Bilingual Alzheimer's Disease

 描述(由申请人提供)：本项目调查双语和阿尔茨海默病(AD)对语言和认知加工的共同影响，目的是塑造双语心理语言模型(目标1)，测试AD认知衰退的模型(目标2)，并描述双语AD典型的认知障碍的特征(目标3)。最初5年的资助数据揭示了AD患者双语能力下降的意外模式，并表明在通常用于诊断AD的神经心理测试中，双语者的表现与单一语言者不同。这些结果挑战了AD中的双语和认知衰退模型，这些模型目前还不能解释双语AD的认知变化模式，它们强调了进一步研究影响双语语言处理的因素如何影响双语者AD的呈现。我们考虑了双语语言处理的三个主要解释，以得出对AD双语衰退的预测，同时也旨在确定哪种语言、哪些任务和哪些测试条件产生了患有AD的西班牙语-英语双语者与匹配的认知健康对照组之间最大的差异。作为这一努力的一部分，我们建议将我们对双语广告中语言缺陷的研究从单一的单词产生扩展到连接语音和单词列表记忆的产生。这项研究为AD认知衰退模式提供了一个独特的检验，当结合不同的双语加工模式考虑时，会导致对双语AD中双语变化的不同预测。通过对这些模型的检验，我们的目的是确定哪种认知机制导致双语AD中的语言衰退(语义加工、提取困难或执行控制)，阐明执行控制在双语语言加工中的作用，并可能识别双语对认知衰退的保护作用，以及独一无二的 双语者AD的标志物。每项研究都会使用双语能力的客观衡量方法，研究双语能力如何影响从低水平到高水平的整个连续过程中的表现。该研究将继续一项系统的研究计划，旨在描述双语AD中认知缺陷的典型表现，同时为AD中双语语言处理和认知衰退的模式提供独特的证据。拟议的研究将提供一个理论框架，以制定更好的双语者评估措施，并将进一步的实际意义，通过确定条件，最大限度地减少语言之间的干扰，并允许患有AD的双语者尽可能流利地说话。

 DESCRIPTION (provided by applicant): This project investigates the joint consequences of bilingualism and Alzheimer's disease (AD) for linguistic and cognitive processing, with the goals of shaping psycholinguistic models of bilingualism (Aim 1), testing models of cognitive decline in AD (Aim 2), and characterizing the profile of cognitive impairments typical of bilingual AD (Aim 3). Data from an initial 5 years of funding revealed unexpected patterns of dual-language decline in AD, and suggested that bilinguals perform differently from monolinguals on neuropsychological tests often used to diagnose AD. These results challenge models of bilingualism and cognitive decline in AD, which currently do not account for patterns of cognitive change in bilingual AD, and they underscore the need to further investigate how factors that are known to affect bilingual language processing influence the presentation of AD in bilinguals. We consider three major accounts of bilingual language processing to derive predictions about dual-language decline in AD, while also aiming to identify which language, which tasks, and which testing conditions produce the greatest differences between Spanish-English bilinguals with AD and matched cognitively healthy controls. As a part of this endeavor, we propose to extend our investigation of language deficits in bilingual AD from single word production to also examine production of connected speech and verbal list memory. The proposed studies provide a unique test of models of cognitive decline in AD, which, when considered in concert with different bilingual processing models, lead to different predictions about dual-language change in bilingual AD. By testing these models, we aim to identify which cognitive mechanism is responsible for linguistic decline in bilingual AD (semantic processing, retrieval difficulty, or executive control), to shed light on the role of executive control in bilingual language processing and, possibly, to identify protective effects of bilingualism against cognitive decline, and unique markers of AD in bilinguals. Using objective measures of bilingual language proficiency, each study will examine how bilingualism affects performance across the full continuum from low to high levels of proficiency. The proposed studies will continue a systematic program of research that aims to characterize the typical presentation of cognitive deficits in bilingual AD, while bringing unique evidence to bear on models of bilingual language processing and cognitive decline in AD. The proposed studies will provide a theoretical framework from which to develop better assessment measures for bilinguals, and they will have further practical implications by identifying conditions that minimize interference between languages and allow bilinguals with AD to speak as fluently as they can.