Quantitative multidimensional phenotypes improve genetic analysis of laterality traits.

Handedness is the most commonly investigated lateralised phenotype and is usually measured as a binary left/right category. Its links with psychiatric and neurodevelopmental disorders prompted studies aimed at understanding the underlying genetics, while other measures and side preferences have been less studied. We investigated the heritability of hand, as well as foot, and eye preference by assessing parental effects (n ≤ 5028 family trios) and SNP-based heritability (SNP-h, n ≤ 5931 children) in the Avon Longitudinal Study of Parents and Children (ALSPAC).

Electroencephalography decoding of Chinese characters in primary school children and its prediction for word reading performance and development.

Research on what neural mechanisms facilitate word reading development in non-alphabetic scripts is relatively rare. The present study was among the first to adopt a multivariate pattern classification analysis to decode electroencephalographic signals recorded for primary school children (N = 236) while performing a Chinese character decision task. Chinese is an ideal script for studying the relationship between neural discriminability (i.

Study of Genetic Association With and Developmental Dyslexia in Hong Kong Chinese Children.

Background: Doublecortin domain-containing 2 (DCDC2) is a doublecortin domain-containing gene family member and the doublecortin domain has been demonstrated to bind to tubulin and enhance microtubule polymerization. It has been associated with developmental dyslexia and this protein family member is thought to function in neuronal migration where it may affect the signaling of primary cilia.

Objectives: The objective of the study is to find out if there is any association of genetic variants of DCDC2 with developmental dyslexia in Chinese children from Hong Kong.

Auditory perception and word recognition in Cantonese-Chinese speaking children with and without Specific Language Impairment.

Auditory processing and spoken word recognition difficulties have been observed in Specific Language Impairment (SLI), raising the possibility that auditory perceptual deficits disrupt word recognition and, in turn, phonological processing and oral language. In this study, fifty-seven kindergarten children with SLI and fifty-three language-typical age-matched controls were assessed with a speech-gating task to measure spoken word recognition, psychophysical tasks to measure auditory Frequency Modulation (FM) detection and Frequency Discrimination (FD), and standardized psychometric tests of phonological processing and oral language. As a group, children with SLI took significantly longer than language-typical controls to recognize words with high neighborhood density, perhaps reflecting subpar phonological representations.

Defective Number Sense or Impaired Access? Differential Impairments in Different Subgroups of Children With Mathematics Difficulties.

Developmental dyscalculia (DD) is a specific learning disability in mathematics that affects around 6% of the population. Currently, the core deficit of DD remains unknown. While the number sense deficit hypothesis suggests that the core deficit of DD lies in the inability to represent nonsymbolic numerosity, the access deficit hypothesis suggests that the origin of this disability lies in the inability to associate numbers with the underlying magnitude representation.

Syntactic and discourse skills in Chinese adolescent readers with dyslexia: a profiling study.

This study aims to investigate the relation of syntactic and discourse skills to morphological skills, rapid naming, and working memory in Chinese adolescent readers with dyslexia and to examine their cognitive-linguistic profiles. Fifty-two dyslexic readers (mean age, 13;42) from grade 7 to 9 in Hong Kong high schools were compared with 52 typically developing readers of the same chronological age (mean age, 13;30) in the measures of word reading, 1-min word reading, reading comprehension, morpheme discrimination, morpheme production, morphosyntactic knowledge, sentence order knowledge, digit rapid naming, letter rapid naming, backward digit span, and non-word repetition. Results showed that dyslexic readers performed significantly worse than their peers on all the cognitive-linguistic tasks.

Contrasting deficits on executive functions in Chinese delinquent adolescents with attention deficit and hyperactivity disorder symptoms and/or reading disability.

Many studies reported high prevalence of reading disability (RD) and attention deficit hyperactivity disorder (ADHD) among delinquent adolescents. Very few have examined their cognitive profile. The present study compared the executive functions (EFs) and severity of delinquency in delinquent adolescents with RD and/or ADHD symptoms (AS).

Identification of children with mathematics learning disabilities (MLDs) using latent class growth analysis.

