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Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech
So-called duplex speech stimuli with perceptually ambiguous spectral cues to one ear and isolated low- vs. high-frequency third formant “chirp” to the opposite ear yield a coherent percept supporting their phonetic categorization. Critically, such dichotic sounds are only perceived categorically upo...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Cold Spring Harbor Laboratory
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10197666/ https://www.ncbi.nlm.nih.gov/pubmed/37214801 http://dx.doi.org/10.1101/2023.05.09.540018 |
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author | Rizzi, Rose Bidelman, Gavin M. |
author_facet | Rizzi, Rose Bidelman, Gavin M. |
author_sort | Rizzi, Rose |
collection | PubMed |
description | So-called duplex speech stimuli with perceptually ambiguous spectral cues to one ear and isolated low- vs. high-frequency third formant “chirp” to the opposite ear yield a coherent percept supporting their phonetic categorization. Critically, such dichotic sounds are only perceived categorically upon binaural integration. Here, we used frequency-following responses (FFRs), scalp-recorded potentials reflecting phase-locked subcortical activity, to investigate brainstem responses to fused speech percepts and to determine whether FFRs reflect binaurally integrated category-level representations. We recorded FFRs to diotic and dichotic stop-consonants (/da/, /ga/) that either did or did not require binaural fusion to properly label along with perceptually ambiguous sounds without clear phonetic identity. Behaviorally, listeners showed clear categorization of dichotic speech tokens confirming they were heard with a fused, phonetic percept. Neurally, we found FFRs were stronger for categorically perceived speech relative to category-ambiguous tokens but also differentiated phonetic categories for both diotically and dichotically presented speech sounds. Correlations between neural and behavioral data further showed FFR latency predicted the degree to which listeners labeled tokens as “da” vs. “ga”. The presence of binaurally integrated, category-level information in FFRs suggests human brainstem processing reflects a surprisingly abstract level of the speech code typically circumscribed to much later cortical processing. |
format | Online Article Text |
id | pubmed-10197666 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | Cold Spring Harbor Laboratory |
record_format | MEDLINE/PubMed |
spelling | pubmed-101976662023-05-20 Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech Rizzi, Rose Bidelman, Gavin M. bioRxiv Article So-called duplex speech stimuli with perceptually ambiguous spectral cues to one ear and isolated low- vs. high-frequency third formant “chirp” to the opposite ear yield a coherent percept supporting their phonetic categorization. Critically, such dichotic sounds are only perceived categorically upon binaural integration. Here, we used frequency-following responses (FFRs), scalp-recorded potentials reflecting phase-locked subcortical activity, to investigate brainstem responses to fused speech percepts and to determine whether FFRs reflect binaurally integrated category-level representations. We recorded FFRs to diotic and dichotic stop-consonants (/da/, /ga/) that either did or did not require binaural fusion to properly label along with perceptually ambiguous sounds without clear phonetic identity. Behaviorally, listeners showed clear categorization of dichotic speech tokens confirming they were heard with a fused, phonetic percept. Neurally, we found FFRs were stronger for categorically perceived speech relative to category-ambiguous tokens but also differentiated phonetic categories for both diotically and dichotically presented speech sounds. Correlations between neural and behavioral data further showed FFR latency predicted the degree to which listeners labeled tokens as “da” vs. “ga”. The presence of binaurally integrated, category-level information in FFRs suggests human brainstem processing reflects a surprisingly abstract level of the speech code typically circumscribed to much later cortical processing. Cold Spring Harbor Laboratory 2023-05-09 /pmc/articles/PMC10197666/ /pubmed/37214801 http://dx.doi.org/10.1101/2023.05.09.540018 Text en https://creativecommons.org/licenses/by/4.0/This work is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/) , which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use. |
spellingShingle | Article Rizzi, Rose Bidelman, Gavin M. Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech |
title | Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech |
title_full | Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech |
title_fullStr | Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech |
title_full_unstemmed | Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech |
title_short | Duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech |
title_sort | duplex perception reveals brainstem auditory representations are modulated by listeners’ ongoing percept for speech |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10197666/ https://www.ncbi.nlm.nih.gov/pubmed/37214801 http://dx.doi.org/10.1101/2023.05.09.540018 |
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