The association between hemispheric specialization for language production and for spatial attention depends on left-hand preference strength.

Laure Zago, Laurent Petit, Emmanuel Mellet, Gaël Jobard, Fabrice Crivello, Marc Joliot, Bernard Mazoyer, Nathalie Tzourio-Mazoyer
Neuropsychologia. 2016-12-01; 93: 394-406
DOI: 10.1016/j.neuropsychologia.2015.11.018

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1. Neuropsychologia. 2016 Dec;93(Pt B):394-406. doi:
10.1016/j.neuropsychologia.2015.11.018. Epub 2015 Nov 25.

The association between hemispheric specialization for language production and
for spatial attention depends on left-hand preference strength.

Zago L(1), Petit L(2), Mellet E(2), Jobard G(2), Crivello F(2), Joliot M(2),
Mazoyer B(2), Tzourio-Mazoyer N(2).

Author information:
(1)CNRS, UMR 5296, Groupe d’Imagerie Neurofonctionnelle, Bordeaux, France; CEA,
UMR 5296, Groupe d’Imagerie Neurofonctionnelle, Bordeaux, France; Université de
Bordeaux, UMR 5296, Groupe d’Imagerie Neurofonctionnelle, Bordeaux, France.
Electronic address: .
(2)CNRS, UMR 5296, Groupe d’Imagerie Neurofonctionnelle, Bordeaux, France; CEA,
UMR 5296, Groupe d’Imagerie Neurofonctionnelle, Bordeaux, France; Université de
Bordeaux, UMR 5296, Groupe d’Imagerie Neurofonctionnelle, Bordeaux, France.

Cerebral lateralization for language production and spatial attention and their
relationships with manual preference strength (MPS) were assessed in a sample of
293 healthy volunteers, including 151 left-handers, using fMRI during covert
sentence production (PROD) and line bisection judgment (LBJ) tasks, as compared
to high- and low-level reference tasks. At the group level, we found the expected
complementary hemispheric specialization (HS) with leftward asymmetries for PROD
within frontal and temporal regions and rightward asymmetries for LBJ within
frontal and posterior occipito-parieto-temporal regions. Individual hemispheric
(HLI) and regional (frontal and occipital) lateralization indices (LI) were then
calculated on the activation maps for PROD and LBJ. We found a correlation
between the degree of rightward cerebral asymmetry and the leftward behavioral
attentional bias recorded during LBJ task. This correlation was found when LBJ-LI
was computed over the hemispheres, in the frontal lobes, but not in the occipital
lobes. We then investigated whether language production and spatial attention
cerebral lateralization relate to each other, and whether manual preference was a
variable that impacted the complementary HS of these functions. No correlation
was found between spatial and language LIs in the majority of our sample of
participants, including right-handers with a strong right-hand preference (sRH,
n=97) and mixed-handers (MH, n=97), indicating that these functions lateralized
independently. By contrast, in the group of left-handers with a strong left-hand
preference (sLH, n= 99), a negative correlation was found between language and
spatial lateralization. This negative correlation was found when LBJ-LI and
PROD-LI were computed over the hemispheres, in the frontal lobes and between the
occipital lobes for LBJ and the frontal lobes for PROD. These findings underline
the importance to include sLH in the study sample to reveal the underlying
mechanisms of complementary HS.

Copyright © 2015 Elsevier Ltd. All rights reserved.

DOI: 10.1016/j.neuropsychologia.2015.11.018
PMID: 26626612 [Indexed for MEDLINE]


Auteurs Bordeaux Neurocampus