Schedule of Events | Symposia

Understanding the mechanisms of lateral parietal memory modulation in Mild Cognitive Impairment

Poster Session C - Sunday, March 30, 2025, 5:00 – 7:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Matthew Slayton¹ (matthew.slayton@duke.edu), Margaret McAllister², Kirsten Gillette¹, Emily Finch¹, Jane Rothrock¹, Roberto Cabeza¹, Simon Davis¹; ¹Duke University, ²University of North Carolina Chapel Hill

Alzheimer’s Disease is characterized by progressive impairment of cognition and memory, including the loss of episodic memory. An ongoing question in the field of memory neuromodulation is whether the memory benefit of Theta-Burst Stimulation (TBS) occurs in parietal cortex at the stimulation site or downstream in hippocampus. The current project seeks to address how the underlying visual and semantic information coded in the brain changes as a function of a parietal TBS over the course of three repeated TBS and subsequent neuroimaging sessions. We used Representational Similarity Analysis (RSA), to evaluate whether behavioral improvements in perceptual and conceptual memory are driven by the modulation of visual or semantic information in the brain. Consistent with the role of lateral parietal cortex as a hub for the processing of abstract knowledge, we show that semantic (but not visual) representations show greater TMS-related changes in left inferior parietal lobule and are associated with improvements in conceptual memory success. While we found enhanced semantic and visual representations in regions that support vision and memory, this effect applied to both conceptual and perceptual memory performance. These results suggest that lateral parietal TMS enhances the processing of semantic information in a way that supports conceptual memory specifically. We propose that site showing the biggest effect depends on the type of memory, and that both parietal cortex and inferior temporal cortex are affected by the stimulation. Such findings suggest an underlying mechanism by which neuromodulation may improve episodic memory in healthy aging and MCI.

Topic Area: LONG-TERM MEMORY: Episodic