Lexical retrieval deficits across semantic contexts in stroke-induced aphasia

中风引起的失语症跨语义上下文的词汇检索缺陷

• 批准号: 10537244
• 负责人: Elizabeth Jane Anderson
• 金额: $ 3.65万
• 依托单位: SAN DIEGO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10537244
• 关键词: Affect; Aphasia; Behavior; Behavioral; Behavioral Paradigm; Brain; Brain region; Canis familiaris; Categories; Clinical Assessment Tool; Communication; Dissociation; Electrophysiology (science); Frequencies; Future; Goals; Image; Impairment; Individual; Intervention; Knowledge; Language; Lead; Left; Lesion; Link; Location; Measures; Modeling; Names; Nature; Outcome; Patients; Performance; Play; Prefrontal Cortex; Process; Production; Research; Research Project Grants; Resolution; Retrieval; Role; Semantics; Source; Specificity; Speech; Stroke; Taxonomy; Techniques; Temporal Lobe; Testing; Wolves; clinical development; design; driving force; individualized medicine; innovation; lexical; lexical retrieval; personalized medicine; stroke-induced aphasia; treatment choice; treatment planning

Project Summary The goal of this proposal is to investigate the sources of variability in lexical retrieval deficits in individuals with left hemisphere stroke-induced lesions and how these deficits may be uniquely impacted depending on semantic context. We will achieve this by examining the brain dynamics of lexical retrieval and behavior in individuals with left prefrontal cortex (LPFC) versus left posterior temporal cortex (pLTC) lesions compared to matched controls. Lexical retrieval deficits are observed to some extent in all individuals with stroke-induced aphasia. Lexical activation and selection are key processes enabling us to retrieve words as we speak. Lexical activation occurs through spreading activation from semantic to lexical representations and is facilitated in semantically-related contexts. Lexical selection is the selection of the target word from activated semantically- related alternatives and can be slowed in semantically-related contexts. Lexical retrieval stages can be differently affected depending on the type of semantic context. Taxonomically-related words (e.g., wolf and dog) have been linked with semantic interference. However, thematically-related words (e.g., dog and leash) have been linked with facilitation. Lexical retrieval is often impaired in individuals with aphasia, but the driving forces behind lexical retrieval deficits and how these may be differentially impacted depending on the type of semantic context are not well understood. Separating individuals who have a greater activation versus selection deficit from individuals who have a greater selection versus activation deficit may be a more informative way to characterize lexical retrieval deficits and may help predict the impact of different semantic contexts in a more individualized manner. Here, we propose that activation deficits, corresponding to a deficit in lexical activation, are associated with pLTC lesions as individuals with lesions in the pLTC have been shown to struggle with recognizing the correct word even when presented to them as an option to choose from. Contrastively, we propose that selection deficits, involving a deficit in the ability to suppress co-activated lexical items during selection, are associated with LPFC lesions as the LPFC has been proposed to play a role in overcoming semantic interference. Aim 1 will dissociate individuals with lexical activation versus selection retrieval deficits by using pre-established behavioral paradigms allowing this dissociation. Aim 2 will investigate the impact of taxonomic and thematic relationships on lexical retrieval subprocesses in individuals with pLTC and LPFC lesions through the use of electrophysiological techniques. The results of this study will provide a key step towards understanding how different lexical retrieval deficits interact with semantic contexts, and the associated brain dynamics in stroke-induced aphasia, providing a knowledge basis for the future development of clinical assessment tools for lexical retrieval.

项目摘要 本研究的目的是探讨在个体的词汇提取缺陷的变异性的来源， 左半球卒中引起的病变以及这些缺陷如何受到独特的影响， 语义语境我们将通过研究词汇提取和行为的大脑动力学来实现这一点， 左前额叶皮质（LPFC）与左后颞叶皮质（pLTC）病变的个体相比， 匹配的控制。在所有脑卒中患者中均观察到一定程度的词汇提取缺陷。 失语症词汇激活和选择是我们说话时提取词汇的关键过程。词汇 激活通过从语义到词汇表征的激活扩散发生， 语义相关的上下文。词汇选择是从语义激活中选择目标词- 在语义相关的上下文中可以放慢速度。词汇检索阶段可以是 不同的影响取决于语义上下文的类型。分类学相关的词（例如，狼与狗（Wolf and Dog） 与语义干扰有关。然而，主题相关的词（例如，狗和皮带）有 与便利化有关。失语症患者的词汇提取能力通常会受损，但其驱动力 词汇检索缺陷背后，以及这些可能会受到不同的影响，取决于语义的类型 上下文没有很好地理解。分离出那些具有更大激活与选择缺陷的个体 从那些有更大的选择与激活缺陷的人身上获得的信息可能是一种更有信息性的方式， 描述词汇提取缺陷，并可能有助于预测不同语义背景的影响， 个性化的方式。在这里，我们提出激活缺陷，对应于词汇激活缺陷， 与pLTC病变相关，因为pLTC病变的个体已被证明与 识别正确的单词，即使是作为一个选项提供给他们选择。相反，我们 提出，选择缺陷，包括在抑制共同激活的词汇项目的能力缺陷， 选择，与LPFC病变相关，因为LPFC已被提出在克服 语义干扰目标1将区分词汇激活与选择提取缺陷的个体 通过使用预先建立的行为模式来允许这种分离。目标2将调查 pLTC和LPFC患者词汇提取子过程的分类和主题关系 通过使用电生理学技术治疗病变。这项研究的结果将提供一个关键步骤， 理解不同的词汇提取缺陷如何与语义上下文相互作用，以及相关的 脑卒中失语症的脑动力学研究，为今后临床的发展提供知识基础 词汇检索的评估工具。