Document Detail


Neuronal responses in cat inferior colliculus to combined acoustic and electric stimulation.
MedLine Citation:
PMID:  19955722     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The present study explored the interactions of combined electric and acoustic stimulation (EAS) on neural responses in the central auditory system. Normal-hearing cats were implanted unilaterally with scala tympani electrodes. Two experimental approaches were used. First, in a forward-masking paradigm, single biphasic electric pulses were used as maskers, unmodulated acoustic tone bursts at the neuron's characteristic frequency (CF) were used as probes. Then, in a simultaneous-masking paradigm, the masking effects of acoustic tones (CF) on responses to single electric pulses (probes) were examined. In the second approach, we studied the effects of phase relationship between acoustic and electric stimulation. Sinusoidal amplitude-modulated (30 Hz) CF tones and electric sinusoids (30 Hz) were shifted in relative phase (0-270 degrees). For all experimental conditions, the levels of the two stimuli were changed systematically. Responses were recorded in the contralateral central nucleus of the inferior colliculus. Single neuron analyses of spike rate and thresholds demonstrated that combined EAS resulted in complex interactions that were strongly dependent on the relative level of the given stimulus modes. The amount of masking increased with masker level and decreased with probe level. At higher current levels, the masking effect of electric responses dominated the effect of acoustic responses. The degree of these general masking effects was highly influenced by the relative phase between the combined stimuli. It seems likely that such interactions of combined stimulation have perceptual consequences in human cochlear implant subjects with residual hearing.
Authors:
Maike Vollmer; Rainer Hartmann; Jochen Tillein
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-11-25
Journal Detail:
Title:  Advances in oto-rhino-laryngology     Volume:  67     ISSN:  0065-3071     ISO Abbreviation:  Adv. Otorhinolaryngol.     Publication Date:  2010  
Date Detail:
Created Date:  2009-12-03     Completed Date:  2010-03-30     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0242534     Medline TA:  Adv Otorhinolaryngol     Country:  Switzerland    
Other Details:
Languages:  eng     Pagination:  61-9     Citation Subset:  IM    
Copyright Information:
Copyright 2010 S. Karger AG, Basel.
Affiliation:
Comprehensive Hearing Center, Department of Otolaryngology, Head and Neck Surgery, University Hospital W?rzburg, W?rzburg, Germany. vollmer_m@klinik.uni-wuerzburg.de
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MeSH Terms
Descriptor/Qualifier:
Acoustic Stimulation / methods*
Animals
Auditory Pathways / physiopathology*
Cats
Cochlear Implants*
Electric Stimulation / methods*
Hearing Loss / physiopathology*,  therapy
Inferior Colliculi / physiopathology*
Prognosis

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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