Time-course of posterior parietal and occipital cortex contribution to sound localization in early blind and sighted subjects.
Poster Presentation

Olivier Collignon
Université de Montréal

Marco Davare
Université catholique de Louvain

Anne De Volder
Université catholique de Louvain

Claude Veraart
Université catholique de Louvain

Etienne Olivier
Université catholique de Louvain

Colline Poirier
University of Antwerp

Maryse Lassonde
Université de Montréal

Franco Lepore
Université de Montréal

     Abstract ID Number: 106
     Full text: Not available
     Last modified: May 30, 2007
     Presentation date: 07/07/2007 10:00 AM in Quad Maclauren Hall
     (View Schedule)

Abstract
We investigated the precise time-course of the contribution of the posterior parietal cortex (PPC) and the extrastriate occipital cortex (OC) to spatial processing of sounds in early blind (EB) and sighted subjects (SC) by using event-related Transcranial Magnetic Stimulation (TMS). Results indicate that a virtual lesion of the right PPC induced 100 and 150 ms after stimulus onset in SC led to a rightward bias for sounds presented on the left side, reproducing transiently the deficits commonly observed in hemineglect patients. In addition, we found that TMS applied over the right OC 50 ms after stimulus onset significantly impaired the localisation of sounds presented either on the right or on the left side in both populations. Our results extend our comprehension of the mechanisms underlying spatial hearing in EB and SC and point to extensive modifications of the network responsible for this ability in visually deprived subjects.