School of Psychology, Speech and Hearing, University of Canterbury, Christchurch, New Zealand.
New Zealand Institute of Language, Brain and Behaviour, University of Canterbury, Christchurch, New Zealand.
PLoS One. 2023 Aug 3;18(8):e0288556. doi: 10.1371/journal.pone.0288556. eCollection 2023.
Alzheimer's disease (AD) is accompanied by language impairments and communicative breakdowns. Research into language processing by people with AD (pwAD) has focused largely on production of nouns in isolation. However, impairments are consistently found in verb production at word and sentence levels, and comparatively little is known about word use by pwAD in conversation. This study investigated differences between pwAD and cognitively healthy controls in conversational use of nouns, verbs, and pronouns. Speech samples produced by 12 pwAD and 12 controls for the Carolinas Conversations Collection were analysed for noun, verb and pronoun counts and ratios, lexical diversity overall and among nouns and verbs, copula use, and frequencies and ages of acquisition (AoA) of nouns and verbs produced. pwAD used fewer nouns and a narrower range of words than controls, exhibiting signs of increased reliance on pronouns and decreased noun diversity. Age affected noun frequencies differently within each group-pwAD produced nouns of lower frequencies with age, while controls produced nouns of higher frequencies. pwAD produced nouns of higher AoA than controls. Verb use differed little by group. These findings highlight the need to account for differences between nouns and verbs, including in frequency, AoA, proportion of all words spoken, and context-dependent processing demands, when drawing conclusions on language use by pwAD. They also suggest potential for communicative interventions targeting contextual use of both nouns and verbs.
阿尔茨海默病（AD）伴有语言障碍和交际障碍。针对 AD 患者（pwAD）语言处理的研究主要集中在孤立名词的生成上。然而，在单词和句子层面，动词生成始终存在障碍，而关于 pwAD 在会话中单词使用的信息相对较少。本研究调查了 pwAD 和认知健康对照组在名词、动词和代词的会话使用方面的差异。分析了 12 名 pwAD 和 12 名对照者为卡罗莱纳语料库收集所产生的言语样本中的名词、动词和代词的数量和比例、整体和名词和动词中的词汇多样性、系动词使用情况，以及名词和动词的出现频率和习得年龄（AoA）。与对照组相比，pwAD 使用的名词更少，词汇范围更窄，表现出对代词的依赖增加和名词多样性降低的迹象。年龄对每个组内名词的频率的影响不同-pwAD 随着年龄的增长产生频率较低的名词，而对照组则产生频率较高的名词。pwAD 产生的名词的 AoA 高于对照组。动词的使用在组间差异不大。这些发现强调了在得出关于 pwAD 的语言使用结论时，需要考虑名词和动词之间的差异，包括频率、AoA、说出的所有单词中的比例以及与上下文相关的处理需求。它们还表明针对名词和动词的上下文使用进行交际干预的潜力。
