HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 94/5/3523    most recent 01194.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Sinex, D. G. Articles by Velenovsky, D. S. Search for Related Content PubMed PubMed Citation Articles by Sinex, D. G. Articles by Velenovsky, D. S.

Prevalence of Stereotypical Responses to Mistuned Complex Tones in the Inferior Colliculus

¹Department of Speech and Hearing Science, Arizona State University, Tempe, Arizona; and ²Department of Psychology, Utah State University, Logan, Utah

Submitted 19 November 2004; accepted in final form 29 July 2005

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.

This article has been cited by other articles:

				H.-R. Geis and J. G. G. Borst Intracellular Responses of Neurons in the Mouse Inferior Colliculus to Sinusoidal Amplitude-Modulated Tones J Neurophysiol, April 1, 2009; 101(4): 2002 - 2016. [Abstract] [Full Text] [PDF]

				D. G. Sinex and H. Li Responses of Inferior Colliculus Neurons to Double Harmonic Tones J Neurophysiol, December 1, 2007; 98(6): 3171 - 3184. [Abstract] [Full Text] [PDF]

				M. L. Tan and J.G.G. Borst Comparison of Responses of Neurons in the Mouse Inferior Colliculus to Current Injections, Tones of Different Durations, and Sinusoidal Amplitude-Modulated Tones J Neurophysiol, July 1, 2007; 98(1): 454 - 466. [Abstract] [Full Text] [PDF]

				C. Alain and K. L. McDonald Age-Related Differences in Neuromagnetic Brain Activity Underlying Concurrent Sound Perception J. Neurosci., February 7, 2007; 27(6): 1308 - 1314. [Abstract] [Full Text] [PDF]