The relative detectability for mice of gaps having different ramp durations at their onset and offset boundaries
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- James R. Ison
- Department of Brain and Cognitive Sciences and Division of Otolaryngology, Department of Surgery, University of Rochester, Rochester, New York 14627
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- Jason Castro
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, New York 14627
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- Paul Allen
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, New York 14627
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- Tracy M. Virag
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, New York 14627
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- Joseph P. Walton
- Division of Otolaryngology, Department of Surgery, University of Rochester, Rochester, New York 14627
説明
<jats:p>The effect on gap detectability of varying noise fall time (FT) and rise time (RT) of the gap boundary ramps was examined in mice using reflex modification audiometry, measuring inhibition of acoustic startle reflexes by variously shaped gaps just preceding reflex expression. In experiment 1 (n=12) inhibition increased up to near-asymptotic values with longer FT (0, 1, 2, 3, 5, or 10 ms) and QT (quiet time, 0 to 13 ms), with a 2:1 trade-off between FT and QT. In experiment 2 (n=24) inhibition increased for any RT above 0 ms (2, 3, 5, or 7 ms) if QT=1 ms, but diminished with increased RT when QT=3 or 8 ms. Enhanced detectability for subthreshold gaps by longer ramps results from their extending the apparent gap duration. The negative effect of increased RT for threshold gaps suggests the importance for gap detection of the stronger neural responses to sharp edges at the end of the gap shown previously in the mouse inferior colliculus. These effects are specific to gaps: inhibition for fixed (70-dB SPL) or varied level pulses (30 to 60 dB) was unaffected by varying the ramped edges (experiments 3 and 4, n=9).</jats:p>
収録刊行物
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- The Journal of the Acoustical Society of America
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The Journal of the Acoustical Society of America 112 (2), 740-747, 2002-07-31
Acoustical Society of America (ASA)