title: Altered hemispheric lateralization of white matter pathways in developmental dyslexia: Evidence from spherical deconvolution tractography.
abstract: This study examines the structural integrity and the hemispheric lateralization patterns of four major association fiber pathways in a group of French dyslexic children and age-matched controls (from 9 to 14 years), using high angular diffusion imaging combined with spherical deconvolution tractography. Compared with age-matched controls, dyslexic children show increased hindrance-modulated oriented anisotropy (HMOA) in the right superior longitudinal fasciculus (SLF). They also show a reduced leftward asymmetry of the inferior fronto-occipital fasciculus (IFOF) and an increased rightward asymmetry of the second branch of the SLF (SLF II). The lateralization pattern of IFOF and SLF II also accounts for individual differences in dyslexic children's reading abilities. These data provide evidence for an abnormal lateralization of occipito-frontal and parieto-frontal pathways in developmental dyslexia.
authors: School of Psychology, Shaanxi Normal University and Shaanxi Provincial Key Laboratory of Behavior and Cognitive Neuroscience, Xi'an, China; Laboratoire de Sciences Cognitives et Psycholinguistique (ENS, EHESS, CNRS), Département d'Etudes Cognitives, Ecole Normale Supérieure, PSL Research University, Paris Cedex 05, France. Electronic address: jingjing.zhao@snnu.edu.cn.
authors: Jingjing
authors: J
authors: Zhao
authors: Brain Connectivity and Behaviour Group, Brain and Spine Institute (ICM), CNRS UMR 7225, INSERM-UPMC UMRS 1127, Paris, France.
authors: Michel
authors: M
authors: Thiebaut de Schotten
authors: Laboratoire de Sciences Cognitives et Psycholinguistique (ENS, EHESS, CNRS), Département d'Etudes Cognitives, Ecole Normale Supérieure, PSL Research University, Paris Cedex 05, France; FPSE, University of Geneva, Geneva, Switzerland.
authors: Irene
authors: I
authors: Altarelli
authors: INSERM, U992, CEA/Neurospin, Gif-sur-Yvette, France; University Paris-Sud, Orsay, France.
authors: Jessica
authors: J
authors: Dubois
authors: Laboratoire de Sciences Cognitives et Psycholinguistique (ENS, EHESS, CNRS), Département d'Etudes Cognitives, Ecole Normale Supérieure, PSL Research University, Paris Cedex 05, France. Electronic address: franck.ramus@ens.fr.
authors: Franck
authors: F
authors: Ramus
mesh_terms: D000293:Adolescent; D001931:Brain Mapping / Q000379:methods; D002648:Child; D056324:Diffusion Tensor Imaging / Q000379:methods; D004410:Dyslexia / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007206:Individuality; D007802:Language; D008297:Male; D009434:Neural Pathways / Q000254:growth & development* / Q000503:physiopathology*; D066127:White Matter / Q000254:growth & development / Q000502:physiology*
keywords: Brain inter-hemispheric asymmetry; Developmental dyslexia; Diffusion imaging; Tractography; White matter