Chinese Developmental Dyslexia Research Articles

Clinical diagnostic practices for Chinese developmental dyslexia

Objective: To explore the optimization of the standardized assessment tool for clinical diagnosis of Chinese developmental dyslexia (DD). Methods: A cross-sectional study was conducted from May to December 2023, in which 130 primary school children in grades 1 to 3 with clinical signs of literacy lag and positive screening results on the screening scales were recruited from the outpatient clinic of Child Health Care Medical Division, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine. Chinese dyslexia screening behavior checklist for primary students (CDSBC) was used as the screening scales, and supplemented by dyslexia checklist for Chinese children. Referring to the standard procedure of the"expert advice on diagnosis and intervention of chinese developmental dyslexia", the developmental dyslexia scale for standard mandarin (DDSSM) was used to evaluate the children's literacy-related cognitive abilities and conduct the diagnostic assessment, and divided the children into learning backward group and the DD group. The t-test and χ2 test were used to compare the differences in the distribution of intelligence, literacy and attention deficit hyperactivity disorder between the two groups. Spearman's correlation was used to analyze the correlation between the scores for each cognitive ability in the DDSSM and the CDSBC. Results: Of the 130 children, 90 were male, aged (8.3±1.0) years; 40 were female, aged (8.1±0.9) years. A final diagnosis of DD was made in 59 cases, of which 41 were males. There was no statistically significant difference in operational intelligence quotient (101±15 vs.100±15, t=0.53, P>0.05) and statistically significant difference in literacy of DDSSM (32±5 vs.21±4, t=11.56, P<0.001) between the learning backward group and the DD group. Eighteen cases (25.4%) of the learning backward group were children with attention deficit subtype attention deficit hyperactivity disorder (ADHD-I), and 16 cases (27.1%) in DD group, the difference in incidence between the two groups was not statistically significant (χ2=0.05, P>0.05). There were correlations between the DDSSM (for oral vocabulary, morphological awareness and orthographic awareness) and the CDSBC total score (r=-0.42, -0.32, -0.35, all P<0.01), but the correlations for visuospatial perception and rapid automatized naming with CDSBC total score were not statistically significant (r=-0.09 and -0.20,both P>0.05). Conclusions: For literacy-related cognitive abilities, screening scales CDSBC are not sufficiently useful for assessment, so the introduction of standardized assessment tools DDSSM is an optimization of the clinical diagnosis of Chinese DD, which is crucial for achieving accurate diagnosis and intervention.

DysDiTect: Dyslexia Identification Using CNN-Positional-LSTM-Attention Modeling with Chinese Dictation Task.

Handwriting difficulty is a defining feature of Chinese developmental dyslexia (DD) due to the complex structure and dense information contained within compound characters. Despite previous attempts to use deep neural network models to extract handwriting features, the temporal property of writing characters in sequential order during dictation tasks has been neglected. By combining transfer learning of convolutional neural network (CNN) and positional encoding with the temporal-sequential encoding of long short-term memory (LSTM) and attention mechanism, we trained and tested the model with handwriting images of 100,000 Chinese characters from 1064 children in Grades 2-6 (DD = 483; Typically Developing [TD] = 581). Using handwriting features only, the best model reached 83.2% accuracy, 79.2% sensitivity, 86.4% specificity, and 91.2% AUC. With grade information, the best model achieved 85.0% classification accuracy, 83.3% sensitivity, 86.4% specificity, and 89.7% AUC. These findings suggest the potential of utilizing machine learning technology to identify children at risk for dyslexia at an early age.

