the expected effect of regularity on "pre-semantic" tasks. Consequently, such cases do not demonstrate the independence of these tasks from semantic memory. (C) 2009 Elsevier Ltd. All rights reserved.