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Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm

Humans routinely segregate a complex acoustic scene into different auditory streams, through the extraction of bottom-up perceptual cues and the use of top-down selective attention. To determine the neural mechanisms underlying this process, neural responses obtained through magnetoencephalography (...

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Autores principales: Akram, Sahar, Englitz, Bernhard, Elhilali, Mounya, Simon, Jonathan Z., Shamma, Shihab A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4260833/
https://www.ncbi.nlm.nih.gov/pubmed/25490720
http://dx.doi.org/10.1371/journal.pone.0114427
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author Akram, Sahar
Englitz, Bernhard
Elhilali, Mounya
Simon, Jonathan Z.
Shamma, Shihab A.
author_facet Akram, Sahar
Englitz, Bernhard
Elhilali, Mounya
Simon, Jonathan Z.
Shamma, Shihab A.
author_sort Akram, Sahar
collection PubMed
description Humans routinely segregate a complex acoustic scene into different auditory streams, through the extraction of bottom-up perceptual cues and the use of top-down selective attention. To determine the neural mechanisms underlying this process, neural responses obtained through magnetoencephalography (MEG) were correlated with behavioral performance in the context of an informational masking paradigm. In half the trials, subjects were asked to detect frequency deviants in a target stream, consisting of a rhythmic tone sequence, embedded in a separate masker stream composed of a random cloud of tones. In the other half of the trials, subjects were exposed to identical stimuli but asked to perform a different task—to detect tone-length changes in the random cloud of tones. In order to verify that the normalized neural response to the target sequence served as an indicator of streaming, we correlated neural responses with behavioral performance under a variety of stimulus parameters (target tone rate, target tone frequency, and the “protection zone”, that is, the spectral area with no tones around the target frequency) and attentional states (changing task objective while maintaining the same stimuli). In all conditions that facilitated target/masker streaming behaviorally, MEG normalized neural responses also changed in a manner consistent with the behavior. Thus, attending to the target stream caused a significant increase in power and phase coherence of the responses in recording channels correlated with an increase in the behavioral performance of the listeners. Normalized neural target responses also increased as the protection zone widened and as the frequency of the target tones increased. Finally, when the target sequence rate increased, the buildup of the normalized neural responses was significantly faster, mirroring the accelerated buildup of the streaming percepts. Our data thus support close links between the perceptual and neural consequences of the auditory stream segregation.
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spelling pubmed-42608332014-12-15 Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm Akram, Sahar Englitz, Bernhard Elhilali, Mounya Simon, Jonathan Z. Shamma, Shihab A. PLoS One Research Article Humans routinely segregate a complex acoustic scene into different auditory streams, through the extraction of bottom-up perceptual cues and the use of top-down selective attention. To determine the neural mechanisms underlying this process, neural responses obtained through magnetoencephalography (MEG) were correlated with behavioral performance in the context of an informational masking paradigm. In half the trials, subjects were asked to detect frequency deviants in a target stream, consisting of a rhythmic tone sequence, embedded in a separate masker stream composed of a random cloud of tones. In the other half of the trials, subjects were exposed to identical stimuli but asked to perform a different task—to detect tone-length changes in the random cloud of tones. In order to verify that the normalized neural response to the target sequence served as an indicator of streaming, we correlated neural responses with behavioral performance under a variety of stimulus parameters (target tone rate, target tone frequency, and the “protection zone”, that is, the spectral area with no tones around the target frequency) and attentional states (changing task objective while maintaining the same stimuli). In all conditions that facilitated target/masker streaming behaviorally, MEG normalized neural responses also changed in a manner consistent with the behavior. Thus, attending to the target stream caused a significant increase in power and phase coherence of the responses in recording channels correlated with an increase in the behavioral performance of the listeners. Normalized neural target responses also increased as the protection zone widened and as the frequency of the target tones increased. Finally, when the target sequence rate increased, the buildup of the normalized neural responses was significantly faster, mirroring the accelerated buildup of the streaming percepts. Our data thus support close links between the perceptual and neural consequences of the auditory stream segregation. Public Library of Science 2014-12-09 /pmc/articles/PMC4260833/ /pubmed/25490720 http://dx.doi.org/10.1371/journal.pone.0114427 Text en © 2014 Akram et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Akram, Sahar
Englitz, Bernhard
Elhilali, Mounya
Simon, Jonathan Z.
Shamma, Shihab A.
Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm
title Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm
title_full Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm
title_fullStr Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm
title_full_unstemmed Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm
title_short Investigating the Neural Correlates of a Streaming Percept in an Informational-Masking Paradigm
title_sort investigating the neural correlates of a streaming percept in an informational-masking paradigm
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4260833/
https://www.ncbi.nlm.nih.gov/pubmed/25490720
http://dx.doi.org/10.1371/journal.pone.0114427
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