Learning-induced plasticity in auditory spatial representations revealed by electrical neuroimaging.

Détails

Ressource 1Télécharger: 5474.full.pdf (513.43 [Ko])
Etat: Serval
Version: Final published version
ID Serval
serval:BIB_95AB8429A28F
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Learning-induced plasticity in auditory spatial representations revealed by electrical neuroimaging.
Périodique
Journal of Neuroscience
Auteur(s)
Spierer L., Tardif E., Sperdin H., Murray M.M., Clarke S.
ISSN
1529-2401[electronic]
Statut éditorial
Publié
Date de publication
2007
Volume
27
Numéro
20
Pages
5474-5483
Langue
anglais
Résumé
Auditory spatial representations are likely encoded at a population level within human auditory cortices. We investigated learning-induced plasticity of spatial discrimination in healthy subjects using auditory-evoked potentials (AEPs) and electrical neuroimaging analyses. Stimuli were 100 ms white-noise bursts lateralized with varying interaural time differences. In three experiments, plasticity was induced with 40 min of discrimination training. During training, accuracy significantly improved from near-chance levels to approximately 75%. Before and after training, AEPs were recorded to stimuli presented passively with a more medial sound lateralization outnumbering a more lateral one (7:1). In experiment 1, the same lateralizations were used for training and AEP sessions. Significant AEP modulations to the different lateralizations were evident only after training, indicative of a learning-induced mismatch negativity (MMN). More precisely, this MMN at 195-250 ms after stimulus onset followed from differences in the AEP topography to each stimulus position, indicative of changes in the underlying brain network. In experiment 2, mirror-symmetric locations were used for training and AEP sessions; no training-related AEP modulations or MMN were observed. In experiment 3, the discrimination of trained plus equidistant untrained separations was tested psychophysically before and 0, 6, 24, and 48 h after training. Learning-induced plasticity lasted <6 h, did not generalize to untrained lateralizations, and was not the simple result of strengthening the representation of the trained lateralizations. Thus, learning-induced plasticity of auditory spatial discrimination relies on spatial comparisons, rather than a spatial anchor or a general comparator. Furthermore, cortical auditory representations of space are dynamic and subject to rapid reorganization.
Mots-clé
Acoustic Stimulation, Adult, Auditory Cortex, Electroencephalography, Evoked Potentials, Auditory, Female, Humans, Learning, Male, Neuronal Plasticity, Psychomotor Performance, Reaction Time
Pubmed
Web of science
Open Access
Oui
Création de la notice
25/01/2008 12:34
Dernière modification de la notice
08/05/2019 22:17
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