title: Long-distance amplitude correlations in the high γ band reveal segregation and integration within the reading network.
abstract: Reading sentences involves a distributed network of brain regions acting in concert surrounding the left sylvian fissure. The mechanisms of neural communication underlying the extraction and integration of verbal information across subcomponents of this reading network are still largely unknown. We recorded intracranial EEG activity in 12 epileptic human patients performing natural sentence reading and analyzed long-range corticocortical interactions between local neural activations. During a simple task contrasting semantic, phonological, and purely visual processes, we found process-specific neural activity elicited at the single-trial level, characterized by energy increases in a broad gamma band (40-150 Hz). Correlation analysis between task-induced gamma-band activations revealed a selective fragmentation of the network into specialized subnetworks supporting sentence-level semantic analysis and phonological processing. We extend the implications of our results beyond reading, to propose that gamma-band amplitude correlations might constitute a fundamental mechanism for large-scale neural integration during high-level cognition.
authors.affiliation: INSERM 1028, CNRS UMR 5292, Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center, University Claude Bernard Lyon 1, F-69500 Bron, France. juan.vidal@inserm.fr
authors.forename: Juan R
authors.initials: JR
authors.lastname: Vidal
authors.forename: Samson
authors.initials: S
authors.lastname: Freyermuth
authors.forename: Karim
authors.initials: K
authors.lastname: Jerbi
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Hamamé
authors.forename: Tomas
authors.initials: T
authors.lastname: Ossandon
authors.forename: Olivier
authors.initials: O
authors.lastname: Bertrand
authors.forename: Lorella
authors.initials: L
authors.lastname: Minotti
authors.forename: Philippe
authors.initials: P
authors.lastname: Kahane
authors.forename: Alain
authors.initials: A
authors.lastname: Berthoz
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lachaux
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D058256:Brain Waves / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D004569:Electroencephalography / Q000379:methods; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology*; D011932:Reading; D055815:Young Adult