Home reading environment, sociometric and demographic factors associated with dyslexia in primary school students in China: A case-control study

BackgroundDevelopmental dyslexia (DD) has been generally recognized as a multifactorial psychological disorder in recent decades. However, studies on reading and learning environment, social and demographic factors affecting Chinese developmental dyslexia (DD) are still scarce in China. This study aims to explore multidimensional home influencing factors associated with DD before and after birth. MethodsA total of 60 dyslexic and 252 normal elementary school students graded 2–5 were recruited in Shantou, China. The Least Absolute Shrinkage and Selection Operator (LASSO) regression model was used for the social and demographic variables screening. Odds ratios (ORs) with 95 % confidence intervals (CIs) for associations between DD and related factors were estimated by multivariate logistic regression models. ResultsThrough LASSO regression, we ultimately identified 13 key variables, including maternal education level and family monthly income, among others. The logistic regression analyses showed that the risk of DD was higher in children with lower maternal education levels. Divergent parenting styles may be a risk factor for developing DD as opposed to consistent parenting styles (OR = 4.93, 95%CI: 1.11–21.91). Children whose mothers suffered from malnutrition during pregnancy were more likely to develop DD (OR = 10.31, 95%CI: 1.84–37.86), as well as exposure to second-hand smoking at home every day (OR = 5.33, 95%CI: 1.52–18.66). Interestingly, children's active reading (OR = 0.26, 95%CI: 0.08–0.84; OR = 0.17, 95%CI: 0.04–0.76 for “sometimes” and “often” compared to none, respectively), children having extracurricular reading fairy tale books (OR = 0.37, 95%CI: 0.15–0.90), and children having extracurricular reading composition books (OR = 0.25, 95%CI: 0.09–0.69) were significant protective factors for DD. ConclusionsHome reading environment, several educational, sociometric and demographic factors may influence the development of dyslexia. We should pay attention to these factors on the development of dyslexia, so as to provide the well social and familial environment to ensure the healthy development of children.

Pathogenesis of Comorbid ADHD and Chinese Developmental Dyslexia: Evidence From Eye-Movement Tracking and Rapid Automatized Naming

Background: ADHD and Chinese developmental dyslexia (DD) have a very high comorbidity rate; however, which cognitive deficits characterize the comorbidity and when they occur during cognitive processing are still under debate. Methods: Rapid automatic naming (RAN) tasks with eye-movement tracking were conducted with 75 children who were typically developing, had comorbid ADHD and DD, had only ADHD, and had only DD. Results: The clinical groups had longer first fixation durations than the control for RAN digits. Temporal eye-movement measures, such as gaze duration and total reading time, were found to vary between the comorbidity and ADHD groups. Spatial eye-movement measures, such as regression probability and incoming saccade amplitude, differed between the comorbidity and DD groups. Conclusions: These results indicate that investigation with eye-movement measures combined with RAN tasks can strengthen the understanding of the pathogenesis of comorbid ADHD and DD.

Features of eye movements during rapid automatized naming in Chinese children aged 7-11 years.

Rapid Automatized Naming (RAN) tests have been well-documented to predict reading abilities as well as a variety of neurobiological disorders (e.g., developmental dyslexia). Traditional measures of RAN tests only take into account the naming time and accuracy and cannot reflect temporal-spatial features during RAN tests. Although the eye tracking approach appears to be a promising tool for characterizing the essential temporal-spatial characteristics of RAN tests, no research has been conducted to investigate whether and how gender, age, and task-type alter those characteristics. Additionally, no study has examined eye movements during a Chinese adaptation of RAN in order to expand the applicability of RAN to developmental dyslexia in Chinese. To address the concerns stated above, this article recruited 408 children (206 males, aged 7-11 years) and adopted eight measures to quantify features of eye movements during a Chinese adaptation of RAN. Findings showed that: (1) eight eye-movement measures had the main effects of task-type and age, but only five of them had the main effect of gender (in particular, females outperformed males); (2) RAN abilities observed by eight eye-movement measures initially developed quickly before the age of 9, and then entered a relatively sluggish development phase; (3) non-alphanumeric RAN tasks generally required higher mental load (implying more fixation counts, saccade counts, and regression counts, smaller average saccade amplitude, fixation duration fluctuation and saccade amplitude fluctuation, and longer average fixation duration and total time of naming) than alphanumeric ones; (4) there were significant correlations between total time of naming (a widely-used behavioral parameter) and other eye-movement measures; and (5) there were significant correlation between eight eye-movement measures and three attention-related skills observed from a number cancellation task. The current study might offer some perspectives on the understanding of normative data of eye movements during RAN in Chinese school-aged children, as well as the applications (e.g., developmental dyslexia) associated with RAN.

