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 这项建议的目的是调查词汇提取缺陷的个体的可变性的来源 左半球卒中引起的损害以及这些缺陷如何受到独特的影响取决于 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)损害的个体比较 配对的对照组。所有中风患者都在一定程度上观察到词汇提取障碍 失语症。词汇激活和选择是使我们能够在说话时提取单词的关键过程。词汇化 激活通过将激活从语义传播到词汇表示而发生，并在 语义相关的上下文。词汇选择是从激活的语义中选择目标词-- 相关的替代方案，在语义相关的上下文中可以减慢。词汇提取阶段可以是 根据语义语境的类型不同而受到不同的影响。与分类相关的单词(例如，狼和狗) 都与语义干扰联系在一起。然而，与主题相关的单词(例如，狗和皮带) 与促进联系在一起。失语症患者的词汇提取经常受损，但其驱动力 词汇提取缺陷的背后以及这些缺陷如何根据语义类型的不同而受到不同的影响 上下文没有被很好地理解。分离具有更大激活与选择缺陷的个体 来自有更多选择与激活缺陷的个人可能是一种更有信息量的方式 表征词汇提取缺陷，并可能有助于预测不同语义语境对更多 个性化的方式。在这里，我们提出激活缺陷，与词汇激活缺陷相对应， 与pLTC病变有关，因为pLTC中有病变的个体已被证明与 即使当呈现给他们一个选项时，也能识别正确的单词。相比之下，我们 提出选择缺陷，包括抑制共同激活的词汇项目的能力缺陷 选择与LPFC病变有关，因为LPFC已被提出在克服 语义干扰。目标1将词汇激活与选择提取缺陷的个体分开 通过使用允许这种分离的预先建立的行为范例。目标2将调查 PLTC和LPFC个体词汇提取子加工的分类和主题关系 通过使用电生理技术进行损伤。这项研究的结果将提供一个关键步骤 为了理解不同的词汇提取缺陷是如何与语义语境相互作用的，以及相关的 卒中失语的脑动力学研究，为临床今后的发展提供知识基础 词汇检索的评估工具。