Cargando…

A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex

Harmonic sounds, such as voiced speech sounds and many animal communication signals, are characterized by a pitch related to the periodicity of their envelopes. While frequency information is extracted by mechanical filtering of the cochlea, periodicity information is analyzed by temporal filter mec...

Descripción completa

Detalles Bibliográficos
Autores principales: Langner, Gerald, Dinse, Hubert R., Godde, Ben
Formato: Texto
Lenguaje:English
Publicado: Frontiers Research Foundation 2009
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784045/
https://www.ncbi.nlm.nih.gov/pubmed/19949464
http://dx.doi.org/10.3389/neuro.07.027.2009
_version_ 1782174705686413312
author Langner, Gerald
Dinse, Hubert R.
Godde, Ben
author_facet Langner, Gerald
Dinse, Hubert R.
Godde, Ben
author_sort Langner, Gerald
collection PubMed
description Harmonic sounds, such as voiced speech sounds and many animal communication signals, are characterized by a pitch related to the periodicity of their envelopes. While frequency information is extracted by mechanical filtering of the cochlea, periodicity information is analyzed by temporal filter mechanisms in the brainstem. In the mammalian auditory midbrain envelope periodicity is represented in maps orthogonal to the representation of sound frequency. However, how periodicity is represented across the cortical surface of primary auditory cortex (AI) remains controversial. Using optical recording of intrinsic signals, we here demonstrate that a periodicity map exists in primary AI of the cat. While pure tone stimulation confirmed the well-known frequency gradient along the rostro-caudal axis of AI, stimulation with harmonic sounds revealed segregated bands of activation, indicating spatially localized preferences to specific periodicities along a dorso-ventral axis, nearly orthogonal to the tonotopic gradient. Analysis of the response locations revealed an average gradient of − 100° ± 10° for the periodotopic, and −12° ± 18° for the tonotopic map resulting in a mean angle difference of 88°. The gradients were 0.65 ± 0.08 mm/octave for periodotopy and 1.07 ± 0.16 mm/octave for tonotopy indicating that more cortical territory is devoted to the representation of an octave along the tonotopic than along the periodotopic gradient. Our results suggest that the fundamental importance of pitch, as evident in human perception, is also reflected in the layout of cortical maps and that the orthogonal spatial organization of frequency and periodicity might be a more general cortical organization principle.
format Text
id pubmed-2784045
institution National Center for Biotechnology Information
language English
publishDate 2009
publisher Frontiers Research Foundation
record_format MEDLINE/PubMed
spelling pubmed-27840452009-11-30 A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex Langner, Gerald Dinse, Hubert R. Godde, Ben Front Integr Neurosci Neuroscience Harmonic sounds, such as voiced speech sounds and many animal communication signals, are characterized by a pitch related to the periodicity of their envelopes. While frequency information is extracted by mechanical filtering of the cochlea, periodicity information is analyzed by temporal filter mechanisms in the brainstem. In the mammalian auditory midbrain envelope periodicity is represented in maps orthogonal to the representation of sound frequency. However, how periodicity is represented across the cortical surface of primary auditory cortex (AI) remains controversial. Using optical recording of intrinsic signals, we here demonstrate that a periodicity map exists in primary AI of the cat. While pure tone stimulation confirmed the well-known frequency gradient along the rostro-caudal axis of AI, stimulation with harmonic sounds revealed segregated bands of activation, indicating spatially localized preferences to specific periodicities along a dorso-ventral axis, nearly orthogonal to the tonotopic gradient. Analysis of the response locations revealed an average gradient of − 100° ± 10° for the periodotopic, and −12° ± 18° for the tonotopic map resulting in a mean angle difference of 88°. The gradients were 0.65 ± 0.08 mm/octave for periodotopy and 1.07 ± 0.16 mm/octave for tonotopy indicating that more cortical territory is devoted to the representation of an octave along the tonotopic than along the periodotopic gradient. Our results suggest that the fundamental importance of pitch, as evident in human perception, is also reflected in the layout of cortical maps and that the orthogonal spatial organization of frequency and periodicity might be a more general cortical organization principle. Frontiers Research Foundation 2009-11-16 /pmc/articles/PMC2784045/ /pubmed/19949464 http://dx.doi.org/10.3389/neuro.07.027.2009 Text en Copyright © 2009 Langner, Dinse and Godde. http://www.frontiersin.org/licenseagreement This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
spellingShingle Neuroscience
Langner, Gerald
Dinse, Hubert R.
Godde, Ben
A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex
title A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex
title_full A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex
title_fullStr A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex
title_full_unstemmed A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex
title_short A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex
title_sort map of periodicity orthogonal to frequency representation in the cat auditory cortex
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784045/
https://www.ncbi.nlm.nih.gov/pubmed/19949464
http://dx.doi.org/10.3389/neuro.07.027.2009
work_keys_str_mv AT langnergerald amapofperiodicityorthogonaltofrequencyrepresentationinthecatauditorycortex
AT dinsehubertr amapofperiodicityorthogonaltofrequencyrepresentationinthecatauditorycortex
AT goddeben amapofperiodicityorthogonaltofrequencyrepresentationinthecatauditorycortex
AT langnergerald mapofperiodicityorthogonaltofrequencyrepresentationinthecatauditorycortex
AT dinsehubertr mapofperiodicityorthogonaltofrequencyrepresentationinthecatauditorycortex
AT goddeben mapofperiodicityorthogonaltofrequencyrepresentationinthecatauditorycortex