A genome-wide association study of Chinese and English language phenotypes in Hong Kong Chinese children.

Dyslexia and developmental language disorders are important learning difficulties. However, their genetic basis remains poorly understood, and most genetic studies were performed on Europeans. There is a lack of genome-wide association studies (GWAS) on literacy phenotypes of Chinese as a native language and English as a second language (ESL) in a Chinese population. In this study, we conducted GWAS on 34 reading/language-related phenotypes in Hong Kong Chinese bilingual children (including both twins and singletons; total N = 1046). We performed association tests at the single-variant, gene, and pathway levels. In addition, we tested genetic overlap of these phenotypes with other neuropsychiatric disorders, as well as cognitive performance (CP) and educational attainment (EA) using polygenic risk score (PRS) analysis. Totally 5 independent loci (LD-clumped at r2 = 0.01; MAF > 0.05) reached genome-wide significance (p < 5e-08; filtered by imputation quality metric Rsq>0.3 and having at least 2 correlated SNPs (r2 > 0.5) with p < 1e-3). The loci were associated with a range of language/literacy traits such as Chinese vocabulary, character and word reading, and rapid digit naming, as well as English lexical decision. Several SNPs from these loci mapped to genes that were reported to be associated with EA and other neuropsychiatric phenotypes, such as MANEA and PLXNC1. In PRS analysis, EA and CP showed the most consistent and significant polygenic overlap with a variety of language traits, especially English literacy skills. To summarize, this study revealed the genetic basis of Chinese and English abilities in a group of Chinese bilingual children. Further studies are warranted to replicate the findings.

WordSword: An Efficient Online Word Reading Assessment for Global English.

The development of efficient and reliable online assessments has become increasingly important in the digital era. We developed a 10-min online word reading assessment of global English based on the existing paper-and-pencil version of our English silent word reading test. The test includes two parts, namely, random word recognition and contextual word reading. A total of 889 participants (437 children and 392 adults; 62.7% female) took part in the study. They were from various regions including mainland China, Hong Kong SAR, Macau SAR, Poland, the United States, and the Philippines. Reliability and validity analyses on various demographics samples (by age and country/region of origin) demonstrated that the WordSword Test is highly reliable and valid (e.g., the correlation of this test with other English reading measures were above .80). Education level was positively correlated with test performance, while the correlations between age and test performance were not consistent. Ninety-seven children participants also took the paper-and-pencil version of the WordSword Test. The correlation between performances on the online and paper-and-pencil versions of the test was .879, one year apart. With more children and adults taking the WordSword Test, we ultimately hope to establish norms by area, grade level, and age.

Reduction in right lateralized N2 error response to stroke order violations in poor Chinese word spellers: A study on event-related potential markers for Chinese reading and spelling.

Stroke order knowledge is critical for Chinese reading and spelling acquisition. Previous studies have demonstrated enhancements of the N2 and P3 event-related potential (ERP) components at the Pz electrode to stroke order violations of Chinese characters in younger adults. However, it remained unclear whether similar ERP responses could be found in children. The current study investigated the ERP responses to stroke order violations of Chinese characters in children and examined the associations of the ERP responses with children's Chinese reading and spelling performance. A total of 26 Grade 2 Hong Kong Chinese children observed stroke-by-stroke displays of Chinese characters and judged whether the Chinese characters were written in the correct order. The ERP results showed larger anterior N2 and posterior P3 at the midline electrodes to the incorrect strokes than to the correct strokes. In addition, a smaller right lateralized temporal N2 response to the incorrect strokes was found in poor spellers as compared with good spellers of Chinese. The effect of the right lateralized temporal N2 response on reading performance was fully mediated through spelling ability. These results demonstrated increases in the anterior N2 and posterior P3 responses to stroke order violation of Chinese characters in second graders and suggest the right lateralized N2 response as a potential neural marker of Chinese literacy development in children.

Spelling as a way to classify poor Chinese-English literacy skills in Hong Kong Chinese children.

Previous work has predominantly focused on word reading in studying literacy difficulties; very little work has focused on spelling difficulty instead. The present study adopted spelling (dictation) as the criterion to classify poor literacy skills in Hong Kong Chinese-English bilingual children. We examined the cognitive-linguistic skills profiles across four groups of children with different spelling abilities. Based on performances on Chinese and English dictation (criterion = below 25% in a larger sample), four groups were identified, 21 poor spellers of Chinese (PC), 18 poor spellers of English (PE), 27 poor spellers of both languages (PB), and 30 good spellers of both scripts (GB). Measures on language-specific tests of cognitive-linguistic skills (phonological awareness, lexical decision, morphological awareness, rapid naming, and delayed copying) were included to compare the degree of deficit exhibited by each group. With age, grade, and non-verbal intelligence controlled, one-way ANCOVA results revealed that, compared to GB, PC manifested significant deficits in Chinese-delayed copying but scored similarly on all English cognitive-linguistic skills. PE and PB showed significant deficits in Chinese and English phonological awareness compared to PC; they were significantly weaker in English-delayed copying, morphological awareness, and rapid naming (RAN). The PB group was significantly slower in both Chinese and English RAN compared to GB. Findings highlight the critical role of delayed copying in distinguishing poor spellers in both Chinese and English, the importance of phonological awareness for spelling in English but not in Chinese, and the role of automaticity in bilingual spelling difficulties.

Resting state EEG network modularity predicts literacy skills in L1 Chinese but not in L2 English.

EEG network modularity, as a proxy for cognitive plasticity, has been proposed to be a more reliable neural marker than power and coherence in predicting learning outcomes. The present study examined the associations between resting state EEG network modularity and both L1 Chinese and L2 English literacy skills among 90 Hong Kong first to fifth graders. The modularity indices of different frequency bands were highly correlated with one another. An exploratory factor analysis, performed to extract a general modularity index, explained 77.1% of the total variance. The modularity index was positively associated with Chinese word reading, Chinese phonological awareness, Chinese morphological awareness, and Chinese reading comprehension but was not significantly correlated with English word reading or English morphological awareness. Findings suggest that resting state EEG network modularity is likely to serve as a reasonable, reliable, and cost-effective neural marker of the development of first language but not second language literacy skills.