This study challenges the conventional psycholinguistic view that the distinction between nouns and verbs is pivotal in understanding language impairments in neurological disorders. Traditional views link frontal brain region damage with verb processing deficits and posterior temporoparietal damage with noun difficulties. However, this perspective is contested by findings from patients with Alzheimer’s disease (pwAD), who show impairments in both word classes despite their typical temporoparietal atrophy. Notably, pwAD tend to use semantically lighter verbs in their speech than healthy individuals. By examining English-speaking pwAD and comparing them with Persian-speaking pwAD, this research aims to demonstrate that language impairments in Alzheimer’s disease (AD) stem from the distributional properties of words within a language rather than distinct neural processing networks for nouns and verbs. We propose that the primary deficit in AD language production is an overreliance on high-frequency words. English has a set of particularly high-frequency verbs that surpass most nouns in usage frequency. Since pwAD tend to use high-frequency words, the byproduct of this word distribution in the English language would be an over-usage of high-frequency verbs. In contrast, Persian features complex verbs with an overall distribution lacking extremely high-frequency verbs like those found in English. As a result, we hypothesize that Persian-speaking pwAD would not have a bias toward the overuse of high-frequency verbs.

中文翻译：

---

阿尔茨海默氏病的语言障碍：英语和波斯语之间的比较表明内容-词频而不是名词-动词的区别

这项研究挑战了传统的心理语言学观点，即名词和动词之间的区别对于理解神经系统疾病中的语言障碍至关重要。传统观点将额叶脑区损伤与动词处理缺陷联系起来，将后颞顶区损伤与名词困难联系起来。然而，这一观点受到阿尔茨海默病 (pwAD) 患者的研究结果的质疑，尽管这些患者有典型的颞顶萎缩，但在这两个词类中均表现出缺陷。值得注意的是，与健康人相比，残疾人在言语中倾向于使用语义较轻的动词。通过检查英语 pwAD 并将其与波斯语 pwAD 进行比较，本研究旨在证明阿尔茨海默病 (AD) 中的语言障碍源于语言中单词的分布特性，而不是名词和动词的不同神经处理网络。我们认为 AD 语言产生的主要缺陷是过度依赖高频词。英语有一组使用频率特别高的动词，其使用频率超过了大多数名词。由于 pwAD 倾向于使用高频词，因此英语中这种词分布的副产品将是高频动词的过度使用。相比之下，波斯语的特点是动词复杂，总体分布缺乏像英语中那样的高频动词。因此，我们假设波斯语 pwAD 不会偏向于过度使用高频动词。