La bosse des maths:
quand la langue change tout

Des chercheurs ont constaté que les anglophones et les sinophones ne mobilisaient pas les mêmes aires cérébrales pour effectuer des calculs. L'équipe de Yijun Liu, de l'Université de Floride, a comparé l'activité cérébrale de vingt-quatre étudiants de Dalian, dans le nord-est de la Chine. La moitié avait comme langue maternelle le chinois, et douze autres étaient anglophones (américains, anglais et australiens). Les étudiants ont été soumis à des tests de comparaison numérique rédigés en chiffres arabes. L'IRM a révélé que les anglophones faisaient davantage travailler les aires du cerveau dédiées au langage, tandis que les sinophones faisaient davantage appel à un réseau visuo-prémoteur des régions impliquées dans la visualisation et la spatialisation. Cette différence proviendrait de la façon dont les enfants apprennent leur langue maternelle. Le visuel a plus d'importance dans l'apprentissage du chinois, alors que les sons et l'intonation dominent pour l'anglais. Au-delà de la façon de voir les chiffres, on peut imaginer que c'est toute une façon de voir le monde qui diffère cérébralement selon les cultures occidentales ou orientales.

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Arithmetic processing in the brain shaped by cultures
Yiyuan Tang,,,, Wutian Zhang|, Kewei Chen,, Shigang Feng, Ye Ji, Junxian Shen, Eric M. Reiman, and Yijun Liu,
Institute of Neuroinformatics and Laboratory for Brain and Mind, Dalian University of Technology, Dalian 116023, China; State Key Laboratory for Brain and Cognitive Sciences and|Key Laboratory for Mental Health, Chinese Academy of Sciences, Beijing 100101, China; University of Florida McKnight Brain Institute, Gainesville, FL 32610; and Banner Alzheimer Institute and Banner PET Center, Banner Good Samaritan Medical Center, Phoenix, AZ 85006
Communicated by Michael I. Posner, University of Oregon, Eugene, OR, May 29, 2006 (received for review April 28, 2006)
The universal use of Arabic numbers in mathematics raises a question whether these digits are processed the same way in people speaking various languages, such as Chinese and English, which reflect differences in Eastern and Western cultures. Using functional MRI, we demonstrated a differential cortical representation of numbers between native Chinese and English speakers. Contrasting to native English speakers, who largely employ a language process that relies on the left perisylvian cortices for mental calculation such as a simple addition task, native Chinese speakers, instead, engage a visuo-premotor association network for the same task. Whereas in both groups the inferior parietal cortex was activated by a task for numerical quantity comparison, functional MRI connectivity analyses revealed a functional distinction between Chinese and English groups among the brain networks involved in the task. Our results further indicate that the different biological encoding of numbers may be shaped by visual reading experience during language acquisition and other cultural factors such as mathematics learning strategies and education systems, which cannot be explained completely by the differences in languages per se.
Arabic numbers | fMRI connectivity | premotor association area
Author contributions: Y.T., W.Z., and Y.L. designed research; Y.T., Y.J., and S.F. performed research; K.C. and Y.L. contributed new reagents/analytic tools; Y.T., K.C., S.F., E.M.R., Y.J., and Y.L. analyzed data; and Y.T., W.Z., K.C., J.S., E.M.R., and Y.L. wrote the paper.
Conflict of interest statement: No conflicts declared.
To whom correspondence may be addressed. E-mail: yy2100@163.net or yijunliu@ufl.edu
© 2006 by The National Academy of Sciences of the USA