title: Left Superior Temporal Gyrus Is Coupled to Attended Speech in a Cocktail-Party Auditory Scene.
abstract: Using a continuous listening task, we evaluated the coupling between the listener's cortical activity and the temporal envelopes of different sounds in a multitalker auditory scene using magnetoencephalography and corticovocal coherence analysis. Neuromagnetic signals were recorded from 20 right-handed healthy adult humans who listened to five different recorded stories (attended speech streams), one without any multitalker background (No noise) and four mixed with a "cocktail party" multitalker background noise at four signal-to-noise ratios (5, 0, -5, and -10 dB) to produce speech-in-noise mixtures, here referred to as Global scene. Coherence analysis revealed that the modulations of the attended speech stream, presented without multitalker background, were coupled at ∼0.5 Hz to the activity of both superior temporal gyri, whereas the modulations at 4-8 Hz were coupled to the activity of the right supratemporal auditory cortex. In cocktail party conditions, with the multitalker background noise, the coupling was at both frequencies stronger for the attended speech stream than for the unattended Multitalker background. The coupling strengths decreased as the Multitalker background increased. During the cocktail party conditions, the ∼0.5 Hz coupling became left-hemisphere dominant, compared with bilateral coupling without the multitalker background, whereas the 4-8 Hz coupling remained right-hemisphere lateralized in both conditions. The brain activity was not coupled to the multitalker background or to its individual talkers. The results highlight the key role of listener's left superior temporal gyri in extracting the slow ∼0.5 Hz modulations, likely reflecting the attended speech stream within a multitalker auditory scene.
  
  
  CONCLUSIONS
  When people listen to one person in a "cocktail party," their auditory cortex mainly follows the attended speech stream rather than the entire auditory scene. However, how the brain extracts the attended speech stream from the whole auditory scene and how increasing background noise corrupts this process is still debated. In this magnetoencephalography study, subjects had to attend a speech stream with or without multitalker background noise. Results argue for frequency-dependent cortical tracking mechanisms for the attended speech stream. The left superior temporal gyrus tracked the ∼0.5 Hz modulations of the attended speech stream only when the speech was embedded in multitalker background, whereas the right supratemporal auditory cortex tracked 4-8 Hz modulations during both noiseless and cocktail-party conditions.
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium, Service d'ORL et de chirurgie cervico-faciale, ULB-Hôpital Erasme, Université libre de Bruxelles, 1070 Brussels, Belgium, Marc.Vander.Ghinst@erasme.ulb.ac.be.
authors: Marc
authors: http://orcid.org/0000-0003-1155-5901
authors: M
authors: Vander Ghinst
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium, Brain Research Unit, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, FI-00076-AALTO, Espoo, Finland, and BCBL, Basque Center on Cognition, Brain and Language, 20009 San Sebastian, Spain.
authors: Mathieu
authors: http://orcid.org/0000-0003-1694-5087
authors: M
authors: Bourguignon
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Marc
authors: M
authors: Op de Beeck
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Vincent
authors: V
authors: Wens
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Brice
authors: B
authors: Marty
authors: Service d'ORL et de chirurgie cervico-faciale, ULB-Hôpital Erasme, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Sergio
authors: S
authors: Hassid
authors: Service d'ORL et de chirurgie cervico-faciale, ULB-Hôpital Erasme, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Georges
authors: G
authors: Choufani
authors: Brain Research Unit, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, FI-00076-AALTO, Espoo, Finland, and.
authors: Veikko
authors: V
authors: Jousmäki
authors: Brain Research Unit, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, FI-00076-AALTO, Espoo, Finland, and.
authors: Riitta
authors: R
authors: Hari
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Patrick
authors: P
authors: Van Bogaert
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Serge
authors: S
authors: Goldman
authors: Laboratoire de Cartographie fonctionnelle du Cerveau, UNI-ULB Neuroscience Institute, Université libre de Bruxelles, 1070 Brussels, Belgium.
authors: Xavier
authors: X
authors: De Tiège
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D001288:Attention / Q000502:physiology*; D001303:Auditory Cortex / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D055815:Young Adult
keywords: coherence analysis; magnetoencephalography; speech in noise