Weak language lateralization affects both verbal and spatial skills: An fMRI study in 297 subjects

E Mellet, L Zago, G Jobard, F Crivello, L Petit, M Joliot, B Mazoyer, N Tzourio-Mazoyer
Neuropsychologia. 2014-12-01; 65: 56-62
DOI: 10.1016/j.neuropsychologia.2014.10.010

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1. Neuropsychologia. 2014 Dec;65:56-62. doi: 10.1016/j.neuropsychologia.2014.10.010.
Epub 2014 Oct 22.

Weak language lateralization affects both verbal and spatial skills: an fMRI
study in 297 subjects.

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

Author information:
(1)Université de Bordeaux, GIN, UMR 5296, F-33000 Bordeaux, France; CNRS, GIN,
UMR 5296, F-33000 Bordeaux, France; CEA, GIN, UMR 5296, F-33000 Bordeaux, France.
Electronic address: .
(2)Université de Bordeaux, GIN, UMR 5296, F-33000 Bordeaux, France; CNRS, GIN,
UMR 5296, F-33000 Bordeaux, France; CEA, GIN, UMR 5296, F-33000 Bordeaux, France.

The present study reappraised the relationship between hemispheric specialization
strength and cognitive skills in a sample of 297 individuals including 153
left-handers. It additionally assessed the interaction with manual laterality
factors, such as handedness, asymmetry of hand motor skills, and familial
sinistrality. A Hemispheric Functional Lateralization Index (HFLI) for language
was derived from fMRI. Through mixture Gaussian modeling, three types of language
hemispheric lateralization were defined: typical (left hemisphere dominance with
clear positive HFLI), ambilateral (no dominant hemisphere with HFLI values close
to 0), and strongly-atypical (right-hemisphere dominance with clear negative HFLI
values). Three cognitive scores were derived from 12 tests covering various
aspects of verbal and spatial cognition. Compared to both typical and
strongly-atypical participants, those ambilateral for language production had
lower performances in verbal and non-verbal domains, indicating that hemispheric
specialization and cognitive skills are related in adults. Furthermore, this
relationship was independent from handedness and asymmetry for motor skills, as
no interaction was observed between these factors. On the other hand, the
relationship between familial sinistrality and cognitive skills tended to differ
according to language lateralization type. In contrast to previous reports in
children, in the present adult population, we found no linear correlation between
HFLI and cognitive skills, regardless of lateralization type.

Copyright © 2014 Elsevier Ltd. All rights reserved.

DOI: 10.1016/j.neuropsychologia.2014.10.010
PMID: 25455569 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus