Hemispheric competence for auditory spatial representation.

Détails

ID Serval
serval:BIB_094F78F02406
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Hemispheric competence for auditory spatial representation.
Périodique
Brain
Auteur(s)
Spierer L., Bellmann-Thiran A., Maeder P., Murray M.M., Clarke S.
ISSN
1460-2156[electronic]
Statut éditorial
Publié
Date de publication
2009
Volume
132
Numéro
Pt 7
Pages
1953-1966
Langue
anglais
Résumé
Sound localization relies on the analysis of interaural time and intensity differences, as well as attenuation patterns by the outer ear. We investigated the relative contributions of interaural time and intensity difference cues to sound localization by testing 60 healthy subjects: 25 with focal left and 25 with focal right hemispheric brain damage. Group and single-case behavioural analyses, as well as anatomo-clinical correlations, confirmed that deficits were more frequent and much more severe after right than left hemispheric lesions and for the processing of interaural time than intensity difference cues. For spatial processing based on interaural time difference cues, different error types were evident in the individual data. Deficits in discriminating between neighbouring positions occurred in both hemispaces after focal right hemispheric brain damage, but were restricted to the contralesional hemispace after focal left hemispheric brain damage. Alloacusis (perceptual shifts across the midline) occurred only after focal right hemispheric brain damage and was associated with minor or severe deficits in position discrimination. During spatial processing based on interaural intensity cues, deficits were less severe in the right hemispheric brain damage than left hemispheric brain damage group and no alloacusis occurred. These results, matched to anatomical data, suggest the existence of a binaural sound localization system predominantly based on interaural time difference cues and primarily supported by the right hemisphere. More generally, our data suggest that two distinct mechanisms contribute to: (i) the precise computation of spatial coordinates allowing spatial comparison within the contralateral hemispace for the left hemisphere and the whole space for the right hemisphere; and (ii) the building up of global auditory spatial representations in right temporo-parietal cortices.
Pubmed
Web of science
Création de la notice
22/06/2009 9:01
Dernière modification de la notice
03/03/2018 13:31
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