Theta oscillations orchestrate medial temporal lobe and neocortex in remembering autobiographical memories

• Published in: NeuroImage (Orlando, Fla.) Vol. 85; pp. 730 - 737
• Main Authors: Fuentemilla, L., Barnes, G.R., Düzel, E., Levine, B.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.01.2014; Elsevier Limited
• Subjects: Adult; Auditory Perception - physiology; Autobiographical memory; Cues; Female; Humans; Hypotheses; Magnetoencephalography; Male; Medial temporal lobe–neocortical synchrony; Medical imaging; Medical research; Memory, Episodic; Mental Recall - physiology; Neocortex - physiology; Nerve Net - physiology; Neural networks; Semantics; Studies; Temporal Lobe - physiology; Theta rhythm; Theta Rhythm - physiology; Medial temporal lobe–neocortical synchrony; Theta rhythm; Magnetoencephalography; Autobiographical memory
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2013.08.029

Remembering autobiographical events can be associated with detailed visual imagery. The medial temporal lobe (MTL), precuneus and prefrontal cortex are held to jointly enable such vivid retrieval, but how these regions are orchestrated remains unclear. An influential prediction from animal physiology is that neural oscillations in theta frequency may be important. In this experiment, participants prospectively collected audio recordings describing personal autobiographical episodes or semantic knowledge over 2 to 7months. These were replayed as memory retrieval cues while recording brain activity with magnetoencephalography (MEG). We identified a peak of theta power within a left MTL region of interest during both autobiographical and General Semantic retrieval. This MTL region was selectively phase-synchronized with theta oscillations in precuneus and medial prefrontal cortex, and this synchrony was higher during autobiographical as compared to General Semantic knowledge retrieval. Higher synchrony also predicted more detailed visual imagery during retrieval. Thus, theta phase-synchrony orchestrates in humans the MTL with a distributed neocortical memory network when vividly remembering autobiographical experiences. •Personal audio recordings from the past trigger autobiographic memories•Medial temporal lobe and neocortex are orchestrated in theta during recollection•Medial temporal lobe theta synchrony with precuneus and medial prefrontal cortex•The amount of theta synchrony predicts the vividness of autobiographical memories