title: Speech rhythms and multiplexed oscillatory sensory coding in the human brain.
abstract: Cortical oscillations are likely candidates for segmentation and coding of continuous speech. Here, we monitored continuous speech processing with magnetoencephalography (MEG) to unravel the principles of speech segmentation and coding. We demonstrate that speech entrains the phase of low-frequency (delta, theta) and the amplitude of high-frequency (gamma) oscillations in the auditory cortex. Phase entrainment is stronger in the right and amplitude entrainment is stronger in the left auditory cortex. Furthermore, edges in the speech envelope phase reset auditory cortex oscillations thereby enhancing their entrainment to speech. This mechanism adapts to the changing physical features of the speech envelope and enables efficient, stimulus-specific speech sampling. Finally, we show that within the auditory cortex, coupling between delta, theta, and gamma oscillations increases following speech edges. Importantly, all couplings (i.e., brain-speech and also within the cortex) attenuate for backward-presented speech, suggesting top-down control. We conclude that segmentation and coding of speech relies on a nested hierarchy of entrained cortical oscillations.
authors.affiliation: Institute for Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Joachim
authors.initials: J
authors.lastname: Gross
authors.affiliation: Institute for Clinical Neuroscience and Medical Psychology, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Nienke
authors.initials: N
authors.lastname: Hoogenboom
authors.affiliation: Institute for Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Gregor
authors.initials: G
authors.lastname: Thut
authors.affiliation: Institute for Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Philippe
authors.initials: P
authors.lastname: Schyns
authors.affiliation: Institute for Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom ; Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia @UniTn, Rovereto, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Panzeri
authors.affiliation: Institute for Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Pascal
authors.initials: P
authors.lastname: Belin
authors.affiliation: Institute for Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Garrod
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000502:physiology; D001921:Brain / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D013060:Speech / Q000502:physiology; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult