Neural Correlates Underlying the Effect of Temporal Proximity on Associative Memory Retrieval for Older Versus Younger Adults
Open Access
- Author:
- Onwumbiko, Bianka
- Millennium Scholars Program:
- Biology (BIOL)
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisor:
- Nancy Anne Coulter Dennis, Thesis Supervisor
- Keywords:
- associative memory; aging; fMRI
- Abstract:
- Associative memory is a vital component of everyday memory, and success in this form of memory is dependent on one’s ability to limit attention and inhibit irrelevant information. Previous behavioral research has shown that older adults exhibit deficits in this ability compared to younger adults (Dennis and McCormick-Huhn, 2018), and this age-related discrepancy is exacerbated as the two target items are presented closer together in time (Campbell and Hasher, 2014). In this study, we aimed to replicate these behavioral findings as we hypothesized that when completing an associative memory task, older adults would exhibit higher false alarm rates than younger adults for near re-pairings (n ≤ 9 positions apart) compared to far re-pairings (n > 9 positions apart), and that younger adults would exhibit lower overall false alarm rates. The current study utilized functional magnetic resonance imaging (fMRI) to determine the neural correlates underlying the effect of temporal proximity on associative memory retrieval for older versus younger adults. Due to the role of the medial temporal lobe in the retrieval of associative memories and the role of the prefrontal cortex in the inhibition of irrelevant information, we hypothesized that older adults would exhibit increased brain activity in these regions compared to younger adults for near versus far re-pairings. We found that younger adults did in fact exhibit lower overall false alarm rates than older adults (p < 0.001). However, the age-related behavioral difference associated with the effect of temporal proximity was insignificant. Nonetheless, we did find differences in neural activity between the near and far temporal proximity conditions in older and younger adults, suggesting that older adults utilize different neural strategies than younger adults when overcoming the effect of temporal proximity on associative memory retrieval.