Prevalence of stereotypical responses to mistuned complex tones in the inferior colliculus

Donal G. Sinex, Hongzhe Li, David S Velenovsky

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The human auditory system has an exceptional ability to separate competing sounds, but the neural mechanisms that underlie this ability are not understood. Responses of inferior colliculus (IC) neurons to "mistuned" complex tones were measured to investigate possible neural mechanisms for spectral segregation. A mistuned tone is a harmonic complex tone in which the frequency of one component has been changed; that component may be heard as a separate sound source, suggesting that the mistuned tone engages the same mechanisms that contribute to the segregation of natural sounds. In this study, the harmonic tone consisted of eight harmonics of 250 Hz; in the mistuned tone, the frequency of the fourth harmonic was increased by 12% (120 Hz). The mistuned tone elicited a stereotypical discharge pattern, consisting of peaks separated by about 8 ms and a response envelope modulated with a period of 100 ms, which bore little resemblance to the discharge pattern elicited by the harmonic tone or to the stimulus waveform. Similar discharge patterns were elicited from many neurons with a range of characteristic frequencies, especially from neurons that exhibited short-latency sustained responses to pure tones. In contrast, transient and long-latency neurons usually did not exhibit the stereotypical discharge pattern. The discharge pattern was generally stable when the stimulus level or component phase was varied; the major effect of these manipulations was to shift the phase of the response envelope. Simulation of IC responses with a computational model suggested that off-frequency inhibition could produce discharge patterns with these characteristics.

Original languageEnglish (US)
Pages (from-to)3523-3537
Number of pages15
JournalJournal of Neurophysiology
Volume94
Issue number5
DOIs
StatePublished - Nov 2005

Fingerprint

Inferior Colliculi
Neurons
Aptitude
Reaction Time

ASJC Scopus subject areas

  • Physiology
  • Neuroscience(all)

Cite this

Prevalence of stereotypical responses to mistuned complex tones in the inferior colliculus. / Sinex, Donal G.; Li, Hongzhe; Velenovsky, David S.

In: Journal of Neurophysiology, Vol. 94, No. 5, 11.2005, p. 3523-3537.

Research output: Contribution to journalArticle

@article{ecbcb1a7dc64453ebca09ff95478f6e0,
title = "Prevalence of stereotypical responses to mistuned complex tones in the inferior colliculus",
abstract = "The human auditory system has an exceptional ability to separate competing sounds, but the neural mechanisms that underlie this ability are not understood. Responses of inferior colliculus (IC) neurons to {"}mistuned{"} complex tones were measured to investigate possible neural mechanisms for spectral segregation. A mistuned tone is a harmonic complex tone in which the frequency of one component has been changed; that component may be heard as a separate sound source, suggesting that the mistuned tone engages the same mechanisms that contribute to the segregation of natural sounds. In this study, the harmonic tone consisted of eight harmonics of 250 Hz; in the mistuned tone, the frequency of the fourth harmonic was increased by 12{\%} (120 Hz). The mistuned tone elicited a stereotypical discharge pattern, consisting of peaks separated by about 8 ms and a response envelope modulated with a period of 100 ms, which bore little resemblance to the discharge pattern elicited by the harmonic tone or to the stimulus waveform. Similar discharge patterns were elicited from many neurons with a range of characteristic frequencies, especially from neurons that exhibited short-latency sustained responses to pure tones. In contrast, transient and long-latency neurons usually did not exhibit the stereotypical discharge pattern. The discharge pattern was generally stable when the stimulus level or component phase was varied; the major effect of these manipulations was to shift the phase of the response envelope. Simulation of IC responses with a computational model suggested that off-frequency inhibition could produce discharge patterns with these characteristics.",
author = "Sinex, {Donal G.} and Hongzhe Li and Velenovsky, {David S}",
year = "2005",
month = "11",
doi = "10.1152/jn.01194.2004",
language = "English (US)",
volume = "94",
pages = "3523--3537",
journal = "Journal of Neurophysiology",
issn = "0022-3077",
publisher = "American Physiological Society",
number = "5",

}

TY - JOUR

T1 - Prevalence of stereotypical responses to mistuned complex tones in the inferior colliculus

AU - Sinex, Donal G.

AU - Li, Hongzhe

AU - Velenovsky, David S

PY - 2005/11

Y1 - 2005/11

N2 - The human auditory system has an exceptional ability to separate competing sounds, but the neural mechanisms that underlie this ability are not understood. Responses of inferior colliculus (IC) neurons to "mistuned" complex tones were measured to investigate possible neural mechanisms for spectral segregation. A mistuned tone is a harmonic complex tone in which the frequency of one component has been changed; that component may be heard as a separate sound source, suggesting that the mistuned tone engages the same mechanisms that contribute to the segregation of natural sounds. In this study, the harmonic tone consisted of eight harmonics of 250 Hz; in the mistuned tone, the frequency of the fourth harmonic was increased by 12% (120 Hz). The mistuned tone elicited a stereotypical discharge pattern, consisting of peaks separated by about 8 ms and a response envelope modulated with a period of 100 ms, which bore little resemblance to the discharge pattern elicited by the harmonic tone or to the stimulus waveform. Similar discharge patterns were elicited from many neurons with a range of characteristic frequencies, especially from neurons that exhibited short-latency sustained responses to pure tones. In contrast, transient and long-latency neurons usually did not exhibit the stereotypical discharge pattern. The discharge pattern was generally stable when the stimulus level or component phase was varied; the major effect of these manipulations was to shift the phase of the response envelope. Simulation of IC responses with a computational model suggested that off-frequency inhibition could produce discharge patterns with these characteristics.

AB - The human auditory system has an exceptional ability to separate competing sounds, but the neural mechanisms that underlie this ability are not understood. Responses of inferior colliculus (IC) neurons to "mistuned" complex tones were measured to investigate possible neural mechanisms for spectral segregation. A mistuned tone is a harmonic complex tone in which the frequency of one component has been changed; that component may be heard as a separate sound source, suggesting that the mistuned tone engages the same mechanisms that contribute to the segregation of natural sounds. In this study, the harmonic tone consisted of eight harmonics of 250 Hz; in the mistuned tone, the frequency of the fourth harmonic was increased by 12% (120 Hz). The mistuned tone elicited a stereotypical discharge pattern, consisting of peaks separated by about 8 ms and a response envelope modulated with a period of 100 ms, which bore little resemblance to the discharge pattern elicited by the harmonic tone or to the stimulus waveform. Similar discharge patterns were elicited from many neurons with a range of characteristic frequencies, especially from neurons that exhibited short-latency sustained responses to pure tones. In contrast, transient and long-latency neurons usually did not exhibit the stereotypical discharge pattern. The discharge pattern was generally stable when the stimulus level or component phase was varied; the major effect of these manipulations was to shift the phase of the response envelope. Simulation of IC responses with a computational model suggested that off-frequency inhibition could produce discharge patterns with these characteristics.

UR - http://www.scopus.com/inward/record.url?scp=27144515535&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=27144515535&partnerID=8YFLogxK

U2 - 10.1152/jn.01194.2004

DO - 10.1152/jn.01194.2004

M3 - Article

VL - 94

SP - 3523

EP - 3537

JO - Journal of Neurophysiology

JF - Journal of Neurophysiology

SN - 0022-3077

IS - 5

ER -