No right to speak? The relationship between object naming and semantic impairment: Neuropsychological abstract evidence and a computational model
No right to speak? The relationship between object naming and semantic impairment: Neuropsychological abstract evidence and a computational model
复制标题
DOI：
10.1162/08989290151137395
复制
发表时间：
2001-04-01
影响因子：
3.2
通讯作者：
Hodges, JR
中科院分区：
文献类型：
--
作者：
Ralph, MAL;McClelland, JL;Hodges, JR
在一项对语义性痴呆患者的研究(进行性颞叶萎缩导致的语义记忆选择性下降)和一个单字产生的计算模型中，对物体命名所需的过程进行了研究。尽管所有的语义性痴呆患者在单字产生和理解方面都有损害，但以往的报道指出了两种不同的模式：(A)命名和理解的准确性平行下降，并经常出现语义命名错误，这表明贫血是纯粹的语义基础；(B)严重的进行性贫血，但没有相应的理解下降，这可能表明主要是语义后来源的异常。16名语义性痴呆患者的纵向数据反映了这两种特征，但还有以下其他重要指标：(1)尽管有几个相对极端的版本，但对于给定程度的理解退化，完整的病例在异常程度上形成了一个连续体；(2)这两种能力之间的差异程度与萎缩侧向的相对不对称性有关：两种测量方法平行下降，表现为患者右侧比左侧-颞叶萎缩更大，而不成比例的贫血发生，以左侧颞叶萎缩为主。在一个实现的命名计算模型中，语义表征分布在模拟的左和右时间区域，但左边的语义单位与左侧化的音位表征联系更紧密。对语义单位的非对称性损伤再现了命名相对于理解的纵向患者轮廓。再加上CHE患者命名表现的其他特点。在神经心理学和计算证据的基础上，我们提出，仅语义障碍就可以解释本文所述的所有词汇产生缺陷。
The processes required for object naming were addressed in a study of patients with semantic dementia (a selective decline of semantic memory resulting from progressive temporal lobe atrophy) and in a computational model of single-word production. Although all patients with semantic dementia are impaired in both single-word production and comprehension, previous reports had indicated two different patterns: (a) a parallel decline in accuracy of naming and comprehension with frequent semantic naming errors, suggesting a purely semantic basis for the anemia and (b) a dramatic progressive anemia without commensurate decline in comprehension, which might suggest a mainly postsemantic source of the anomia. Longitudinal data for 16 patients with semantic dementia reflected these two profiles, but with the following additional important specifications: (1) despite a few relatively extreme versions of one or other profile, the full set of cases formed a continuum in the extent of anomia for a given degree of degraded comprehension; (2) the degree of disparity between these two abilities was associated with relative asymmetry in laterality of atrophy: a parallel decline in the two measures characterized patients with greater right than left-temporal atrophy, while disproportionate anemia occurred with a predominance of atrophy in the left-temporal lobe. In an implemented computational model of naming, semantic representations were distributed across simulated left- and right-temporal regions, but the semantic units on the left were more strongly connected to left-lateralized phonological representations. Asymmetric damage to semantic units reproduced the longitudinal patient profiles of naming relative to comprehension. plus additional characteristics of che patients' naming performance. On the basis of both the neuropsychological and computational evidence, we propose that semantic impairment alone can account for the full range of word production deficits described here.