Center for Advanced Intelligence Project, RIKEN, Chuo-ku, Tokyo, Japan.
PLoS One. 2021 Feb 19;16(2):e0246884. doi: 10.1371/journal.pone.0246884. eCollection 2021.
Language is a result of brain function; thus, impairment in cognitive function can result in language disorders. Understanding the aging of brain functions in terms of language processing is crucial for modern aging societies. Previous studies have shown that language characteristics, such as verbal fluency, are associated with cognitive functions. However, the scaling laws in language in elderly people remain poorly understood. In the current study, we recorded large-scale data of one million words from group conversations among healthy elderly people and analyzed the relationship between spoken language and cognitive functions in terms of scaling laws, namely, Zipf's law and Heaps' law. We found that word patterns followed these scaling laws irrespective of cognitive function, and that the variations in Heaps' exponents were associated with cognitive function. Moreover, variations in Heaps' exponents were associated with the ratio of new words taken from the other participants' speech. These results indicate that the exponents of scaling laws in language are related to cognitive processes.
语言是大脑功能的结果；因此，认知功能的损害可能导致语言障碍。理解语言处理方面大脑功能的老化对于现代老龄化社会至关重要。先前的研究表明，语言特征，如词汇流畅性，与认知功能有关。然而，老年人语言中的标度律仍知之甚少。在本研究中，我们记录了健康老年人小组对话中的百万字大数据，并根据标度律（即齐夫定律和海普斯定律）分析了口语与认知功能之间的关系。我们发现，无论认知功能如何，词汇模式都遵循这些标度律，而海普斯指数的变化与认知功能有关。此外，海普斯指数的变化与从其他参与者言语中获取的新词比例有关。这些结果表明，语言标度律的指数与认知过程有关。
