Longitudinal profiles of semantic impairment for living and nonliving concepts in dementia of Alzheimer's type
Longitudinal profiles of semantic impairment for living and nonliving concepts in dementia of Alzheimer's type
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DOI：
10.1162/089892901753165818
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发表时间：
2001-10-01
影响因子：
3.2
通讯作者：
Hodges, JR
中科院分区：
文献类型：
--
作者：
Garrard, P;Ralph, MAL;Hodges, JR
有两种理论解释了语义记忆测试中的类别特异性损伤现象：一种是强调不同的大脑皮层区域对生命和非生命类别表征的重要性，另一种是强调属于这两个广义语义域的概念特征之间的统计关系的重要性。后一种理论预测，领域优势的方向在很大程度上将由语义系统的整体损害决定，而语义记忆进行性损害患者的概况可能包括一个领域的优势转变为另一个领域的优势的点。本系列的三项研究使用了来自两个不同的阿尔茨海默氏型痴呆(DAT)患者的语义测试数据，以寻找这种交叉的证据。在第一项研究中，对58名患者的纵向测试分数进行了检查，以确认这一组患者存在进行性语义恶化。在第二项研究中，基于连续命名反应的Kaplan-Meier生存曲线分别绘制了属于生命领域和非生命领域的条目，表明生命概念的表征(通过命名衡量)的退化速度一致且显著快于非生命概念。第三项研究是为了详细观察受轻微影响的患者的表现，使用了另外20名患有轻度DAT的患者的横断面队列，并使用了分级命名评估。这项研究也没有证据表明，作为疾病严重程度的函数，一个领域相对于另一个领域的优势存在交叉。结合Braak和Braak(1991)在DAT中的解剖进展模型，这些发现被解释为局部大脑解剖对DAT中语义域效应产生的重要性的证据。
Two types of theoretical account have been proposed to explain the phenomenon of category-specific impairment in tests of semantic memory: One stresses the importance of different cortical regions to the representation of living and nonliving categories, while the other emphasize the importance of statistical relationships among features of concepts belonging to these two broad semantic domains. Theories of the latter kind predict that the direction of a domain advantage will be determined in large part by the overall damage to the semantic system, and that the profiles of patients with progressive impairments of semantic memory are likely to include a point at which an advantage for one domain changes to an advantage for the other. The present series of three studies employed semantic test data from two separate cohorts of patients with probable dementia of Alzheimer's type (DAT) to look for evidence of such a crossover. In the first study, longitudinal test scores from a cohort of 58 patients were examined to confirm the presence of progressive semantic deterioration in this group. In the second study, Kaplan-Meier survival curves based on serial naming responses and plotted separately for items belonging to living and nonliving domains indicated that the representations of living concepts (as measured by naming) deteriorated at a consistently and significantly faster rate than those of nonliving concepts. A third study, carried out to look in detail at the performance of mildly affected patients, employed an additional cross-sectional cohort of 20 patients with mild DAT and utilized a graded naming assessment. This study also revealed no evidence for a crossover in the advantage of one domain over the other as a function of disease severity. Taken together with the model of anatomical progression in DAT based on the work of Braak and Braak (1991), these findings are interpreted as evidence for the importance of regional cerebral anatomy to the genesis of semantic domain effects in DAT.