Hippocampal-Prefrontal theta oscillations support memory integration

Research output: Contribution to journalArticlepeer-review

Authors

  • Alexander R Backus
  • Simon Hanslmayr
  • Jan-Mathijs Schoffelen
  • Szabolcs Szebenyi
  • Christian F Doeller

Abstract

Integration of separate memories forms the basis of inferential reasoning—an essential cognitive process that enables complex behavior. Considerable evidence suggests that both hippocampus and medial prefrontal cortex (mPFC) play a crucial role in memory integration. Although previous studies indicate that theta oscillations facilitate memory processes, the electrophysiological mechanisms underlying memory integration remain elusive. To bridge this gap, we recorded magnetoencephalography data while participants performed an inference task and employed novel source reconstruction techniques to estimate oscillatory signals from the hippocampus. We found that hippocampal
theta power during encoding predicts subsequent memory integration. Moreover, we observed increased theta coherence between hippocampus and mPFC. Our results suggest that integrated memory representations arise through hippocampal theta oscillations, possibly reflecting dynamic switching between encoding and retrieval states, and facilitating communication with mPFC. These findings have important implications for our understanding of memory-based decision making and knowledge acquisition.

Bibliographic note

Open access under an Elsevier user licence

Details

Original languageEnglish
Pages (from-to)450–457
JournalCurrent Biology
Volume26
Issue number4
Early online date28 Jan 2016
Publication statusPublished - 22 Feb 2016