Sound localization in egocentric space following hemispheric lesions

Abstract

In this paper the performance of patients with unilateral hemispheric lesions ( n = 10 with right brain damage; n = 10 with left brain damage) on a free-field sound localization task was contrasted with that of healthy controls ( n = 10). Sound stimuli were presented binaurally in the horizontal plane from eight loudspeakers set at azimuths between −105° and +105°. Whereas performance of both patient groups was generally less accurate than controls, no evidence suggested that this was specific to the contralateral hemispace. The results indicate that both hemispheres play a role in sound localization, with systematic directional errors made towards the ipsilateral hemifield following unilateral lesions. Furthermore, particular location difficulties at pericentral positions (+15° and −15°) following right hemisphere damage, may indicate a specific function for the right hemisphere in determining personal frames of spatial reference within pericentral space.