Speech Markers of Cognition in Aging Bilingualism

项目摘要/摘要 自发性言语在发音前几年、甚至几十年都会经历微妙而重大的变化 痴呆症。语音或语音标记的变化迹象包括使用句法上更简单的结构， 降低了想法密度，增加了填充词、非特定名词和高频词(Berisha等人， 2015年；斯诺登，1996年)。这些变化对痴呆症的早期诊断有潜在的临床实用价值，而且 更广泛地说，对理解正常和受损的语言产出更感兴趣。建议进行的研究 将在诊断前研究阿尔茨海默病(AD)的语音标记(即，在先兆AD中) 西班牙语-英语双语者。尽管使用两种语言的人使用了两种语言，但在双语者中还没有对言语标记进行研究 语言可能会放大言语产生的认知机制和对前兆的敏感性 广告。双语者可能会表现出单语者没有的独特的言语标记，以及一些相同的标记 作为单一语言的人，但在两种语言之间具有差异敏感性。当双语者说话时，他们必须 选择说哪种语言，并且必须避免来自他们不使用的语言的干扰， 当用相对不太熟练或不占优势的语言(L2)说话时，可能会特别困难。通过 相比之下，至少在某些方面，使用主要语言或L1的语音相对更自动，而且 也指双语者可能具有最高水平的语义知识和语言技能的语言。 第一语言和第二语言之间的这些关键差异导致了对各自言语的哪些方面的不同期望 语言应该对认知衰退最敏感(目标1)，并且与其他语言的相关性最强 认知功能领域(目标2)。为了验证这些假设，在目标1中，我们将检查 在测试时认知健康但多年后发展起来的双语者的自发言语 诊断可能的阿尔茨海默病以确定L1和L2的先兆AD的语言标记。在目标2中，我们将 前瞻性研究母语和二语自发言语标记语与一般认知的关系 功能(通过一系列神经心理测试来衡量)，并将检验时间- 压力图片命名，最近发现的痴呆症风险的言语标记(Stiver等人，2021年)可能是一种 前驱AD的言语标记比无限时命名更好，因为它需要更大的需求 在执行控制方面。通过研究双语者的言语产生和认知能力下降的交集 拟议的研究将为双语模型提供信息，并将独特地阐明执行控制在 更广泛地支持语音生成。这些研究领域之间的交叉也可能导致 改进了在不同人群中早期识别AD的方法。最后，本研究项目将 加强申请人在研究生院的培训，大大增加她从事富有成效的职业生涯的机会 作为一名双语言语病理学家，接受过衰老和阿尔茨海默病研究的专门培训，并拥有 重点关注双语能力，这通常与美国的少数族裔地位有关。

Project Summary/Abstract Spontaneous speech undergoes subtle but significant changes years, or even decades, before the onset of dementia. Signs of change in speech, or speech markers, include the use of syntactically simpler structures, reduced idea density, and more filler words, nonspecific nouns, and higher frequency words (Berisha et al., 2015; Snowdon, 1996). Such changes are potentially useful clinically for early diagnosis of dementia and are more broadly interesting for understanding normal and impaired language production. The proposed studies will investigate speech markers of Alzheimer’s Disease (AD) prior to diagnosis (i.e., in prodromal AD) in Spanish-English bilinguals. Speech markers have not been investigated in bilinguals even though use of two languages might magnify the cognitive mechanisms underlying speech production and sensitivity to prodromal AD. Bilinguals may exhibit unique speech markers not found in monolinguals, and some of the same markers as monolinguals but with differential sensitivity across their two languages. When bilinguals speak, they must choose which language to speak and must avoid interference from the language they are not using, tasks that may be especially difficult when speaking in the relatively less proficient, or non-dominant, language (L2). By contrast, speech in the dominant language, or L1, is relatively more automatic, at least in some aspects, and is also the language in which bilinguals may have their highest level of semantic knowledge and linguistic skill. These key differences between L1 and L2 lead to different expectations about which aspects of speech in each language should be most sensitive to cognitive decline (Aim 1) and most strongly correlated with other domains of cognitive functioning (Aim 2). To test these hypotheses, in Aim 1, we will examine archival data of spontaneous speech in bilinguals who were cognitively healthy at the time of testing but years later developed a diagnosis of Probable AD to identify linguistic markers of prodromal AD in L1 and L2. In Aim 2, we will prospectively examine relationships between L1 and L2 spontaneous speech markers and general cognitive functioning (measured by a battery of neuropsychological tests) and will test the hypothesis that time- pressured picture-naming, a recently identified speech marker of dementia risk (Stiver et al., 2021) may be a better speech marker of prodromal AD than naming with unlimited time because of greater demand it places on executive control. By examining the intersection of speech production and cognitive decline in bilinguals the proposed studies will inform models of bilingualism and will shed unique light on the role of executive control in supporting speech production more generally. The intersection between these fields of study may also lead to improved methods for early identification of AD in a diverse demographic. Lastly, this research project will enhance the applicant’s graduate school training and greatly increase her chances to have a productive career as a bilingual speech-language pathologist with specialized training in research on aging and AD, and with a focus on bilingualism which is often correlated with minority status in the USA.