Schedule of Events | Symposia

Distributed Functional Networks Associated with Age-Related Decline in High-Fidelity Memory Retrieval

Poster Session B - Sunday, March 30, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Joseph C. C. Chen¹, Adam Gazzaley¹, Peter E. Wais¹; ¹University of California San Francisco

Fidelity of detailed information retrieved from long-term memory (LTM) declines in normal aging. This decline is related to changes in cognitive function that affect learning and remembering processes. Such behavioral deficits have been associated with alterations in the function of the dentate gyrus and CA3 regions of the hippocampus. It is not clear, however, how such aging-related decline in high-fidelity retrieval is associated with functional networks between hippocampal and cortical regions in healthy older brains. Twenty-two cognitively intact older adults (69.4 ± 4.4 years) completed a mnemonic discrimination task where participants indicated whether previously encoded targets, lures, or novel objects were old or new during functional MRI (fMRI) scans. Participants’ high-fidelity memory, as measured by the lure discrimination index (LDI), was on average, 0.49 ± 0.03 – lower than previously reported LDIs in healthy young adults: 0.56 ± 0.04. High-fidelity LTM processes in older adults were implicated in bilateral hippocampal regions, and trial-wise beta-series correlation from the bilateral hippocampal regions engaged functional networks involving bilateral inferior frontal gyri, the right angular gyrus, and bilateral precuneus. Taken together, we characterize the broad distribution of hippocampal-cortical networks in older adults that underlie high-fidelity memory.

Topic Area: LONG-TERM MEMORY: Development & aging