Open AccessStrong rightward lateralization of the dorsal attentional network in left‐handers with right sighting‐eye: An evolutionary advantage
Author(s) -
Petit Laurent,
Zago Laure,
Mellet Emmanuel,
Jobard Gaël,
Crivello Fabrice,
Joliot Marc,
Mazoyer Bernard,
TzourioMazoyer Nathalie
Publication year - 2015
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.22693
Subject(s) - lateralization of brain function , psychology , context (archaeology) , ocular dominance , laterality , neuroscience , saccadic masking , perception , functional magnetic resonance imaging , eye movement , spatial contextual awareness , attention network , population , cognitive psychology , visual cortex , medicine , computer science , artificial intelligence , paleontology , environmental health , biology
Hemispheric lateralization for spatial attention and its relationships with manual preference strength and eye preference were studied in a sample of 293 healthy individuals balanced for manual preference. Functional magnetic resonance imaging was used to map this large sample while performing visually guided saccadic eye movements. This activated a bilateral distributed cortico‐subcortical network in which dorsal and ventral attentional/saccadic pathways elicited rightward asymmetrical activation depending on manual preference strength and sighting eye. While the ventral pathway showed a strong rightward asymmetry irrespective of both manual preference strength and eye preference, the dorsal frontoparietal network showed a robust rightward asymmetry in strongly left‐handers, even more pronounced in left‐handed subjects with a right sighting‐eye. Our findings brings support to the hypothesis that the origin of the rightward hemispheric dominance for spatial attention may have a manipulo‐spatial origin neither perceptual nor motor per se but rather reflecting a mechanism by which a spatial context is mapped onto the perceptual and motor activities, including the exploration of the spatial environment with eyes and hands. Within this context, strongly left‐handers with a right sighting‐eye may benefit from the advantage of having the same right hemispheric control of their dominant hand and visuospatial attention processing. We suggest that this phenomenon explains why left‐handed right sighting‐eye athletes can outperform their competitors in sporting duels and that the prehistoric and historical constancy of the left‐handers ratio over the general population may relate in part on the hemispheric specialization of spatial attention. Hum Brain Mapp 36:1151–1164, 2015. © 2014 Wiley Periodicals, Inc.