The brain basis of handwriting deficits in Chinese children with developmental dyslexia.
Yang Yang, Zhentao Zuo, Fred Tam, Simon J Graham, Junjun Li, Yuzhu Ji, Zelong Meng, Chanyuan Gu, Hong-Yan Bi, Jian Ou, Min Xu
Author Information
Yang Yang: CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology，Chinese Academy of Sciences, Beijing, China.
Zhentao Zuo: State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Fred Tam: Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada.
Simon J Graham: Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada.
Junjun Li: CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology，Chinese Academy of Sciences, Beijing, China.
Yuzhu Ji: Department of Psychology, College of Education, Zhejiang University of Technology, Hangzhou, China.
Zelong Meng: Department of Psychology, School of Humanities and Social Sciences, Beijing Forestry University, Beijing, China.
Chanyuan Gu: Department of Chinese and Bilingual Studies, Faculty of Humanities, The Hong Kong Polytechnic University, Hong Kong, China.
Hong-Yan Bi: CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology，Chinese Academy of Sciences, Beijing, China.
Jian Ou: Center for Brain Disorders and Cognitive Sciences, Shenzhen University, Shenzhen, China.
Min Xu: Center for Brain Disorders and Cognitive Sciences, Shenzhen University, Shenzhen, China. ORCID
Abundant behavioral studies have demonstrated high comorbidity of reading and handwriting difficulties in developmental dyslexia (DD), a neurological condition characterized by unexpectedly low reading ability despite adequate nonverbal intelligence and typical schooling. The neural correlates of handwriting deficits remain largely unknown; however, as well as the extent that handwriting deficits share common neural bases with reading deficits in DD. The present work used functional magnetic resonance imaging to examine brain activity during handwriting and reading tasks in Chinese dyslexic children (n = 18) and age-matched controls (n = 23). Compared to controls, dyslexic children exhibited reduced activation during handwriting tasks in brain regions supporting sensory-motor processing (including supplementary motor area and postcentral gyrus) and visual-orthography processing (including bilateral precuneus and right cuneus). Among these regions, the left supplementary motor area and the right precuneus also showed a trend of reduced activation during reading tasks in dyslexics. Moreover, increased activation was found in the left inferior frontal gyrus and anterior cingulate cortex in dyslexics, which may reflect more efforts of executive control to compensate for the impairments of motor and visual-orthographic processing. Finally, dyslexic children exhibited aberrant functional connectivity among brain areas for cognitive control and sensory-motor processes during handwriting tasks. Together, these findings suggest that handwriting deficits in DD are associated with functional abnormalities of multiple brain regions implicated in motor execution, visual-orthographic processing, and cognitive control, providing important implications for the diagnosis and treatment of dyslexia.
