| Gap encoding by inferior collicular neurons is altered by minimal changes in signal envelope. | |
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MedLine Citation:
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PMID: 9472732 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Neural correlates of temporal resolution in the central auditory system are currently under intense investigation. The gap detection paradigm offers a simple, yet important, test of temporal acuity because changes in behavioral gap thresholds have been correlated with deficits in complex stimulus processing, such as speech perception. In gap detection studies, silent gaps are typically shaped by rapid (< 1.0 ms) rise/fall (R/F) times, i.e., rapid decreases and increases in sound intensity. However, in nature, the envelopes surrounding silent periods can vary significantly in R/F time. Therefore, we investigated whether changes in the R/F time surrounding the silent gap affect neural processing by inferior collicular (IC) neurons. Gap R/F times were varied between 0.5 and 16 ms and the discharge pattern, response rate, and first spike latency of IC neurons were measured for gap widths up to 100 ms. Neurons were classified into phasic or tonic discharge patterns based on peri-stimulus time histograms elicited to 100 ms noise carriers. The results indicate that (1) minimal gap thresholds increased with R/F time regardless of response type, (2) first spike latency variance increased systematically with R/F time for units which had small first spike standard deviations at short R/F times, and (3) the response rate of some units (called 'gap-tuned') changed as a function of both R/F time and gap width. Gap-tuned units responded strongly to a particular gap width only when the envelope of the gap was shaped by a particular R/F time. For gap-tuned units, increases in R/F time shifted the tuning to larger gap widths and also broadened the response profile. These results show that temporal acuity of neurons in the IC, as measured by the gap detection paradigm, is sensitive to the envelope surrounding gaps embedded in noise carriers. |
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Authors:
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K Barsz; P K Benson; J P Walton |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Hearing research Volume: 115 ISSN: 0378-5955 ISO Abbreviation: Hear. Res. Publication Date: 1998 Jan |
Date Detail:
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Created Date: 1998-04-07 Completed Date: 1998-04-07 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 7900445 Medline TA: Hear Res Country: NETHERLANDS |
Other Details:
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Languages: eng Pagination: 13-26 Citation Subset: IM |
Affiliation:
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Department of Surgery, University of Rochester School of Medicine and Dentistry, NY 14642-8629, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Acoustic Stimulation Animals Auditory Perception / physiology* Auditory Threshold / physiology* Inferior Colliculi / cytology, physiology* Mice Mice, Inbred Strains Neurons / physiology Noise* Signal Transduction Time Factors |
| Grant Support | |
ID/Acronym/Agency:
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P01 AG09524/AG/NIA NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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