Frequency results.

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（Alzheimer’s disease, AD）患者常伴随语言障碍与交际功能受损。当前针对阿尔茨海默病患者（people with AD, pwAD）的语言处理研究，多聚焦于孤立状态下的名词产出。然而，学界一贯发现患者在词汇与语句层面的动词产出存在障碍，而关于患者在自然会话中的词汇使用情况，现有认知仍较为有限。本研究对比了阿尔茨海默病患者与认知健康对照者在会话中对名词、动词及代词的使用差异。研究分析了来自卡罗莱纳会话数据集（Carolinas Conversations Collection）的12名阿尔茨海默病患者与12名对照者的语音样本，统计指标涵盖名词、动词与代词的数量及占比，整体词汇多样性及名词、动词各自的词汇多样性，系动词使用频率，以及产出的名词与动词的使用频率和习得年龄（age of acquisition, AoA）。分析结果显示：相较于对照者，阿尔茨海默病患者使用的名词数量更少，词汇使用范围更窄，表现出对代词的依赖程度升高、名词多样性降低的特征。年龄对两组人群的名词使用频率存在差异化影响：阿尔茨海默病患者随年龄增长所产出名词的频率逐渐降低，而对照者产出的名词频率则随年龄有所升高。此外，阿尔茨海默病患者产出的名词习得年龄高于对照者，而两组在动词使用上的差异较小。上述研究结果凸显了在针对阿尔茨海默病患者的语言使用得出结论时，需充分考量名词与动词在使用频率、习得年龄、词汇总占比以及语境依赖的加工需求等方面的差异。本研究同时提示，可针对名词与动词的语境化使用开发相应的交际干预方案。