The nature and emergence of lexical difficulties in aging adults

Georgetown University, Washington DC

Investigators

Abstract

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.