Gordon Jean K, Young Megan, Garcia Carly
a Communication Sciences & Disorders , University of Iowa , Iowa City , IA , USA.
Neuropsychol Dev Cogn B Aging Neuropsychol Cogn. 2018 Nov;25(6):803-828. doi: 10.1080/13825585.2017.1374328. Epub 2017 Sep 6.
Aging involves many cognitive declines, particularly in fluid intelligence, with relative maintenance of crystallized intelligence. This paradox is evident in the language domain: lexical retrieval becomes slower and less accurate, despite well preserved vocabularies. Verbal fluency assesses both crystallized and fluid aspects of language. Semantic fluency hypothetically reflects semantic knowledge, while letter fluency putatively reflects executive functioning, which would predict a greater impact of aging on the latter. However, the opposite is typically observed. To investigate factors contributing to such asymmetries, we examined verbal fluency in 86 adults (30-89 years). Multiple regression analyses indicated that semantic fluency depends largely on lexical retrieval speed, as well as visualization strategies to support controlled retrieval, skills which may disproportionately decline with age. By contrast, letter fluency relies heavily on vocabulary knowledge, providing some protection against age-related declines. These findings contribute to our understanding of the mechanisms of typical age-related declines in word retrieval.
衰老涉及许多认知能力的下降，尤其是在流体智力方面，而晶体智力则相对保持稳定。这种矛盾在语言领域很明显：尽管词汇量保持良好，但词汇检索变得更慢且准确性更低。言语流畅性评估语言的晶体和流体两个方面。语义流畅性假设反映语义知识，而字母流畅性据推测反映执行功能，这将预示衰老对后者有更大影响。然而，通常观察到的情况却相反。为了研究导致这种不对称的因素，我们对86名成年人（30至89岁）的言语流畅性进行了检查。多元回归分析表明，语义流畅性在很大程度上取决于词汇检索速度以及支持控制性检索的视觉化策略，这些技能可能会随着年龄增长而不成比例地下降。相比之下，字母流畅性严重依赖词汇知识，从而为抵御与年龄相关的下降提供了一些保护。这些发现有助于我们理解单词检索中典型的与年龄相关下降的机制。
