Neural signatures of phonological deficits in Chinese developmental dyslexia

An abbreviated Chinese dyslexia screening behavior checklist for primary school students using a machine learning approach

To increase early identification and intervention of dyslexia, a prescreening instrument is critical to identifying children at risk. The present work sought to shorten and validate the 30-item Mandarin Dyslexia Screening Behavior Checklist for Primary School Students (the full checklist; Fan et al., , 19, 521-527, 2021). Our participants were 15,522 Mandarin-Chinese-speaking students and their parents, sampled from classrooms in grades 2-6 across regions in mainland China. A machine learning approach (lasso regression) was applied to shorten the full checklist (Fan et al., , 19, 521-527, 2021), constructing grade-specific brief checklists first, followed by a compilation of the common brief checklist based on the similarity across grade-specific checklists. All checklists (the full, grade-specific brief, and common brief versions) were validated and compared with data in our sample and an external sample (N = 114; Fan et al., , 19, 521-527, 2021). The results indicated that the six-item common brief checklist showed consistently high reliability (αs > .82) and reasonable classification performance (about 60% prediction accuracy and 70% sensitivity), comparable to that of the full checklist and all grade-specific brief checklists across our current sample and the external sample from Fan et al., , 19, 521-527, (2021). Our analysis showed that 2.42 (out of 5) was the cutoff score that helped classify children's reading status (children who scored higher than 2.42 might be considered at risk for dyslexia). Our final product is a valid, accessible, common brief checklist for prescreening primary school children at risk for Chinese dyslexia, which can be used across grades and regions in mainland China.

Neural Mechanisms of Learning and Consolidation of Morphologically Derived Words in a Novel Language: Evidence From Hebrew Speakers

We examined neural mechanisms associated with the learning of novel morphologically derived words in native Hebrew speakers within the Complementary Learning Systems (CLS) framework. Across four sessions, 28 participants were trained on an artificial language, which included two types of morphologically complex words: linear (root + suffix) with a salient structure, and non-linear (root interleaved with template), with a prominent derivational structure in participants' first language (L1). A third simple monomorphemic condition, which served as baseline, was also included. On the first and fourth sessions, training was followed by testing in an fMRI scanner. Our behavioural results showed decomposition of both types of complex words, with the linear structure more easily learned than the non-linear structure. Our fMRI results showed involvement of frontal areas, associated with decomposition, only for the non-linear condition, after just the first session. We also observed training-related increases in activation in temporal areas specifically for the non-linear condition, which was correlated with participants' L1 morphological awareness. These results demonstrate that morphological decomposition of derived words occurs in the very early stages of word learning, is influenced by L1 experience, and can facilitate word learning. However, in contrast to the CLS framework, we found no support for a shift from reliance on hippocampus to reliance on cortical areas in any of our conditions. Instead, our findings align more closely with recent theories showing a positive correlation between changes in hippocampus and cortical areas, suggesting that these representations co-exist and continue to interact with one another beyond initial learning.

Abnormal brain activation during speech perception and production in children and adults with reading difficulty

Reading difficulty (RD) is associated with phonological deficits; however, it remains unknown whether the phonological deficits are different in children and adults with RD as reflected in foreign speech perception and production. In the current study, using functional Near-infrared spectroscopy (fNIRS), we found less difference between Chinese adults and Chinese children in the RD groups than the control groups in the activation of the right inferior frontal gyrus (IFG) and the dorsolateral prefrontal cortex (DLPFC) during Spanish speech perception, suggesting slowed development in these regions associated with RD. Furthermore, using multivariate pattern analysis (MVPA), we found that activation patterns in the left middle temporal gyrus (MTG), premotor, supplementary motor area (SMA), and IFG could serve as reliable markers of RD. We provide both behavioral and neurological evidence for impaired speech perception and production in RD readers which can serve as markers of RD.

Shared and task-specific brain functional differences across multiple tasks in children with developmental dyslexia

Different tasks have been used in examining the neural functional differences associated with developmental dyslexia (DD), and consequently, different findings have been reported. However, very few studies have systematically compared multiple tasks in understanding what specific task differences each brain region is associated with. In this study, we employed an auditory rhyming task, a visual rhyming task, and a visual spelling task, in order to investigate shared and task-specific neural differences in Chinese children with DD. First, we found that children with DD had reduced activation in the opercular part of the left inferior frontal gyrus (IFG) only in the two rhyming tasks, suggesting impaired phonological analysis. Children with DD showed functional differences in the right lingual gyrus/inferior occipital gyrus only in the two visual tasks, suggesting deficiency in their visuo-orthographic processing. Moreover, children with DD showed reduced activation in the left dorsal inferior frontal gyrus and increased activation in the right precentral gyrus across all of the three tasks, suggesting neural signatures of DD in Chinese. In summary, our study successfully separated brain regions associated with differences in orthographic processing, phonological processing, and general lexical processing in DD. It advances our understanding about the neural mechanisms of DD.

