Lexical retrieval, verbal short-term memory and learning

我们将探讨文字处理的认知组织，言语短时记忆（STM）和单词 学习这三种能力是学习的基础，它们的完整性对 神经学语言缺陷的康复。我们建议继续研究 失语症患者语言、短时记忆和学习能力的语义和语音障碍 并将这些分析扩展到语义痴呆症患者。我们的重点将放在 语义障碍对这些人群的学习和治疗反应的影响。语义 语义性痴呆和失语症都存在损害，但两者表现不同。 人口。这些差异尚未完全理解，但被广泛地表征为语义差异。 访问与语义知识损伤。我们的目标是阐明行为和神经解剖学 语义通达和知识障碍的特征以及各自对文字处理、STM和 学习我们将获得以下四组的行为和神经影像学数据（结构MRI扫描）： 他们的损害（失语症，语义性痴呆）和破坏的一个内的位点的病因， 文字处理的心理语言学模型。此外，我们将确定强调语义短的因素- 长期工作记忆测试的假设，这一因素是在语义访问赤字的根源， 语义短时记忆缺陷与执行功能受损有关。在第二个项目中，我们将 失语症患者语义和语音障碍对学习识别和产生影响研究 新的单词，以确定这些障碍如何影响这一过程。这个项目与第三个 正在进行的项目，调查启动治疗失语症的单词检索障碍。我们的目标是 测试我们的一个新版本的上下文启动治疗的有效性，目标是命名的输出通路 直接.在这三个项目中收集到的认知数据将被用来影响Ongioing 发展一个言语短时记忆、文字处理和学习的计算模型。

We will investigate the cognitive organization of word processing, verbal short-term memory (STM) and word learning. These three capacities are fundamental to learning, and their integrity has implications for rehabilitation of neurologically-based language deficits. We propose to continue our studies of the effects of semantic and phonological impairment on language, STM and learning abilities of individuals with aphasia and will extend these analyses to individuals with semantic dementia. Our focus will be on the detrimental effects of semantic impairments on learning and response to treatment in these populations. Semantic impairments are present in both semantic dementia and aphasia but are manifested differently in the two populations. These differences are as yet not fully understood but are broadly characterized as semantic access vs. semantic knowledge impairments. Our goal is to elucidate the behavioral and neuroanatomical features of semantic access and knowledge disorders and the effects of each on word processing, STM and learning. We will obtain behavioral and neuroimaging data (structural MRI scans) on four groups defined by the etiology of their impairment (aphasia, semantic dementia) and locus of disruption within a psycholinguistic model of word processing. Additionally, we will identify factors that stress semantic short- term working memory to test the hypothesis that this factor is at the root of semantic access deficits and that semantic STM deficits are associated with impaired executive functions. In a second project, we will investigate effects of semantic and phonological impairment in aphasia on learning to recognize and produce new words in order to determine how these impairments affect this process. This project is linked to a third ongoing project that investigates priming treatments for word retrieval disorders in aphasia. Here we aim to test the efficacy of a new version of our contextual priming treatment that targets output pathways of naming directly. The cognitive data gathered in these three projects will be brought to bear on the ongioing development of a computational model of verbal STM, word processing and learning.