Home | Sitemap | Contact | 中文 | CAS
Search: 
About Us
Research
Scientists
International Cooperation
News
Education & Training
Join Us
Societies & Publications
Papers
Resources
Location:Home>Research>Research Progress
 
Scientists Reveal Handwriting Deficits in Dyslexia are Associated with Abnormal Brain Activation and Functional Connectivity
 
Author: Dr.YANG Yang      Update time: 2021/09/02
Close
Text Size: A A A
Print

Reading is key to human communication and literacy development. Developmental dyslexia is a neurological learning disability characterized by significantly low reading achievement based on chronological age, despite adequate intelligence and socioeconomic opportunity. It affects approximately 5%-17% of school-aged children. Ample evidence has shown that handwriting disability is a persistent problem in dyslexia (e.g., more pauses between words and within words). Handwriting difficulty in dyslexia may become more severe due to the dramatic reduction of handwriting practice in daily life in the digital age.

Handwriting is a complex process involving linguistic, attentional and perceptual-motor processes. 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 dyslexia. To fill this research gap, Dr. YANG Yang from Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences and his colleagues conducted a study to examine brain activity during handwriting and reading tasks in Chinese dyslexic children and age-matched controls. 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.

Figure 1 Brain activation results in the handwriting tasks. Lateral surface-rendered views of brain activation during handwriting and drawing in controls (A) and in dyslexics (B). Lateral surface-rendered views of brain regions showing reduced activation (C) and increased activation (D) during handwriting characters in dyslexics compared to controls. Delayed_H = delayed copying of high-frequency characters; Delayed_L = delayed copying of low-frequency characters; Direct_L = direct copying of low-frequency characters; Delayed_F = delayed drawing of figures; Precun = precuneus; SFG = superior frontal gyrus; SMA = supplementary motor area; PostCG = postcentral gyrus; IFG = inferior frontal gyrus; Ant Cing = anterior cingulate gyrus; L = left; R = right.  Image by YANG Yang.

Together, these findings suggest that handwriting deficits in dyslexics 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.

This study entitled “The brain basis of handwriting deficits in Chinese children with developmental dyslexia” has been published on July 20, 2021 in Developmental Science:

Yang, Y., Zuo, Z., Tam, F., Graham, S. J., Li, J., Ji Y., Meng Z., Gu, C., Bi, H.Y., Ou, J., & Xu, M. (2021). The brain basis of handwriting deficits in Chinese children with developmental dyslexia. Developmental Science.

LIU Chen
Institute of Psychology
Chinese Academy of Sciences
Beijing 100101, China.
E-mail: liuc@psych.ac.cn


 

16 Lincui Road, Chaoyang District, Beijing 100101, China. All Rights Reserved