Search Abstracts | Symposia | Slide Sessions | Poster Sessions
Our difficulty remembering new words as we get older may be driven by hippocampal atrophy
Poster Session A, Friday, September 12, 11:00 am - 12:30 pm, Field House
Joshua Buffington1, Michael Ullman1, Jana Reifegerste1; 1Georgetown University
Although word learning is important during childhood, it continues throughout our lives (sudoku, Wegovy, your new neighbor’s name). However, it remains unclear just how aging affects learning and remembering new words and how this is impacted by age-related neural declines. We examined these issues in a cross-sectional continuous-age study (N=191) of participants aged 18-85. Participants saw and heard new words (concrete nouns) together with picture referents, and were then tested on recall (name a word from its picture) and comprehension (match one of two pictures with a word). Gray matter volumes were segmented from whole-brain and high-resolution-hippocampal MRI scans. Given the striking hippocampal atrophy in aging, and evidence implicating the hippocampus in learning and recalling (“recollecting”) associations, we hypothesized that hippocampal atrophy may contribute to age-related declines of word learning, perhaps especially at then recalling these words. Preliminary analyses revealed the following. First, the recall but not comprehension (which does not require recollection) of newly-learned words showed significant age-related declines. Second, the recall declines were (marginally significantly) mediated by volumes of the hippocampus but not of frontal- or temporal-lobe control structures. Third, within the hippocampus, several hippocampal subfields appear to play a role in the declines, including the dentate gyrus, CA1, and CA3, all of which have been implicated in learning or recall. In summary, as one ages it appears that one’s ability to learn new words and then understand them does not clearly decline. However, recalling newly-learned words does decline with age. These declines may be driven by the hippocampus, a structure not traditionally tied to language. The study further reveals that particular hippocampal subfields contribute to these declines, potentially advancing our understanding of the fine-grained neural bases of language. The study suggests that word-learning declines in aging may benefit from interventions targeting the hippocampus (e.g., exercise, pharmacological agents).
Topic Areas: Meaning: Lexical Semantics,