Recent Advances in Chinese Developmental Dyslexia

Chinese developmental dyslexia (DD) research provides important insights into the language-universal and language-specific mechanisms underlying dyslexia. In this article, we review recent advances in Chinese DD. Converging behavioral evidence suggests that, while phonological and rapid automatized naming deficits are language universal, orthographic and morphological deficits are specific to the linguistic properties of Chinese. At the neural level, hypoactivation in the left superior temporal/inferior frontal regions in dyslexic children across Chinese and alphabetic languages may indicate a shared phonological processing deficit, whereas hyperactivation in the right inferior occipital/middle temporal regions and atypical activation in the left frontal areas in Chinese dyslexic children may indicate a language-specific compensatory strategy for impaired visual-spatial analysis and a morphological deficit in Chinese DD, respectively. The findings call for further theoretical endeavors to understand the language-universal and Chinese-specific neurobiological mechanisms underlying dyslexia and to design more effective and efficient intervention programs.

Quality of life in Chinese children with developmental dyslexia: a cross-sectional study

ObjectivesOur study aimed to compare the quality of life (QoL) between Chinese developmental dyslexia (DD) and healthy children.DesignA cross-sectional study.SettingThe participants were recruited from grades 3–6 in six primary schools...

Orthographic Processing of Developmental Dyslexic Children in China: Evidence from an Event-Related Potential Study.

This study aimed to explore the orthographic processing of simplified Chinese characters in developmental dyslexic children in Kashgar, Xinjiang, China, and provide a theoretical basis for intervention strategies for developmental dyslexia in Chinese. Using event-related potential (ERP) measures, 18 developmental dyslexic children and 23 typically developing children performed a character decision task with three types of stimuli: real characters (RCs), pseudocharacters (PCs), and noncharacters (NCs). Behavioral results showed that the control children displayed a faster and higher accurate performance than the dyslexic children across PCs and NCs. ERP data revealed that the RCs and PCs elicited a stronger P200 than the NCs. Compared with the RCs and NCs, children in the control group showed more N400 negatives for PCs. It is worth mentioning that dyslexic children did not show any difference on N400, which reflected the insufficient orthographic processing of dyslexic children in China. These results show that Chinese dyslexic children had orthographic processing defects.

Visual attention span and phonological skills in Chinese developmental dyslexia

BackgroundIt has been debated whether visual attention span deficit was independent from phonological deficit in alphabetic developmental dyslexia. Yet, this issue has never been examined in Chinese developmental dyslexia. AimThe aim of the present study was to concurrently investigate visual attention span deficit and phonological deficit in Chinese developmental dyslexia, and examine the relationship between them. MethodsA total of 45 Chinese dyslexic and 43 control children aged between 8 and 11 years old participated in this study. A visual one-back paradigm with both verbal stimuli (character and digit strings) and nonverbal stimuli (color dots and symbols) was employed for measuring visual attention span. Phonological skills were measured by three dimensions: phonological awareness, rapid automatized naming, and verbal short-term memory. ResultsChinese dyslexic children showed deficits in verbal visual attention span and all three dimensions of phonological skills, but not in nonverbal visual attention span. Phonological skills significantly contributed to explaining variance of reading skills and classifying dyslexic and control memberships. Almost all Chinese dyslexic participants who showed a deficit in visual attention span also showed a phonological deficit. ConclusionThe study suggests that visual attention span deficit is not independent from phonological deficit in Chinese developmental dyslexia.

汉语发展性阅读障碍的研究进展

汉语发展性阅读障碍的研究进展

The Prevalence of Dyslexia in Primary School Children and Their Chinese Literacy Assessment in Shantou, China.

