Putative protective neural mechanisms in prereaders with a family history of dyslexia who subsequently develop typical reading skills

May 13, 2020 | New Research

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Xi Yu1,2 | Jennifer Zuk2 | Meaghan V. Perdue2,3,4 | Ola Ozernov-Palchik2,5 |
Talia Raney2 | Sara D. Beach5,6 | Elizabeth S. Norton7 | Yangming Ou8,9,10 |
John D. E. Gabrieli5 | Nadine Gaab2,11,12

  1. State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
  2. Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts
  3. Department of Psychological Sciences, University of Connecticut, Storrs, Connecticut
  4. Haskins Laboratories, New Haven, Connecticut
  5. McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
  6. Division of Medical Sciences, Harvard University, Cambridge, Massachusetts
  7. Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois
  8. Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts
  9. Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, Massachusetts
  10. Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts
  11. Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
  12. Harvard Graduate School of Education, Cambridge, Massachusetts

Abstract
Developmental dyslexia affects 40–60% of children with a familial risk (FHD+) compared to a general prevalence of 5–10%. Despite the increased risk, about half of FHD+ children develop typical reading abilities (FHD+Typical). Yet the underlying neural characteristics of favorable reading outcomes in at-risk children remain unknown. Utilizing a retrospective, longitudinal approach, this study examined whether putative protective neural mechanisms can be observed in FHD+Typical at the prereading stage. Functional and structural brain characteristics were examined in 47 FHD+ prereaders who subsequently developed typical (n = 35) or impaired (n = 12) reading abilities and 34 controls (FHD−Typical). Searchlight-based multivariate pattern analyses identified distinct activation patterns during phonological processing between FHD+Typical and FHD−Typical in right inferior frontal gyrus (RIFG) and left temporo-parietal cortex (LTPC) regions. Follow-up analyses on groupspecific classification patterns demonstrated LTPC hypoactivation in FHD+Typical compared to FHD−Typical, suggesting this neural characteristic as an FHD+ phenotype. In contrast, RIFG showed hyperactivation in FHD+Typical than FHD−Typical, and its activation pattern was positively correlated with subsequent reading abilities in FHD+ but not controls (FHD−Typical). RIFG hyperactivation in FHD+Typical was further associated with increased interhemispheric functional and structural connectivity. These results suggest that some protective neural mechanisms are already established in FHD+Typical prereaders supporting their typical reading development.

KEYWORDS
children, developmental dyslexia, DTI, functional MRI, pediatric neuroimaging