title: Medial temporal theta state before an event predicts episodic encoding success in humans.
abstract: We report a human electrophysiological brain state that predicts successful memory for events before they occur. Using magnetoencephalographic recordings of brain activity during episodic memory encoding, we show that amplitudes of theta oscillations shortly preceding the onsets of words were higher for later-recalled than for later-forgotten words. Furthermore, single-trial analyses revealed that recall rate in all 24 participants tested increased as a function of increasing prestimulus theta amplitude. This positive correlation was independent of whether participants were preparing for semantic or phonemic stimulus processing, thus likely signifying a memory-related theta state rather than a preparatory task set. Source analysis located this theta state to the medial temporal lobe, a region known to be critical for encoding and recall. These findings provide insight into state-related aspects of memory formation in humans, and open a perspective for improving memory through theta-related brain states.
authors.affiliation: Center for Advanced Imaging and Department of Neurology, Otto von Guericke University, Leipziger Strasse 44, 39120 Magdeburg, Germany. guderians@mail.nih.gov
authors.forename: Sebastian
authors.initials: S
authors.lastname: Guderian
authors.forename: Björn H
authors.initials: BH
authors.lastname: Schott
authors.forename: Alan
authors.initials: A
authors.lastname: Richardson-Klavehn
authors.forename: Emrah
authors.initials: E
authors.lastname: Düzel
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall; D013702:Temporal Lobe / Q000502:physiology*; D013826:Theta Rhythm; D055815:Young Adult