a Department of Neurology , Johns Hopkins University , Baltimore , MD, USA.
b Department of Cognitive Science , Johns Hopkins University , Baltimore , MD, USA.
Cogn Neuropsychol. 2019 Feb-Mar;36(1-2):31-53. doi: 10.1080/02643294.2019.1587397. Epub 2019 Mar 8.
According to most models of language production, to name a picture one must first map semantic features onto lexical items. Even if both sets of representations are intact, problems in mapping semantic to lexical representations can impair production. Individuals with this problem, sometimes referred to as "access deficit", often demonstrate evidence of preserved semantic knowledge (e.g., good comprehension), increased rate of lexical (usually semantic) errors in production, and inconsistent accuracy on naming the same picture on different occasions. In this paper, I argue that access deficit can have two distinct etiologies. I will present a case of double dissociation between two individuals with chronic post-stroke aphasia, one of whom shows a profile compatible with impaired activation of the target lexical item from semantic features (), while the other shows a profile compatible with impaired inhibition of competing lexical items (). These results have three key implications: (a) they provide support for the theoretical separation between activation and selection processes in computational models of word production, (b) they point to the critical role of inhibitory control in lexical selection, and (c) they invite a closer inspection of the origin of semantic errors in individuals with access deficit in order to choose the best treatment option.
根据大多数语言产生模型，命名图片必须首先将语义特征映射到词汇项目上。即使这两套表示都完整无缺，语义到词汇表示的映射问题也会损害产生。有这个问题的人，有时被称为“访问缺陷”，通常表现出保留语义知识的证据（例如，良好的理解），在产生词汇（通常是语义）错误的速度增加，以及在不同场合对同一图片的命名准确性不一致。在本文中，我认为访问缺陷可能有两种不同的病因。我将介绍一个患有慢性中风失语症的两个人的双重分离案例，其中一个人的情况与目标词汇项目从语义特征的激活受损（）兼容，而另一个人的情况与竞争词汇项目的抑制受损（）兼容。这些结果有三个关键含义：（a）它们为词汇产生的计算模型中的激活和选择过程的理论分离提供了支持，（b）它们指出了抑制控制在词汇选择中的关键作用，（c）它们邀请更仔细地检查有访问缺陷的个体的语义错误的起源，以便选择最佳的治疗方案。
