Left hemisphere lateralization for language in right-handers is controlled in part by familial sinistrality, manual preference strength, and head size
Journal of Neuroscience. 2010-10-06; 30(40): 13314-13318
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1. J Neurosci. 2010 Oct 6;30(40):13314-8. doi: 10.1523/JNEUROSCI.2593-10.2010.
Left hemisphere lateralization for language in right-handers is controlled in
part by familial sinistrality, manual preference strength, and head size.
Tzourio-Mazoyer N(1), Petit L, Razafimandimby A, Crivello F, Zago L, Jobard G,
Joliot M, Mellet E, Mazoyer B.
(1)Groupe d’Imagerie Neurofonctionnelle, Unité Mixte de Recherche 6232, Centre
National de la Recherche Scientifique France, Commissariat à l’Energie Atomique,
We investigated the effects of familial sinistrality (FS+; presence of
left-handedness in one’s close relatives), manual preference strength (MPS), and
head size on the hemispheric lateralization of language in right-handers.
Functional magnetic resonance imaging was used to map 49 individuals while
listening to a story in their mother tongue. We found that individuals who had
both the FS+ trait and weak MPS had no left hemisphere dominance for this
lexicosyntactic task, whereas others showed a leftward functional asymmetry. In
addition, the smaller the brain size, the smaller the leftward asymmetry for
language, independent of FS and MPS. None of these effects were observed when the
same subjects performed a spatial attention task that elicited right hemispheric
functional asymmetry. These results demonstrate that the left hemisphere
dominance for language in right-handers is a variable controlled, in part, by a
number of specific factors, including FS, MPS, and head size.
PMID: 20926657 [Indexed for MEDLINE]