The nature and emergence of lexical difficulties in aging adults

随着年龄的增长，人们越来越难以记住单词。例如，我们可能很难回忆起我们需要的工具的名称或新邻居的名字。这些问题很常见，令人沮丧，会影响一个人的工作和个人生活。令人惊讶的是，在健康老龄化过程中，这些语言能力下降的性质和原因仍然不为人所知。这项研究考察了我们随着年龄增长而经历的语言困难的类型，它们可能出现的时间，以及它们发生的原因。除了解释这些健康衰老的下降，这样的研究可能会导致更好地理解与年龄相关的记忆障碍，以及减轻赤字的潜在策略。本研究的第一个目标是通过对250名年龄在30岁到79岁之间的成年人进行测试，严格地描述在衰老过程中出现的词汇困难类型。所有参与者都将被分配语言任务，旨在评估单词的学习和使用，同时控制参与者之间的潜在差异，例如受教育程度、社会经济地位和参与者学习被测试单词的年龄。该研究的第二个目标是找出随着年龄增长单词发现能力下降的原因。越来越多的证据表明，学习单词依赖于海马体，这是一种已知的更普遍的记忆基础（例如，你把钥匙放在哪里）的大脑结构。因为海马体会随着年龄的增长而急剧萎缩，这也会影响对单词的记忆。为了验证这一解释，将对海马体进行核磁共振扫描，看看海马体的萎缩是否与单词发现能力下降有关。如果海马体的衰退可以解释在衰老过程中发现单词的困难，那么它们也可以解释其他与年龄相关的认知缺陷。高中生、本科生和研究生将接受培训，进一步促进该项目的教育影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

As people get older, they have increasing difficulty remembering words. For example, we might have trouble recalling the name of a tool that we need or the first name of a new neighbor. These problems can be common and frustrating and can impact one’s work personal life. Surprisingly, the nature and causes of these language declines in healthy aging are still not understood. This research examines the types of word difficulties we experience with aging, when they are likely to appear, and why they occur. In addition to explaining these declines in healthy aging, such research may lead to a better understanding of age-related memory disorders together with potential strategies for alleviating the deficits. The first objective of this research is to rigorously characterize what types of lexical difficulties emerge during aging, and when, by testing 250 adults ranging in age from 30 to 79 years. All participants will be given language tasks designed to assess word learning and use, while controlling for potential differences among participants, such as those in education, socioeconomic status, and age at which participants learned the words being tested. The second objective of the research is to find the causes of word-finding declines in aging. Increasing evidence suggests that learning words is dependent on the hippocampus, a brain structure known to underlie memory more generally (e.g., where you put your keys). Because the hippocampus shrinks dramatically with age, this should also affect memory for words. To test this explanation, MRI scans of the hippocampus will be conducted to see if shrinkage of the hippocampus maps to word finding declines. If hippocampal declines explain word finding difficulties in aging, they may also explain other age-related cognitive deficits. High school, undergraduate, and graduate students will be trained, furthering the educational impacts of the project.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.