title: Spectral fingerprints of large-scale cortical dynamics during ambiguous motion perception.
abstract: Ambiguous stimuli have been widely used to study the neuronal correlates of consciousness. Recently, it has been suggested that conscious perception might arise from the dynamic interplay of functionally specialized but widely distributed cortical areas. While previous research mainly focused on phase coupling as a correlate of cortical communication, more recent findings indicated that additional coupling modes might coexist and possibly subserve distinct cortical functions. Here, we studied two coupling modes, namely phase and envelope coupling, which might differ in their origins, putative functions and dynamics. Therefore, we recorded 128-channel EEG while participants performed a bistable motion task and utilized state-of-the-art source-space connectivity analysis techniques to study the functional relevance of different coupling modes for cortical communication. Our results indicate that gamma-band phase coupling in extrastriate visual cortex might mediate the integration of visual tokens into a moving stimulus during ambiguous visual stimulation. Furthermore, our results suggest that long-range fronto-occipital gamma-band envelope coupling sustains the horizontal percept during ambiguous motion perception. Additionally, our results support the idea that local parieto-occipital alpha-band phase coupling controls the inter-hemispheric information transfer. These findings provide correlative evidence for the notion that synchronized oscillatory brain activity reflects the processing of sensory input as well as the information integration across several spatiotemporal scales. The results indicate that distinct coupling modes are involved in different cortical computations and that the rich spatiotemporal correlation structure of the brain might constitute the functional architecture for cortical processing and specific multi-site communication. Hum Brain Mapp 37:4099-4111, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany. r.helfrich@uke.de.|Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California. r.helfrich@uke.de.
authors.forename: Randolph F
authors.initials: RF
authors.lastname: Helfrich
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Hannah
authors.initials: H
authors.lastname: Knepper
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Nolte
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Sengelmann
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.|Institute of Cognitive Science, University of Osnabrück, Osnabrück, 49069, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: König
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Till R
authors.initials: TR
authors.lastname: Schneider
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Engel
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001921:Brain / Q000502:physiology*; D005260:Female; D065818:Gamma Rhythm; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: EEG source analysis; ambiguous perception; amplitude envelope correlations; bistable perception; gamma oscillations; intrinsic coupling modes; large-scale neuronal networks; motion quartett; phase synchronization; stroboscopic alternative motion