Brain-Wide Responses to Item Repetition

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Brandon S. Katerman¹, Ricardo T. Adrogue¹, Daniel Schonhaut¹, Matthew Dougherty¹, Evan A. Snyder¹, Madison Paron¹, James P. Bruska¹, Ryan A. Colyer¹, Michael J. Kahana¹; ¹University of Pennsylvania

Repetition plays a vital role in learning and memory processes across species. Although repetition produces learning, it generates muted neural responses in both perceptual and memory regions. Here, we investigated the neural correlates of repetition across widespread brain regions as subjects perform an episodic memory task. Recording intracranial electroencephalographic (EEG) signals in neurosurgical patients (n=55) revealed repetition-related reductions in high frequency activity (HFA) and increases in low frequency (LFA) activity, consistent with previous studies of repetition suppression. This pattern indicates suppression of oscillatory power that typically accompany successful memory encoding and retrieval. We observed these effects in recordings taken from widespread neocortical regions, as well as in the hippocampus proper. Contrary to predictions of several theories, the degree to which repetition suppressed spectral correlates of successful memory encoding did not reliably predict subsequent memory for the repeated items.

Topic Area: LONG-TERM MEMORY: Episodic