The effects of targeted reactivation on memories cued once or multiple times during a nap

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

Matthew Cho¹, Sandhya Murugavel¹, Alison S. Thiha¹, Eitan Schechtman¹; ¹Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, USA

During sleep, memory traces are reactivated and consolidated into long term memory. Targeted memory reactivation is a technique used to selectively bias reactivation for certain memories by presenting non-invasive sensory cues. We tested whether the number of times a cue was presented during sleep would impact the incurred benefit. Participants (N=31) completed a computerized object-location task, in which 60 images were presented along with related sounds. Participants first learned to associate the sound and image, and then memorized their location on a grid. During non-REM sleep, 40 of these sounds were presented either once (20 sounds) or five times (20 sounds) in an interleaved fashion. The remaining 20 sounds were not presented during sleep. Participants then completed another spatial task, which was designed to interfere with the previously encoded spatial memories, before finally being tested again on the initial object positions. The results showed no significant performance benefits for cued objects regardless of the number of sound presentations. This may be due to the interference task, which substantially increased post-sleep error rates. Nevertheless, we did find differences between the electrophysiological profiles linked with multiple vs. single sound presentation during sleep. Spindle spectral power predicted improvements in performance for the objects cued five times, but not for those cued once. For sounds presented once, post-cue power corresponding to slow wave activity was higher for those linked with objects that benefited more over sleep. Our results inform future research using targeted memory reactivation to selectively bias memory during sleep.

Topic Area: LONG-TERM MEMORY: Episodic