RT Journal Article
SR Electronic
T1 Theta phase synchronization between the human hippocampus and the prefrontal cortex supports learning of unexpected information
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 144634
DO 10.1101/144634
A1 Matthias J. Gruber
A1 Liang-Tien Hsieh
A1 Bernhard P. Staresina
A1 Christian E. Elger
A1 Juergen Fell
A1 Nikolai Axmacher
A1 Charan Ranganath
YR 2017
UL http://biorxiv.org/content/early/2017/05/31/144634.abstract
AB Events that violate predictions are thought to not only modulate activity within the hippocampus and prefrontal cortex, but also to enhance communication between the two regions. Several studies in rodents have shown that synchronized theta oscillations facilitate communication between the prefrontal cortex and hippocampus during salient events, but it remains unclear whether similar oscillatory mechanisms support interactions between the two regions in humans. Here, we had the rare opportunity to conduct simultaneous electrophysiological recordings from the human hippocampus and prefrontal cortex from two patients undergoing presurgical evaluation for pharmaco-resistant epilepsy. Recordings were conducted during a task that involved encoding of contextually expected and unexpected visual stimuli. Across both patients, hippocampal-prefrontal theta phase synchronization was significantly higher during encoding of unexpected study items, compared to contextually expected study items. In contrast, we did not find increased theta synchronization between the prefrontal cortex and rhinal cortex. Our findings are consistent with the idea that theta oscillations orchestrate communication between the hippocampus and prefrontal cortex during the processing of contextually salient information.