The traditional way of identifying children with mathematics learning disabilities (MLDs) using the low-achievement method with one-off assessment suffers from several limitations (e.g., arbitrary cutoff, measurement error, lacking consideration of growth).

Contributions of syntactic awareness to reading in Chinese-speaking adolescent readers with and without dyslexia.

This study investigated the relative contribution of syntactic awareness to Chinese reading among Chinese-speaking adolescent readers with and without dyslexia. A total of 78 junior high school students in Hong Kong, 26 dyslexic adolescent readers, 26 average adolescent readers of the same age (chronological age control group) and 26 younger readers matched with the same reading level (reading-level group) participated and were administered measures of IQ, syntactic awareness, morphological awareness, vocabulary knowledge, working memory, word reading, and reading comprehension. Results showed that dyslexic readers scored significantly lower than chronological age but similarly to reading level control groups in most measures, especially in the areas of syntactic skills.

Cognitive skills and literacy performance of Chinese adolescents with and without dyslexia.

The present study sought to identify cognitive abilities that might distinguish Hong Kong Chinese adolescents with dyslexia and to assess how these abilities were associated with Chinese word reading, word dictation, and reading comprehension. The cognitive skills of interest were morphological awareness, visual-orthographic knowledge, rapid naming, and verbal working memory. A total of 90 junior secondary school students, 30 dyslexic, 30 chronological age controls, and 30 reading level controls was tested on a range of cognitive and literacy tasks.

Association of the rs3743205 variant of DYX1C1 with dyslexia in Chinese children.

Background: Dyslexia is a learning disability that is characterized by difficulties in the acquisition of reading and spelling skills independent of intelligence, motivation or schooling. Studies of western populations have suggested that DYX1C1 is a candidate gene for dyslexia. In view of the different languages used in Caucasian and Chinese populations, it is therefore worthwhile to investigate whether there is an association of DYX1C1 in Chinese children with dyslexia.

The nature of the automatization deficit in Chinese children with dyslexia.

Clarifying whether automatization deficits constitute the primary causes or symptoms of developmental dyslexia, we focused on three critical issues of the dyslexic automatization deficit, namely universality, domain specificity, and severity. Thirty Chinese dyslexic children (mean age 10 years and 5 months), 30 chronological-age-, and 30 reading-level-matched children were tested in 4 areas of automaticity: motor, visual search, Stroop facilitation effects, and automatic word recognition. The results showed that the dyslexic children performed significantly worse than the CA-controls but not the RL-controls in all the tasks except for Stroop congruent-color words, on which they performed worse than children in both control groups.

Perception of tone and aspiration contrasts in Chinese children with dyslexia.

Background: Previous research has shown a relationship between speech perception and dyslexia in alphabetic writing. In these studies speech perception was measured using phonemes, a prominent feature of alphabetic languages. Given the primary importance of lexical tone in Chinese language processing, we tested the extent to which lexical tone and aspiration, two fundamental dimensions of Cantonese speech not represented in writing, would distinguish dyslexic from non-dyslexic 8-year-old Chinese children.

The role of visual and auditory temporal processing for Chinese children with developmental dyslexia.

This study examined temporal processing in relation to Chinese reading acquisition and impairment. The performances of 26 Chinese primary school children with developmental dyslexia on tasks of visual and auditory temporal order judgement, rapid naming, visual-orthographic knowledge, morphological, and phonological awareness were compared with those of 26 reading level ability controls (RL) and 26 chronological age controls (CA). Dyslexic children performed worse than the CA group but similar to the RL group on measures of accurate processing of auditory and visual-order stimuli, rapid naming, morphological awareness, and phonological awareness and a minority performed worse on the two temporal processing tasks.

In search of subtypes of Chinese developmental dyslexia.

The dual-route model offers a popular way to classify developmental dyslexia into phonological and surface subtypes. The current study examined whether this dual-route model could provide a framework for understanding the varieties of Chinese developmental dyslexia. Three groups of Chinese children (dyslexics, chronological-age controls, and reading-level controls) were tested on Chinese exception character reading, pseudocharacter reading (analogous to English nonword reading), novel word learning, and some phonological and orthographic skills.