Poster F80, Tuesday, March 28, 8:00 – 10:00 am, Pacific Concourse
Improving Memory by Biasing Awake Memory Reactivation
Kylie H. Alm1, Chi T. Ngo1, Ingrid R. Olson1; 1Temple University
Why are some memories easy to retrieve, while others are more difficult to access? Here, we asked whether you can bias memory replay, a process whereby newly learned information is reinforced by reinstating the neuronal patterns of activation that were present during learning, towards particular memory traces. The goal of this biasing is to strengthen some memory traces, making them more easily retrieved. To test this, participants were scanned during interleaved encoding and resting state runs. Throughout the encoding runs, participants learned triplets of images that were paired with semantically related sound cues. During two of the three 8.5-minute resting state runs, irrelevant sounds were played. During one key rest period, however, the sound cues learned in the preceding encoding period were played in an effort to increase reactivation of the associated visual images, e.g. targeted reactivation. Memory was tested after scanning and a 24-hour delay. Results revealed that items that underwent targeted reactivation during post-encoding rest periods were remembered better than untargeted items. For the fMRI data, representational similarity analyses were used to compare multi-voxel patterns of hippocampal activation across encoding and rest periods. Hippocampal patterns exhibited increased pattern similarity when comparing the critical encoding set to its subsequently cued sound rest period, relative to baseline rest. Furthermore, there was a positive relationship between this neural evidence of replay and the magnitude of the behavioral cueing effect, suggesting that preferential replay may be a mechanism by which specific memory traces can be selectively strengthened for enhanced subsequent memory retrieval.
Topic Area: LONG-TERM MEMORY: Episodic