title: Conscious auditory perception related to long-range synchrony of gamma oscillations.
abstract: While the role of synchronized oscillatory activity in the gamma-band frequency range for conscious perception is well established in the visual domain, there is limited evidence concerning neurophysiological mechanisms in conscious auditory perception. In the current study, we addressed this issue with 64-channel EEG and a dichotic listening (DL) task in twenty-five healthy participants. The typical finding of DL is a more frequent conscious perception of the speech syllable presented to the right ear (RE), which is attributed to the supremacy of the contralateral pathways running from the RE to the speech-dominant left hemisphere. In contrast, the left ear (LE) input initially accesses the right hemisphere and needs additional transfer via interhemispheric pathways before it is processed in the left hemisphere. Using lagged phase synchronization (LPS) analysis and eLORETA source estimation we examined the functional connectivity between right and left primary and secondary auditory cortices in the main frequency bands (delta, theta, alpha, beta, gamma) during RE/LE-reports. Interhemispheric LPS between right and left primary and secondary auditory cortices was specifically increased in the gamma-band range, when participants consciously perceived the syllable presented to the LE. Our results suggest that synchronous gamma oscillations are involved in interhemispheric transfer of auditory information.
authors.affiliation: Psychiatry Neuroimaging Branch, Department of Psychiatry and Psychotherapy, University Medical Center Hamburg - Eppendorf, Hamburg, Germany.
authors.forename: Saskia
authors.initials: S
authors.lastname: Steinmann
authors.affiliation: Psychiatry Neuroimaging Branch, Department of Psychiatry and Psychotherapy, University Medical Center Hamburg - Eppendorf, Hamburg, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Leicht
authors.affiliation: Psychiatry Neuroimaging Branch, Department of Psychiatry and Psychotherapy, University Medical Center Hamburg - Eppendorf, Hamburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Ertl
authors.affiliation: Psychiatry Neuroimaging Branch, Department of Psychiatry and Psychotherapy, University Medical Center Hamburg - Eppendorf, Hamburg, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Andreou
authors.affiliation: Psychiatry Neuroimaging Branch, Department of Psychiatry and Psychotherapy, University Medical Center Hamburg - Eppendorf, Hamburg, Germany.
authors.forename: Nenad
authors.initials: N
authors.lastname: Polomac
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; Division of Psychiatry, Haukeland Hospital, Bergen, Norway.
authors.forename: René
authors.initials: R
authors.lastname: Westerhausen
authors.affiliation: Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neuropsychology, Leipzig, Germany.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Friederici
authors.affiliation: Psychiatry Neuroimaging Branch, Department of Psychiatry and Psychotherapy, University Medical Center Hamburg - Eppendorf, Hamburg, Germany. Electronic address: c.mulert@uke.uni-hamburg.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Mulert
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D003243:Consciousness / Q000502:physiology*; D004007:Dichotic Listening Tests; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D065818:Gamma Rhythm / Q000502:physiology*; D006801:Humans; D008297:Male; D013997:Time Factors
keywords: Auditory cortex; Dichotic listening task; EEG; Functional connectivity; Gamma; Interhemispheric auditory pathways; eLORETA