SEMANTIC FEATURE PROCESSING IN INDIVIDUALS WITH STROKE APHASIA

描述（由申请人提供）：单词检索困难是失语症患者中观察到的最常见症状，对个人日常生活中的沟通能力有着深远的影响。虽然人们早就认识到，充分处理的意义或“语义知识”是一个必要的先决条件，以准确的词检索，它仍然不清楚如何处理语义知识的不足影响失语症中观察到的词检索困难。长期目标是设计基于语义的失语症单词检索障碍的治疗方法，最大限度地利用语义信息的类型，以促进单词检索。这个项目的总体目标是确定失语症患者的语义特征知识、单词提取缺陷和病变位置之间的关系。中心假设是：（1）特定语义特征线索的处理不足将不同地影响其含义被加权以支持这些特征的概念的单词检索;以及（2）语义特征/概念处理不足与病变位置相关。该项目的基本原理是，理解语义知识和失语症的单词检索障碍之间的关系将提供基础，扩展到理论上的动机评估和治疗缺乏语义引导的词汇检索的临床研究。中心假设将通过追求以下两个具体目标进行测试：（1）确定语义特征线索和不同类型的对象概念的单词检索之间的关联，以及（2）确定语义特征/概念处理与失语症病变位置相关的程度。为了追求这些特定的目标，将使用神经心理学电池对失语症患者进行评估，该电池旨在提供相同活体和非活体物体内特征类型之间的直接比较。将收集失语症受试者的高分辨率MRI扫描，行为表现将与病变位置相关。一旦获得这些信息，就有可能区分表现模式，并辨别语义特征治疗的程度，以满足具有不同的单词检索障碍潜在机制的个体的需求。此外，识别语义特征和对象概念处理之间的相互作用将告知正在进行的理论辩论，是否损害不同类型的对象概念的处理是一个紧急的属性的功能处理缺陷，可以链接到病变位置。 公共卫生相关性：拟议的研究将有一个重要的积极影响，了解如何最好地设计理论动机的临床工具，以补救单词检索障碍的基础上，个人的能力，处理语义特征线索的知识。拟议的项目与公共卫生有关，因为要调查的机制将为评估和治疗单词检索障碍的发展提供信息，这些障碍可能会损害失语症患者日常生活中的沟通。

DESCRIPTION (provided by applicant): Word retrieval difficulty is the most common symptom observed in people with aphasia, having a profound impact on individuals' ability to communicate in daily life. While it has long been acknowledged that adequate processing of meaning or "semantic knowledge" is a necessary precursor to accurate word retrieval, it remains unclear how deficient processing of semantic knowledge influences word retrieval difficulties observed in aphasia. The long-term goal is to design semantically-based treatments for word retrieval impairment in aphasia that maximize the types of semantic information that are utilized to facilitate word retrieval. The overall objective of this project is to determine the relationships among semantic feature knowledge, word retrieval deficits, and lesion location in individuals with aphasia. The central hypothesis is that (1) deficient processing of specific semantic feature cues will differentially impact word retrieval for concepts whose meanings are weighted in favor of those features; and (2) deficient semantic feature/concept processing is associated with lesion location. The rationale for the proposed project is that understanding the relationship between semantic knowledge and word retrieval impairment in aphasia will provide the foundation upon which to expand clinical research into theoretically-motivated assessment and treatment of deficient semantically-guided lexical retrieval. The central hypothesis will be tested by pursuing the following two specific aims: (1) Determine the association between semantic feature cues and word retrieval for different types of object concepts, and (2) Determine the extent to which semantic feature/concept processing is associated with lesion location in aphasia. To pursue these specific aims, individuals with aphasia will be assessed using a neuropsychological battery designed to provide for direct comparison between feature types within the same living and nonliving objects. High resolution MRI scans will be collected for participants with aphasia and behavioral performance will be related to lesion location. Once this information has been obtained, it will be possible to differentiate patterns of performance and discern the extent to which semantic feature treatments may be tailored to meet the needs of individuals with differing underlying mechanisms of word retrieval impairment. Furthermore, identifying the interaction between semantic feature and object concept processing will inform ongoing theoretical debates regarding whether impairment to processing of different types of object concepts is an emergent property of feature-processing deficits that can be linked to lesion location. PUBLIC HEALTH RELEVANCE: The proposed research will have an important positive impact on understanding of how best to design theoretically-motivated clinical tools to remediate word retrieval impairment based on knowledge of individuals' ability to process semantic feature cues. The proposed project has relevance to public health because the mechanisms to be investigated will inform the development of assessments and treatments for word retrieval impairments that can compromise communication in the daily lives of individuals with aphasia.