The epidemiological studies of Chinese developmental dyslexia (DD) in China are still limited. In addition, literacy assessment has seldom been performed for children with dyslexia, due to lack of uniform assessment tools. This study was aimed at investigating the prevalence rate of children with dyslexia, and to evaluate their Chinese reading ability. A total of 2955 students aged 7–12 years were enrolled by randomized cluster sampling. The study was divided into three stages. In stage I, all participating students were asked to finish the Combined Raven Test (CRT) and Chinese Vocabulary Test and Assessment Scale. In stage II, the Chinese teachers and parents of the children with suspected dyslexia were interviewed by psychiatrists, and finished the Dyslexia Checklist for Chinese Children (DCCC). In stage III, these children were evaluated by child psychiatrists for the diagnosis with or without dyslexia, according to the fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-5), and their Chinese literacy was further evaluated by using the Chinese Reading Ability Test (CRAT). The prevalence rate of children with dyslexia was 5.4% in Shantou city, 8.4% in boys and 2.3% in girls, with a gender ratio of 3.7:1.0. Children with dyslexia scored lower in all the five subscales of the CRAT tests. including phonological awareness, morphological awareness, rapid automatized naming, orthographic awareness, and reading ability than the control group (all p < 0.001). This study suggested that the prevalence rate of Chinese dyslexia in Shantou city is roughly equivalent to that previously reported in China. Children with dyslexia have a relatively lower Chinese reading ability in all assessments.

Spelling in developmental dyslexia in Chinese: Evidence of deficits in statistical learning and over-reliance on phonology

ABSTRACT This study employed a multi-dimensional (i.e., orthographic, phonological, and semantic) and bi-level (i.e., character and radical) approach to analyze the character writing of 120 Hong Kong Chinese children with developmental dyslexia in Grades 2–5 and 120 typically developing age-matched controls. Relative to their typically developing peers, children with dyslexia were less sensitive to the positional and functional consistencies of sublexical radicals and exhibited prolonged use of phonology at the character level as grade-level advanced. Furthermore, the children with dyslexia relatively relied more on phonology at the radical level than younger, reading level-matched children. These results indicate the effects of implicit statistical learning on the development of Chinese character writing skills and suggest that the prolonged use and overreliance on phonology in character writing by Chinese children with dyslexia may reflect their difficulties in implicit statistical learning.

An Epidemiological Study of Chinese Children with Developmental Dyslexia.

The epidemiological studies of Chinese developmental dyslexia (DD) in China are still limited. The current study aimed to investigate the prevalence rate, risk factors, and psychiatric comorbidities of Chinese DD in Guangzhou, a city in South China. A total of 1661 students from second to fifth grades were recruited. The dyslexic students were identified by evaluating learning disability through the Pupil Rating Scale-Revised Screening for Learning Disability (PRS) scale by the head teachers and word recognition through the standard test. Students with a PRS score of <65 received the Raven's test, and those with intelligence quotient scores below 80 in the Raven's test were excluded. Psychiatric comorbidities were assessed by the Strength and Difficulties Questionnaire completed by parents. The prevalence rate of Chinese DD was 4.9% in Guangzhou city. There were significant differences in gender, the paternal educational level, and reading experience before the age of 6 years between the DD group and the non-DD group. Male gender (odds ratio [OR] = 4.17), low paternal educational level (p = 0.045), and lack of reading experience before the age of 6 years (OR = 1.99) were the risk factors for DD. The DD cases had a higher risk of hyperactivity and inattention (OR = 3.21). This study showed that the prevalence rate of DD was 4.9% in Guangzhou city. Male gender, low paternal educational level, and lack of reading experience before the age of 6 years were the risk factors for Chinese DD. The high comorbidity rate of hyperactivity and inattention in the Chinese DD population needs further evaluation.

Dyslexia associated functional variants in Europeans are not associated with dyslexia in Chinese.

