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Processing of harmonics in the lateral belt of macaque auditory cortex

Many speech sounds and animal vocalizations contain components, referred to as complex tones, that consist of a fundamental frequency (F0) and higher harmonics. In this study we examined single-unit activity recorded in the core (A1) and lateral belt (LB) areas of auditory cortex in two rhesus monke...

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Autores principales: Kikuchi, Yukiko, Horwitz, Barry, Mishkin, Mortimer, Rauschecker, Josef P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4104551/
https://www.ncbi.nlm.nih.gov/pubmed/25100935
http://dx.doi.org/10.3389/fnins.2014.00204
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author Kikuchi, Yukiko
Horwitz, Barry
Mishkin, Mortimer
Rauschecker, Josef P.
author_facet Kikuchi, Yukiko
Horwitz, Barry
Mishkin, Mortimer
Rauschecker, Josef P.
author_sort Kikuchi, Yukiko
collection PubMed
description Many speech sounds and animal vocalizations contain components, referred to as complex tones, that consist of a fundamental frequency (F0) and higher harmonics. In this study we examined single-unit activity recorded in the core (A1) and lateral belt (LB) areas of auditory cortex in two rhesus monkeys as they listened to pure tones and pitch-shifted conspecific vocalizations (“coos”). The latter consisted of complex-tone segments in which F0 was matched to a corresponding pure-tone stimulus. In both animals, neuronal latencies to pure-tone stimuli at the best frequency (BF) were ~10 to 15 ms longer in LB than in A1. This might be expected, since LB is considered to be at a hierarchically higher level than A1. On the other hand, the latency of LB responses to coos was ~10 to 20 ms shorter than to the corresponding pure-tone BF, suggesting facilitation in LB by the harmonics. This latency reduction by coos was not observed in A1, resulting in similar coo latencies in A1 and LB. Multi-peaked neurons were present in both A1 and LB; however, harmonically-related peaks were observed in LB for both early and late response components, whereas in A1 they were observed only for late components. Our results suggest that harmonic features, such as relationships between specific frequency intervals of communication calls, are processed at relatively early stages of the auditory cortical pathway, but preferentially in LB.
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spelling pubmed-41045512014-08-06 Processing of harmonics in the lateral belt of macaque auditory cortex Kikuchi, Yukiko Horwitz, Barry Mishkin, Mortimer Rauschecker, Josef P. Front Neurosci Psychology Many speech sounds and animal vocalizations contain components, referred to as complex tones, that consist of a fundamental frequency (F0) and higher harmonics. In this study we examined single-unit activity recorded in the core (A1) and lateral belt (LB) areas of auditory cortex in two rhesus monkeys as they listened to pure tones and pitch-shifted conspecific vocalizations (“coos”). The latter consisted of complex-tone segments in which F0 was matched to a corresponding pure-tone stimulus. In both animals, neuronal latencies to pure-tone stimuli at the best frequency (BF) were ~10 to 15 ms longer in LB than in A1. This might be expected, since LB is considered to be at a hierarchically higher level than A1. On the other hand, the latency of LB responses to coos was ~10 to 20 ms shorter than to the corresponding pure-tone BF, suggesting facilitation in LB by the harmonics. This latency reduction by coos was not observed in A1, resulting in similar coo latencies in A1 and LB. Multi-peaked neurons were present in both A1 and LB; however, harmonically-related peaks were observed in LB for both early and late response components, whereas in A1 they were observed only for late components. Our results suggest that harmonic features, such as relationships between specific frequency intervals of communication calls, are processed at relatively early stages of the auditory cortical pathway, but preferentially in LB. Frontiers Media S.A. 2014-07-21 /pmc/articles/PMC4104551/ /pubmed/25100935 http://dx.doi.org/10.3389/fnins.2014.00204 Text en Copyright © 2014 Kikuchi, Horwitz, Mishkin and Rauschecker. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Psychology
Kikuchi, Yukiko
Horwitz, Barry
Mishkin, Mortimer
Rauschecker, Josef P.
Processing of harmonics in the lateral belt of macaque auditory cortex
title Processing of harmonics in the lateral belt of macaque auditory cortex
title_full Processing of harmonics in the lateral belt of macaque auditory cortex
title_fullStr Processing of harmonics in the lateral belt of macaque auditory cortex
title_full_unstemmed Processing of harmonics in the lateral belt of macaque auditory cortex
title_short Processing of harmonics in the lateral belt of macaque auditory cortex
title_sort processing of harmonics in the lateral belt of macaque auditory cortex
topic Psychology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4104551/
https://www.ncbi.nlm.nih.gov/pubmed/25100935
http://dx.doi.org/10.3389/fnins.2014.00204
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