Indices of Lexical Access During Idiom Comprehension

描述（由申请人提供）：本项目研究失语症患者的口语理解能力，失语症是中风后获得的一种语言障碍。失语症有几种亚型，每一种都有特有的语言障碍；这个项目专门研究了布洛卡失语症的听觉句子理解。该领域的先前研究使用了在线方法和离线方法，前者具有时间敏感性，检查理解的每时每一刻的认知过程，后者具有时间敏感性，检查理解的结果。从先前的工作中，提出了一个假设，即布罗卡失语症患者的在线词汇（单词水平）处理缺陷是该人群离线理解障碍的基础。特别是，目前的建议调查了一个理论断言，即与健康听者的词汇加工相比，布洛卡失语症的词汇加工延迟。本研究利用惯用语（IPs）来研究布洛卡失语症词汇加工的时间过程。惯用语被认为是具有多重意义（字面和比喻）的长词汇项目。例如，IP ‘hit the sack’与一个比喻意义(例如：’to go sleep’)，但是这个短语中的每个单词都有独立的字面意思(例如：睡觉。‘strike’和‘bag’)。在当前的研究中使用了IP，因为先前对未受损听众的研究表明，这些健康个体在词汇上处理IP的字面和比喻意义，但时间尺度略有偏移。也就是说，典型的听者在对IP的字面意义进行词汇处理之前，先开始对IP的比喻意义进行词汇处理。这种时间上的差异激发了当前的建议，并将允许对布洛卡失语症中词汇获取的时间进程进行仔细研究。本项目将IP嵌入到听觉句子语境中，并使用在线方法，研究Broca失语症中每时每刻的词汇处理过程中IP在听觉理解中的意义。本研究的目的是：1)确定Broca失语症患者在听觉句子理解过程中，对IP的一个或两个含义的词汇加工是否延迟；2)质疑具有多重含义的词汇项目（即ip）是否会引发延迟词汇加工，还是词汇加工本身就存在延迟；3)探讨Broca失语症中ip的离线理解。当前项目的结果将通过深入了解这些障碍背后的处理机制，为布洛卡失语症的语言理解缺陷提供理论模型。该项目还可以通过强调语言的特定元素（即词汇处理速度）来指导布洛卡失语症的治疗。

DESCRIPTION (provided by applicant): This project examines spoken language comprehension in individuals with aphasia, a language disorder acquired subsequent to stroke. There are several sub-types of aphasia, each with characteristic language impairments; this project specifically examines auditory sentence comprehension in Broca's aphasia. Prior research in the field has utilized both on-line methods, which are temporally-sensitive and examine the moment-by-moment cognitive processes of comprehension, as well as off-line methods, which are temporally- insensitive and examine the outcome of comprehension. From this prior work, a hypothesis has been put forward that an on-line lexical (word-level) processing deficit in Broca's aphasia underlies off-line comprehension impairments in this population. In particular, the current proposal investigates a theoretical assertion that lexical processing is delayed in Broca's aphasia, as compared to lexical processing in healthy listeners. The current proposal undertakes an investigation of the time course of lexical processing in Broca's aphasia by utilizing idiomatic phrases (IPs), which are argued to be long lexical items that have multiple meanings (literal and figurative). For instance, the IP 'hit the sack' is associated with a figurative meaning (i.e. 'to go to sleep'), but each word in this phrase also carries an independent literal meaning (i.e. 'strike' and 'bag'). IPs is used in the current study because prior research with unimpaired listeners indicates that these healthy individuals lexically process both the literal and the figurative meanings of an IP, but on slightly offset time scales. That is, typical listeners begin to lexically process the figurative meaning of an IP slightly prior to lexically processing the literal meaning. This temporal discrepancy motivates the current proposal, and will allow a close examination of the time course of lexical access in Broca's aphasia. This project embeds IPs in auditory sentence contexts and, using on-line methodology, examines moment- by-moment lexical processing in Broca's aphasia for the IP's meanings during auditory comprehension. The goals of this project are: 1) to determine whether lexical processing is delayed for one or both meanings of an IP in Broca's aphasia during auditory sentence comprehension; 2) to question whether lexical items with multiple meanings (i.e. IPs) incite delayed lexical processing, or if lexical processing is inherently delayed; and 3) to investigate off-line comprehension of IPs in Broca's aphasia. The outcomes of the current project will inform theoretical models of language comprehension deficits in Broca's aphasia, by providing insight into the processing mechanisms that underlie these impairments. This project may also inform treatment of Broca's aphasia, by highlighting the specific elements of language (i.e. lexical processing speed) that should be targeted for remediation. PUBLIC HEALTH RELEVANCE: Aphasia, an acquired language disorder that is typically caused by a stroke, may affect over one million individuals in the United States. This disorder can impair the ways in which an individual understands and interacts with those around them, and has significant communicative, emotional, and financial consequences for patients and families. This project seeks to better understand language comprehension impairments in individuals with aphasia, and the findings will ultimately carry implications for treatment of the disorder.