Genome-wide association studies (GWAS) of developmental dyslexia (DD) often used European samples and identified only a handful associations with moderate or weak effects. This study aims to identify DD functional variants by integrating the GWAS associations with tissue-specific functional data and test the variants in a Chinese DD study cohort named READ. We colocalized associations from nine DD related GWAS with expression quantitative trait loci (eQTL) derived from brain tissues and identified two eSNPs rs349045 and rs201605. Both eSNPs had supportive evidence of chromatin interactions observed in human hippocampus tissues and their respective target genes ZNF45 and DNAH9 both had lower expression in brain tissues in schizophrenia patients than controls. In contrast, an eSNP rs4234898 previously identified based on eQTL from the lymphoblastic cell lines of dyslexic children had no chromatin interaction with its target gene SLC2A3 in hippocampus tissues and SLC2A3 expressed higher in the schizophrenia patients than controls. We genotyped the three eSNPs in the READ cohort of 372 cases and 354 controls and discovered only weak associations in rs201605 and rs4234898 with three DD symptoms (p < .05). The lack of associations could be due to low power in READ but could also implicate different etiology of DD in Chinese.

Auditory identification of frequency-modulated sweeps and reading difficulties in Chinese

BackgroundIn Chinese Mandarin, lexical tones play an important role of providing contrasts in word meaning. They are pitch patterns expressed by frequency-modulated (FM) signals. Yet, few studies have looked at the relationship between low-level auditory processing of frequency signals and Chinese reading skills. AimsThe study aims to identify the role of auditory frequency processing in Chinese lexical tone awareness as well as character recognition in Chinese-speaking children. MethodsChildren with (N = 28) and without (N = 27) developmental dyslexia (DD) were recruited. All participants completed two linguistic tasks, Chinese character recognition and lexical tone awareness, and two auditory frequency processing tasks, frequency discrimination and FM sweep direction identification. ResultsThe results revealed that Chinese-speaking children with DD were significantly poorer at all tasks. Particularly, Chinese character recognition was significantly related to FM sweep identification. Lexical tone awareness was significantly associated with both auditory frequency processing tasks. Regression analyses suggested the influence of FM sweep identification on Chinese character recognition contributed through lexical tone awareness. Conclusions and implicationThis study suggests that poor auditory frequency processing may associate with Chinese developmental dyslexia with phonological deficits. In support of the phonological deficit hypothesis, what underlies phonological deficit is likely to be auditory-basis. A potential clinical implication is to reinforce auditory perception and sensitivity through intervention for phonological processing.

Enhanced N170 elicited by words in Chinese developmental dyslexia.

Impaired print tuning in dyslexia has been shown in alphabetic languages; whether we can observe the same in a nonalphabetic language such as Chinese is still questionable. The present study investigated the N170 component in response to Chinese words versus nonword pseudo-words in 10-year-old children with developmental dyslexia (DD) when they were asked to performed a lexical decision task. The N170 was enhanced for DD group than control group, regardless of Chinese words or pseudo-words. The group effect of N170 amplitudes was more robust for Chinese words over pseudo-words. Although the N170 did not show the word advantage in the control group, larger N170 for Chinese words versus pseudo-words was found in the DD group. These findings suggest that there was a dysfunction/inefficient processing in the early stage of processing Chinese words in patients with DD.

Specifying the diffusion MRI connectome in Chinese-speaking children with developmental dyslexia and auditory processing deficits

Lexical tone identification has a unique role in the perceptual processes of Chinese readers. Reduced lexical tone awareness, along with poor word-decoding abilities, is frequently observed in Chinese-speaking children with developmental dyslexia. However, whether this deficit is linked to reduced auditory processing and interrupted structural connectivity in the brain requires further investigation. This study therefore explores the white matter pathways associated with Chinese character recognition and auditory processing of pitch variations, with the objective of to identify the most representative neural correlates for Chinese developmental dyslexia. Diffusion magnetic resonance imaging and several behavior measures related to reading attainment and phonological awareness were acquired in twenty-four Chinese-speaking children with developmental dyslexia and twenty-two age-matched controls. We used diffusion magnetic resonance imaging connectometry to explore the relationships between behavior performance and specific white matter tracts. The results revealed significant correlations of the left inferior fronto-occipital fasciculus, cerebellar pathways, and thalamopontine tracts with Chinese character recognition (FDR=0.03235). In addition, the posterior isthmus and anterior splenium of the corpus callosum correlated with auditory processing (FDR=0.03980). The study provides evidence that the dysconnectivity on white matter pathways correlated with developmental dyslexia in Chinese-speaking children. Furthermore, the impairments of auditory temporal timing processing presented in poor readers with significant phonological deficits are likely to be a result of impoverished myelinization in sub-cortical tracts. Such findings may assist in the clinical identification of Chinese developmental dyslexia.

