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Titolo:
The auditory 'C-process': analyzing the spectral envelope of complex sounds
Autore:
Jones, SJ; Perez, N;
Indirizzi:
Natl Hosp Neurol & Neurosurg, London WC1N 3BG, England Natl Hosp Neurol & Neurosurg London England WC1N 3BG n WC1N 3BG, England
Titolo Testata:
CLINICAL NEUROPHYSIOLOGY
fascicolo: 6, volume: 112, anno: 2001,
pagine: 965 - 975
SICI:
1388-2457(200106)112:6<965:TA'ATS>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
ENG
Soggetto:
TONOTOPIC ORGANIZATION; EVOKED-POTENTIALS; MULTIFREQUENCY SOUNDS; AMPLITUDE-MODULATION; POPULATION RESPONSES; CORTEX NEURONS; CAT; TONES; REPRESENTATION; PITCH;
Keywords:
auditory cortex; auditory evoked potential; complex tones; spectral envelope analysis; timbre;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
42
Recensione:
Indirizzi per estratti:
Indirizzo: Jones, SJ Natl Hosp Neurol & Neurosurg, Queen Sq, London WC1N 3BG, EnglandNatl Hosp Neurol & Neurosurg Queen Sq London England WC1N 3BG d
Citazione:
S.J. Jones e N. Perez, "The auditory 'C-process': analyzing the spectral envelope of complex sounds", CLIN NEU, 112(6), 2001, pp. 965-975

Abstract

Objective: To examine the hypothesis that auditory evoked potentials (AEPs) to pitch and timbre change of complex harmonic tones reflect a process ofspectral envelope analysis. Methods: AEPs were recorded to: (1)continuous tones of 'clarinet' timbre whose pitch abruptly rose or fell by 1 or 7 semitones every 0.5 or 1.5 s; (2) a cycle of 6 pitches changing every 0.5 s; (3) tones of constant pitch whose timbre (spectral envelope shape) changed periodically: (4) pitch changeof high- acid low-pass filtered 'clarinet' tones. Results: The amplitudes of the 'change-N 1 (CN1) potential peaking at ca. 90 ms and the following CP2 were influenced to a far greater degree by the time interval between changes, than by the magnitude of the change or by the time interval between occurrences of the same pitch. Amplitudes were alsostrongly dependent on the number of partials present, irrespective of whether they were increasing or decreasing in energy. The algebraic sum of the responses to pitch change of high- and low-pass filtered tones closely approximated the response to the unfiltered tone. Conclusion: The rate-sensitivity of the responses cannot be explained by the refractoriness of Frequency-specific 'feature detector neurones, but rather of a process (termed 'C-process') which analyzes amplitude modulations across the spectral envelope, the contribution of different frequency bandscombining linearly in the scalp-recorded activity. On-going computation ofthe spectral envelope shape may be an important factor in maintaining the perceptual constancy of timbre. (C) 2001 Elsevier science Ireland Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/01/20 alle ore 20:34:30