Development of handedness, anatomical and functional brain lateralization
Handbook of Clinical Neurology. 2020-01-01; : 99-105
DOI: 10.1016/b978-0-444-64150-2.00011-3
Lire sur PubMed
Tzourio-Mazoyer N(1), Zago L(2), Cochet H(3), Crivello F(2).
Author information:
(1)Institut des Maladies Neurodegeneratives, University of Bordeaux, Bordeaux, France. Electronic address: .
(2)Institut des Maladies Neurodegeneratives, University of Bordeaux, Bordeaux, France.
(3)Laboratoire Cognition, Langues, Langage, et Ergonomie, Toulouse University, CNRS, UT2J, Toulouse, France.
The present chapter offers a report on the recent literature on the neural bases
of hemispheric specialization (HS), anatomical and functional developmental
timecourse of HS, and on the available knowledge of their relationships with the
development of handedness. Strong anatomical asymmetries can be seen located
along the end of the sylvian fissure and the superior temporal sulcus (STS) as
soon as the 23rd gestational week. They correspond to a leftward sulcal depth
asymmetry of the Sylvian fissure coupled with a rightward asymmetry of STS. These
neonatal asymmetries targeting speech processing areas do not further change with
development. Different from these anatomical asymmetries, the functional
asymmetries of language areas develop during childhood. Such a development is
characterized at birth by a predominant interhemispheric intrinsic connectivity
between homotopic areas that will evolve toward left hemisphere intrahemispheric
intrinsic connectivity between anterior and posterior language poles. The
development of such a typical architecture of language networks in the left
hemisphere dominant for language in more than 90% of humans translates into a
continuous increase in the leftward asymmetries of activation during language
production throughout childhood. With regard to the rightward cerebral
lateralization for visuospatial functions, neuroimaging studies tend to indicate
an increase in rightward lateralization of frontal-parietal network with age
during visuospatial memory and visuospatial search tasks. In addition, the
spatial-attentional behavioral asymmetries emerge early (in preschool children)
and, then, can be modulated by factors linked to motor asymmetry and handedness.
Finally, the study of manual lateralization in relation to language development
has shown the importance of considering several characteristics of manual
activities. In particular, the dissociation between manipulative activities and
communicative gestures in young children may open further perspectives for future
research on HS.