title: Electrophysiological correlates of cocktail-party listening.
abstract: Detecting, localizing, and selectively attending to a particular sound source of interest in complex auditory scenes composed of multiple competing sources is a remarkable capacity of the human auditory system. The neural basis of this so-called "cocktail-party effect" has remained largely unknown. Here, we studied the cortical network engaged in solving the "cocktail-party" problem, using event-related potentials (ERPs) in combination with two tasks demanding horizontal localization of a naturalistic target sound presented either in silence or in the presence of multiple competing sound sources. Presentation of multiple sound sources, as compared to single sources, induced an increased P1 amplitude, a reduction in N1, and a strong N2 component, resulting in a pronounced negativity in the ERP difference waveform (N2d) around 260 ms after stimulus onset. About 100 ms later, the anterior contralateral N2 subcomponent (N2ac) occurred in the multiple-sources condition, as computed from the amplitude difference for targets in the left minus right hemispaces. Cortical source analyses of the ERP modulation, resulting from the contrast of multiple vs. single sources, generally revealed an initial enhancement of electrical activity in right temporo-parietal areas, including auditory cortex, by multiple sources (at P1) that is followed by a reduction, with the primary sources shifting from right inferior parietal lobule (at N1) to left dorso-frontal cortex (at N2d). Thus, cocktail-party listening, as compared to single-source localization, appears to be based on a complex chronology of successive electrical activities within a specific cortical network involved in spatial hearing in complex situations.
authors.affiliation: Auditory Cognitive Neuroscience Laboratory, Department of Cognitive Psychology, Ruhr University Bochum, D‑44780 Bochum, Germany; Leibniz Research Centre for Working Environment and Human Factors, Ardeystraße 67, D‑44139 Dortmund, Germany. Electronic address: joerg.lewald@rub.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Lewald
authors.affiliation: Auditory Cognitive Neuroscience Laboratory, Department of Cognitive Psychology, Ruhr University Bochum, D‑44780 Bochum, Germany; Leibniz Research Centre for Working Environment and Human Factors, Ardeystraße 67, D‑44139 Dortmund, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Getzmann
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology; D001931:Brain Mapping; D004569:Electroencephalography; D055724:Electrophysiological Phenomena / Q000502:physiology; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010296:Parietal Lobe / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013017:Sound Localization / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D062211:Spatio-Temporal Analysis
keywords: Auditory evoked potentials; Auditory scene analysis; Cocktail party effect; Selective spatial attention; Sound localization