White Matter Maturation and Hemispheric Asymmetry During Childhood Based on Chinese Population

Influences of age and hemispheric asymmetry are important to white matter (WM) development, which are related with cognitive function development during childhood. However, the brainWMdevelopmental trajectory of Chinese children remains to be less fully investigated and possibly follows different trends compared with Western children, since there have been behavior or cognitive evidence suggesting the intercultural developmental differences between them. In this study, we utilized the cross-sectional diffusion tensor imaging technique to measure the age-related WM changes and hemispheric asymmetry in 71 right-handed Chinese children ranging in age from 6 to 10 years. DTI indices of fractional anisotropy (FA), mean diffusivity (MD), as well as axial diffusivity (AD) and radial diffusivity (RD) were assessed in 12 major white matter tracts in both two hemispheres respectively. We found the developmental age correlated positively with FA value and negatively with MD value in most WM regions observed. Besides, hemispheric asymmetry was identified in most of WM tracts. By contrast, the age-related WM changes and hemispheric asymmetry found in Chinese children population may be more widespread than in Western children population reported by previous studies. Overall, the present study characterized the influence of age and hemispheric asymmetry on WM of Chinese children's brain during development.