A Study Of Brain Network Based On Resting-state EEG In Chinese Dyslexic Children

Developmental dyslexia are a typical neurodevelopmental disorder.Revealing the neural basis of reading difficulties can provide evidence for understanding the underlying mechanism,identification and early diagnosis of this disorder.Reading is a complex and advanced process that involves multiple brain regions.Most previous studies have focused on functional connectivity or network analyses in a few specific brain areas,however,the characteristics of whole-brain functional networks in dyslexic children are still unclear.In addition,a large number of studies have found that resting-state brain network activity is a good tool to reveal the neural basis of brain diseases and neurodevelopmental disorders,but the characteristics of resting state whole brain functional network in dyslexic children(especially Chinese dyslexic children)are still lacking.Moreover,the cognitive significance of the brain network and the causal relationship between brain functional network defects and reading skills of dyslexic children are still unclear.Using EEG technology combining with the field of the latest development of minimum spanning tree(MST)of graph theory analysis method,the present study aimed to depict the resting-state whole brain function network characteristic of Chinese developmental dyslexic children and normal children of same age.Through cognitive measurements and the longitudinal design,this study further revealed the relationship between abnormal brain function network and reading-related cognitive skills.Study 1 used a control group design to investigate the metrics of MST and its correlation with reading-related cognitive skills in 27 dyslexic children and 40 normal children of the same age.The results showed that the brain function network of dyslexic children showed the deficiencies of whole-brain function network in the beta band and the network topology was a more path-like structure with low information exchange efficiency.In addition,the MST metrics of the theta band were correlated with rapid automatic naming and morpheme awareness.Using a longitudinal design,study 2 further examined the whole-brain functional network characteristics and reading-related cognitive abilities of 14 dyslexic children from grade 1 to grade 3.Results showed that,at the beginning of reading learning,the reading-related cognitive abilities of dyslexic children in the first grade were significantly lower than that of normal children.However,there was no significant difference in the MST metrics of whole-brain network between the two groups.With further learning to read,dyslexic children in the second and third grade had a more path-like topology,and the defect manifests not only in beta and theta,but also in delta and alpha band.These results suggested that whole-brain functional network deficits may be the outcome of impaired reading skill acquisition.In addition,the second-grade children’s brain function network metrics were related to visual-spatial processing abilities,while the third-grade children’s brain function network metrics were related to morpheme awareness.In conclusion,this study found that a less efficient network configuration locus in Chinese dyslexic children and the network topology was more path-like.Moderate correlations were observed between MST metrics and rapid automatized naming and morphological awareness and visual-spatial scores.These observations provide new evidence for understanding the neural basis of developmental dyslexia,and guidance for the diagnosis and intervention of dyslexic children.