title: Slow-theta power decreases during item-place encoding predict spatial accuracy of subsequent context recall.
abstract: Human hippocampal theta oscillations play a key role in accurate spatial coding. Associative encoding involves similar hippocampal networks but, paradoxically, is also characterized by theta power decreases. Here, we investigated how theta activity relates to associative encoding of place contexts resulting in accurate navigation. Using MEG, we found that slow-theta (2-5Hz) power negatively correlated with subsequent spatial accuracy for virtual contextual locations in posterior hippocampus and other cortical structures involved in spatial cognition. A rare opportunity to simultaneously record MEG and intracranial EEG in an epilepsy patient provided crucial insights: during power decreases, slow-theta in right anterior hippocampus and left inferior frontal gyrus phase-led the left temporal cortex and predicted spatial accuracy. Our findings indicate that decreased slow-theta activity reflects local and long-range neural mechanisms that encode accurate spatial contexts, and strengthens the view that local suppression of low-frequency activity is essential for more efficient processing of detailed information.
authors: Department of Psychology, University of Konstanz, 78464 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78464 Konstanz, Germany. Electronic address: maite.crespo-garcia@uni-konstanz.de.
authors: Maité
authors: M
authors: Crespo-García
authors: Department of Psychology, University of Konstanz, 78464 Konstanz, Germany.
authors: Monika
authors: M
authors: Zeiller
authors: Department of Neurosurgery, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany.
authors: Claudia
authors: C
authors: Leupold
authors: Department of Neurology, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany.
authors: Gernot
authors: G
authors: Kreiselmeyer
authors: Department of Neurosurgery, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany.
authors: Stefan
authors: S
authors: Rampp
authors: Department of Neurology, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany.
authors: Hajo M
authors: HM
authors: Hamer
authors: Department of Psychology, University of Konstanz, 78464 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78464 Konstanz, Germany.
authors: Sarang S
authors: SS
authors: Dalal
mesh_terms: D000328:Adult; D000069280:Electrocorticography / Q000379:methods*; D004827:Epilepsy / Q000503:physiopathology; D005260:Female; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D065854:Spatial Navigation / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*; D055815:Young Adult
keywords: Hippocampus; Intracranial EEG; MEG; Source localization; Spatial navigation