Document Detail


Spatial tuning to sound source azimuth in the inferior colliculus of the unanesthetized rabbit.
MedLine Citation:
PMID:  21849611     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Despite decades of research devoted to the study of inferior colliculus (IC) neurons' tuning to sound-source azimuth, there remain many unanswered questions because no previous study examined azimuth tuning over a full range of 360° azimuths at a wide range of stimulus levels in an unanesthetized preparation. Furthermore, a comparison of azimuth tuning to binaural and contralateral-ear stimulation over ranges of full azimuths and widely varying stimulus levels was not previously reported. To fill this void, we conducted a study of azimuth tuning in the IC of the unanesthetized rabbit over a 300° range of azimuths at stimulus levels of 10-50 dB re: neural threshold to both binaural and contralateral-ear stimulation using virtual auditory space VAS stimuli. This study provides systematic evidence for neural coding of azimuth. We found the following: 1. Level tolerant azimuth tuning was observed in top 35% regarding vector strength and in the top 15% regarding vector angle of IC neurons. 2. Preserved azimuth tuning to binaural stimulation at high stimulus levels was created as a consequence of binaural facilitation in the contralateral sound field and binaural suppression in the ipsilateral sound field. 3. The direction of azimuth tuning to binaural stimulation was primarily in the contralateral sound field and its center shifted laterally towards -90° with increasing stimulus level. 4. At 10 dB, azimuth tuning to binaural and contralateral stimulation was similar indicating that it was mediated by monaural mechanisms. 5. At higher stimulus levels azimuth tuning to contralateral-ear stimulation was severely degraded. These findings form a foundation for understanding neural mechanisms of localizing sound-source azimuth.
Authors:
Shigeyuki Kuwada; Brian Benjamin Bishop; Caitlin Alex; Daniel William Condit; Duck O Kim
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-8-17
Journal Detail:
Title:  Journal of neurophysiology     Volume:  -     ISSN:  1522-1598     ISO Abbreviation:  -     Publication Date:  2011 Aug 
Date Detail:
Created Date:  2011-8-19     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0375404     Medline TA:  J Neurophysiol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
1University of Connecticut Health Center.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

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


Previous Document:  Gain-specific and probability-independent reward skewness coding in the insula.
Next Document:  Neural correlates of evidence accumulation in a perceptual decision task.