title: Brain correlates of the orientation of auditory spatial attention onto speaker location in a "cocktail-party" situation.
abstract: Successful speech perception in complex auditory scenes with multiple competing speakers requires spatial segregation of auditory streams into perceptually distinct and coherent auditory objects and focusing of attention toward the speaker of interest. Here, we focused on the neural basis of this remarkable capacity of the human auditory system and investigated the spatiotemporal sequence of neural activity within the cortical network engaged in solving the "cocktail-party" problem. Twenty-eight subjects localized a target word in the presence of three competing sound sources. The analysis of the ERPs revealed an anterior contralateral subcomponent of the N2 (N2ac), computed as the difference waveform for targets to the left minus targets to the right. The N2ac peaked at about 500 ms after stimulus onset, and its amplitude was correlated with better localization performance. Cortical source localization for the contrast of left versus right targets at the time of the N2ac revealed a maximum in the region around left superior frontal sulcus and frontal eye field, both of which are known to be involved in processing of auditory spatial information. In addition, a posterior-contralateral late positive subcomponent (LPCpc) occurred at a latency of about 700 ms. Both these subcomponents are potential correlates of allocation of spatial attention to the target under cocktail-party conditions.
authors.affiliation: Department of Cognitive Psychology, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany. joerg.lewald@rub.de.|Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany. joerg.lewald@rub.de.
authors.forename: Jörg
authors.identifier: 0000-0001-9351-0170
authors.initials: J
authors.lastname: Lewald
authors.affiliation: Department of Cognitive Psychology, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany.|Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Hanenberg
authors.affiliation: Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Getzmann
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001288:Attention / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013017:Sound Localization / Q000502:physiology*; D065855:Spatial Processing / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult
keywords: Auditory evoked potentials; Cocktail-party effect; LPC; N2ac; Selective attention; Sound localization