Hippocampal-prefrontal theta oscillations support memory integration

Backus, A. R., Schoffelen, J.-M., Szebényi, S., Hanslmayr, S. and Doeller, C. F. (2016) Hippocampal-prefrontal theta oscillations support memory integration. Current Biology, 26(4), pp. 450-457. (doi: 10.1016/j.cub.2015.12.048) (PMID:26832442)

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.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hanslmayr, Professor Simon
• Authors: Backus, A. R., Schoffelen, J.-M., Szebényi, S., Hanslmayr, S., and Doeller, C. F.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Current Biology
• Publisher: Elsevier (Cell Press)
• ISSN: 0960-9822
• ISSN (Online): 1879-0445
• Published Online: 28 January 2016