Regional and hemispheric determinants of language laterality: Implications for preoperative fMRI.

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Serval ID
serval:BIB_3D3E1D8999E8
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Regional and hemispheric determinants of language laterality: Implications for preoperative fMRI.
Journal
Human Brain Mapping
Author(s)
Seghier M.L., Kherif F., Josse G., Price C.J.
ISSN
1097-0193 (Electronic)
ISSN-L
1065-9471
Publication state
Published
Issued date
2011
Volume
32
Number
10
Pages
1602-1614
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
Language is typically a function of the left hemisphere but the right hemisphere is also essential in some healthy individuals and patients. This inter-subject variability necessitates the localization of language function, at the individual level, prior to neurosurgical intervention. Such assessments are typically made by comparing left and right hemisphere language function to determine "language lateralization" using clinical tests or fMRI. Here, we show that language function needs to be assessed at the region and hemisphere specific level, because laterality measures can be misleading. Using fMRI data from 82 healthy participants, we investigated the degree to which activation for a semantic word matching task was lateralized in 50 different brain regions and across the entire cortex. This revealed two novel findings. First, the degree to which language is lateralized across brain regions and between subjects was primarily driven by differences in right hemisphere activation rather than differences in left hemisphere activation. Second, we found that healthy subjects who have relatively high left lateralization in the angular gyrus also have relatively low left lateralization in the ventral precentral gyrus. These findings illustrate spatial heterogeneity in language lateralization that is lost when global laterality measures are considered. It is likely that the complex spatial variability we observed in healthy controls is more exaggerated in patients with brain damage. We therefore highlight the importance of investigating within hemisphere regional variations in fMRI activation, prior to neuro-surgical intervention, to determine how each hemisphere and each region contributes to language processing. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc.
Pubmed
Web of science
Open Access
Yes
Create date
14/03/2011 10:48
Last modification date
20/08/2019 13:33
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