title: Cortical networks dynamically emerge with the interplay of slow and fast oscillations for memory of a natural scene.
abstract: Neural oscillations are crucial for revealing dynamic cortical networks and for serving as a possible mechanism of inter-cortical communication, especially in association with mnemonic function. The interplay of the slow and fast oscillations might dynamically coordinate the mnemonic cortical circuits to rehearse stored items during working memory retention. We recorded simultaneous EEG-fMRI during a working memory task involving a natural scene to verify whether the cortical networks emerge with the neural oscillations for memory of the natural scene. The slow EEG power was enhanced in association with the better accuracy of working memory retention, and accompanied cortical activities in the mnemonic circuits for the natural scene. Fast oscillation showed a phase-amplitude coupling to the slow oscillation, and its power was tightly coupled with the cortical activities for representing the visual images of natural scenes. The mnemonic cortical circuit with the slow neural oscillations would rehearse the distributed natural scene representations with the fast oscillation for working memory retention. The coincidence of the natural scene representations could be obtained by the slow oscillation phase to create a coherent whole of the natural scene in the working memory.
authors.affiliation: Graduate School of Informatics, Kyoto University, Yoshida-Honmachi, Sakyo, Kyoto 606-8501, Japan. Electronic address: hmizu@i.kyoto-u.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mizuhara
authors.affiliation: School of Systems Information Science, Future University Hakodate, 116-2 Kamedanakano, Hakodate, Hokkaido 041-8655, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Sato
authors.affiliation: Neuroinformatics Japan Center, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yamaguchi
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D059907:Functional Neuroimaging / Q000379:methods*; D065818:Gamma Rhythm / Q000502:physiology*; D006801:Humans; D007092:Imagination; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D064847:Multimodal Imaging; D009415:Nerve Net / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*; D055815:Young Adult
keywords: Episodic memory; Gamma oscillation; Phase-amplitude coupling; Simultaneous fMRI–EEG; Theta oscillation