title: Cortical Thickness and Local Gyrification in Children with Developmental Dyslexia.
abstract: Developmental dyslexia is frequently associated with atypical brain structure and function within regions of the left hemisphere reading network. To date, few studies have employed surface-based techniques to evaluate cortical thickness and local gyrification in dyslexia. Of the existing cortical thickness studies in children, many are limited by small sample size, variability in dyslexia identification, and the recruitment of prereaders who may or may not develop reading impairment. Further, no known study has assessed local gyrification index (LGI) in dyslexia, which may serve as a sensitive indicator of atypical neurodevelopment. In this study, children with dyslexia (n = 31) and typically decoding peers (n = 45) underwent structural magnetic resonance imaging to assess whole-brain vertex-wise cortical thickness and LGI. Children with dyslexia demonstrated reduced cortical thickness compared with controls within previously identified reading areas including bilateral occipitotemporal and occipitoparietal regions. Compared with controls, children with dyslexia also showed increased gyrification in left occipitotemporal and right superior frontal cortices. The convergence of thinner and more gyrified cortex within the left occipitotemporal region among children with dyslexia may reflect its early temporal role in processing word forms, and highlights the importance of the ventral stream for successful word reading.
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204, USA.
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Williams
authors.affiliation: Department of Pediatrics, University of Texas Health Science Center, Houston, TX 77030, USA.
authors.forename: Jenifer
authors.initials: J
authors.lastname: Juranek
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204, USA.|Department of Psychology and Texas Institute for Measurement, Evaluation, and Statistics (TIMES), University of Houston, Houston, TX 77204, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Cirino
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204, USA.|Department of Psychology and Texas Institute for Measurement, Evaluation, and Statistics (TIMES), University of Houston, Houston, TX 77204, USA.
authors.forename: Jack M
authors.initials: JM
authors.lastname: Fletcher
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D004410:Dyslexia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007360:Intelligence; D008279:Magnetic Resonance Imaging; D008297:Male; D011932:Reading
keywords: cortex; decoding; neurodevelopment; reading disability