title: Unusual developmental pattern of brain lateralization in young boys with autism spectrum disorder: Power analysis with child-sized magnetoencephalography.
abstract: OBJECTIVE
  Autism spectrum disorder (ASD) is often described as comprising an unusual brain growth pattern and aberrant brain lateralization. Although it is important to study the pathophysiology of the developing ASD cortex, examples of physiological brain lateralization in young children with ASD have yet to be well examined.
  
  
  METHODS
  Thirty-eight boys with ASD (aged 3-7 years) and 38 typically developing (TD) boys (aged 3-8 years) concentrated on video programs and their brain activities were measured non-invasively. We employed a customized child-sized magnetoencephalography system in which the sensors were located as close to the brain as possible for optimal recording in young children. To produce a credible laterality index of the brain oscillations, we defined two clusters of sensors corresponding to the right and left hemispheres. We focused on the laterality index ([left - right]/[left+right]) of the relative power band in seven frequency bands.
  
  
  RESULTS
  The TD group displayed significantly rightward lateralized brain oscillations in the theta-1 frequency bands compared to the ASD group.
  
  
  CONCLUSIONS
  This is the first study to demonstrate unusual brain lateralization of brain oscillations measured by magnetoencephalography in young children with ASD.
authors.affiliation: Research Center for Child Mental Development, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Hiraishi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kitagawa
authors.forename: Chiaki
authors.initials: C
authors.lastname: Hasegawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Munesue
authors.forename: Natsumi
authors.initials: N
authors.lastname: Takesaki
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Ono
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Takahashi
authors.forename: Michio
authors.initials: M
authors.lastname: Suzuki
authors.forename: Haruhiro
authors.initials: H
authors.lastname: Higashida
authors.forename: Minoru
authors.initials: M
authors.lastname: Asada
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Minabe
mesh_terms: D000067877:Autism Spectrum Disorder / Q000503:physiopathology*; D001921:Brain / Q000254:growth & development* / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography; D008297:Male
keywords: autism; brain lateralization; magnetoencephalography; spontaneous brain activity; young children