title: Myelination Is Associated with Processing Speed in Early Childhood: Preliminary Insights.
abstract: Processing speed is an important contributor to working memory performance and fluid intelligence in young children. Myelinated white matter plays a central role in brain messaging, and likely mediates processing speed, but little is known about the relationship between myelination and processing speed in young children. In the present study, processing speed was measured through inspection times, and myelin volume fraction (VFM) was quantified using a multicomponent magnetic resonance imaging (MRI) approach in 2- to 5-years of age. Both inspection times and VFM were found to increase with age. Greater VFM in the right and left occipital lobes, the body of the corpus callosum, and the right cerebellum was significantly associated with shorter inspection times, after controlling for age. A hierarchical regression showed that VFM in the left occipital lobe predicted inspection times over and beyond the effects of age and the VFM in the other brain regions. These findings are consistent with the hypothesis that myelin supports processing speed in early childhood.
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chevalier
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, United States of America.
authors.forename: Salome
authors.initials: S
authors.lastname: Kurth
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, United States of America.
authors.forename: Margaret Rae
authors.initials: MR
authors.lastname: Doucette
authors.affiliation: Department of Psychology, York University, Toronto, Ontario, Canada.
authors.forename: Melody
authors.initials: M
authors.lastname: Wiseheart
authors.affiliation: Brown University School of Engineering, Providence, Rhodes Island, United States of America.
authors.forename: Sean C L
authors.initials: SC
authors.lastname: Deoni
authors.affiliation: Brown University School of Engineering, Providence, Rhodes Island, United States of America.
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Dean
authors.affiliation: Department of Neuroimaging, King's College London, Institute of Psychiatry, London, United Kingdom.
authors.forename: Jonathan
authors.initials: J
authors.lastname: O'Muircheartaigh
authors.affiliation: Department of Psychology, Salem College, Winston-Salem, North Carolina, United States of America.
authors.forename: Katharine A
authors.initials: KA
authors.lastname: Blackwell
authors.affiliation: Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Munakata
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, United States of America.
authors.forename: Monique K
authors.initials: MK
authors.lastname: LeBourgeois
mesh_terms: D001921:Brain / Q000033:anatomy & histology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009186:Myelin Sheath; D009483:Neuropsychological Tests; D011340:Problem Solving / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D066127:White Matter / Q000033:anatomy & histology*