Structural and functional abnormality of the putamen in children with developmental dyslexia

There is currently debate with regards to the role of phonological deficit in Chinese reading difficulty, even though some researchers have suggested that the deficit of phonological processing is also a signature of developmental dyslexia in Chinese, as has been found in alphabetic languages. In this study, we examined the brain mechanisms of phonological deficit in Chinese children with developmental dyslexia (DD) during an auditory rhyming judgment task. First, we examined structural differences in Chinese dyslexia by comparing gray and white matter volume in Chinese children with DD, age-matched controls (AC), and reading-matched controls (RC). Next, we examined whether the regions with an abnormal volume in DD showed deficient functional connectivity with the rest of the brain during a phonological task (i.e. auditory rhyming judgment). We found that both AC and RC had greater gray matter volume (GMV) at the left putamen and right dorsal lateral frontal cortex than DD, suggesting possible neural signatures of developmental dyslexia. Functional connectivity analysis revealed that the left putamen was more connected with the right inferior occipital gyrus (IOG) in AC and RC than in DD, suggesting that automatic orthographic involvement during spoken language processing is more salient in controls, while the left putamen was more connected with the left transverse temporal gyrus (TTG) and left insula in DD than in AC and RC, suggesting the phonological articulation –auditory feedback loop is more involved in DD. These findings suggest that the reduced left putamen might contribute to phonological deficits experienced in DD, since it showed deficient connectivity with the rest of the brain during phonological processing.

Examining the visual attention span deficit hypothesis in Chinese developmental dyslexia

The present study examines the visual attention span deficit hypothesis in Chinese developmental dyslexia. Twenty-five Cantonese-speaking Chinese dyslexic children (DD group) were compared with 25 chronological-age-matched (CA) controls and another 25 reading-level-matched (RL) controls on their performance in visual attention span, reading, and reading-related cognitive tasks. Results of analysis of variance showed that the DD group performed significantly worse than the CA group in most measures and less well than the RL group in the visual attention span character task. 68 and 52% of the dyslexic participants showed deficits in at least one visual attention span measure when compared with the CA group and the RL group respectively. Results of multiple regression analysis also showed that the composite score of visual attention span significantly predicted Chinese word reading accuracy, word and text reading fluency even after controlling for age, IQ, orthographic skills, and rapid naming. The present findings suggest that visual attention span deficit may be associated with developmental dyslexia in Chinese. The role of visual attention span for word and text reading in Chinese is above and beyond several known reading-related skills.

Alterations in white matter pathways underlying phonological and morphological processing in Chinese developmental dyslexia

Chinese is a logographic language that is different from alphabetic languages in visual and semantic complexity. Thus far, it is still unclear whether Chinese children with dyslexia show similar disruption of white matter pathways as in alphabetic languages. The present study focused on the alteration of white matter pathways in Chinese children with dyslexia. Using diffusion tensor imaging tractography, the bilateral arcuate fasciculus (AF-anterior, AF-posterior and AF-direct segments), inferior fronto-occipital fasciculus (IFOF) and inferior longitudinal fasciculus (ILF) were delineated in each individual’s native space. Compared with age-matched controls, Chinese children with dyslexia showed reduced fractional anisotropy in the left AF-direct and the left ILF. Further regression analyses revealed a functional dissociation between the left AF-direct and the left ILF. The AF-direct tract integrity was associated with phonological processing skill, an ability important for reading in all writing systems, while the ILF integrity was associated with morphological processing skill, an ability more strongly recruited for Chinese reading. In conclusion, the double disruption locus in Chinese children with dyslexia, and the functional dissociation between dorsal and ventral pathways reflect both universal and specific properties of reading in Chinese.