Exploring the early organization and maturation of linguistic pathways in the human infant brain

Jessica Dubois (1) , Cyril Poupon (2) , Bertrand Thirion (3) , Hina Simonnet (1) , Sofya Kulikova (4, 5) , François Leroy (1) , Lucie Hertz-Pannier (4, 5) , Ghislaine Dehaene-Lambertz (1)

1 UNICOG-U992 - Neuroimagerie cognitive - Psychologie cognitive expérimentale
2 UNIRS - Unité d'imagerie par résonance magnétique à très haut champ et de spectroscopie
3 PARIETAL - Modelling brain structure, function and variability based on high-field MRI data
4 UNIACT - Unité de recherche en NeuroImagerie Applicative Clinique et Translationnelle
5 U1129 - Epilepsies de l'Enfant et Plasticité Cérébrale

Linguistic processing is based on a close collaboration between temporal and frontal regions connected by two pathways: the "dorsal" and "ventral pathways" (assumed to support phonological and semantic processing respectively in adults). We investigated here the development of these pathways at the onset of language acquisition, during the first post-natal weeks, using cross-sectional diffusion imaging in 21 healthy infants (6 to 22 weeks of age) and 17 young adults. We compared the bundle organization and microstructure at these two ages using tractography and original clustering analyses of DTI parameters. We observed structural similarities between both groups, especially concerning the dorsal/ventral pathway segregation and the arcuate fasciculus asymmetry. We further highlighted the developmental tempos of the linguistic bundles: the ventral pathway maturation was more advanced than the dorsal pathway maturation, but the latter catches up during the first post-natal months. Its fast development during this period might relate to the learning of speech cross-modal representations and to the first combinatorial analyses of the speech input.

Mots clés: Inter-hemispheric asymmetry; Language network; Diffusion imaging; Brain development; White matter maturation and myelination

Domaines: Sciences du Vivant [q-bio]; Neurosciences [q-bio.NC]

Jessica Dubois, Cyril Poupon, Bertrand Thirion, Hina Simonnet, Sofya Kulikova, et al.. Exploring the early organization and maturation of linguistic pathways in the human infant brain. Cerebral Cortex, 2016, 26 (5), pp.2283-2298. ⟨10.1093/cercor/bhv082⟩. ⟨hal-02436257⟩