The mechanism of phonetic information in voice identity discrimination: a comparative study based on sighted and blind people

Purpose

The purpose of this study is to examine whether phonetic information functions and how phonetic information affects voice identity processing in blind people.

Method

To address the first inquiry, 25 normal sighted participants and 30 blind participants discriminated voice identity, when listening forward speech and backward speech from their own native language and another unfamiliar language. To address the second inquiry, combining articulatory suppression paradigm, 26 normal sighted participants and 26 blind participants discriminated voice identity, when listening forward speech from their own native language and another unfamiliar language.

Results

In Experiment 1, not only in the voice identity discrimination task with forward speech, but also in the discrimination task with backward speech, both the sighted and blind groups showed the superiority of the native language. This finding supports the view that backward speech still retains some phonetic information, and indicates that phonetic information can affect voice identity processing in sighted and blind people. In addition, only the superiority of the native language of sighted people was regulated by the speech manner, which is related to articulatory rehearsal. In Experiment 2, only the superiority of the native language of sighted people was regulated by articulatory suppression. This indicates that phonetic information may act in different ways on voice identity processing in sighted and blind people.

Conclusion

The heightened dependence on voice source information in blind people appears not to undermine the function of phonetic information, but it appears to change the functional mechanism of phonetic information. These findings suggest that the present phonetic familiarity model needs to be improved with respect to the mechanism of phonetic information.

What Factors Contribute to Reading in ADHD: Examining Reading-Related Skills in Children With ADHD Only/Comorbid Developmental Dyslexia

BACKGROUND

ADHD and developmental dyslexia (DD) frequently co-occur. However, it is unclear why some children with ADHD acquire DD while others do not.

METHODS

A total of 830 children (including typically developing controls, ADHD only, DD only, and ADHD + DD groups) of two ages (younger: first-third grade; older: fourth-sixth grade) were assessed on measures of reading ability and reading-related skills.

RESULTS

The clinical groups had different degrees of impairment in each reading-related skill. Regression results found that the four groups had different skills in predicting reading ability in younger and older grades. Especially, rapid automatized naming (RAN) was the only predictor of reading ability in children with ADHD only.

CONCLUSIONS

The study highlights that RAN plays an important role in the reading development of children with ADHD only, reflecting the possible protective role of RAN in reading development.

Reading Fluency in Chinese Children With Reading Disabilities and/or ADHD: A Key Role for Morphology

The Triangle Model of Reading proposes that phonology, orthography, and semantics are crucial to understand word reading and reading disability (RD). Morphology has been added as a binding agent to this model. However, it is unclear how these variables relate to word reading in children with attention deficit/hyperactivity disorder (ADHD) or comorbid ADHD and RD (ADHD+RD). This study examined the performance of Chinese children with RD, ADHD, or ADHD+RD in phonology, orthography, semantics, and morphology, and investigated whether morphology made an additional contribution beyond the other skills in explaining word reading fluency. Participants were 151 Grade 1 to 3 Chinese students: RD (n = 31), ADHD (n = 43), ADHD+RD (n = 27), and typically developing controls (TD, n = 50). Results indicated that children with ADHD+RD (a) showed similar performance to RD and ADHD in tone awareness, orthographic legality, and homophone morpheme awareness; (b) had similar performance to RD but worse than ADHD in phonology, semantics, and morpheme production; and (c) had more severe deficits than RD and ADHD in orthographic reversal, morpheme identification, and homograph awareness. Morphology significantly predicted word reading fluency beyond the other skills, and its predictive effect was more salient for ADHD+RD, ADHD, and TD. The findings provide evidence of both shared and additive effects of RD and ADHD. Morphology may be an important diagnostic factor in identifying Chinese reading and behavioral deficit groups and a worthwhile target for intervention.

Reading anxiety modulates the functional connectivity of the reading-related network during adult reading

Researchers have studied cognitive and linguistic skills in predicting reading abilities, but the impact of affective factors such as anxiety on reading at the neurobiological level is not well understood. Here, we used functional magnetic resonance imaging to investigate the neural correlates of reading anxiety in adult readers performing a semantic judgment task. The results showed that reading anxiety was significantly correlated with response time but not with accuracy. Neurobiologically, functional connectivity strength rather than activation level of semantic-related areas significantly predicted reading anxiety. Activation of regions (i.e., the right putamen and right precentral gyrus) external to the semantic-related areas positively correlated with reading anxiety levels. These findings suggest that reading anxiety influences adult reading by modulating functional connections of semantic-related areas and brain activation of semantic-unrelated areas. This study provides insights into the neural mechanisms underlying reading anxiety experienced by adult readers.

Examination of common and unique brain regions for atypical reading and math: a meta-analysis

The purpose of this study is to identify consistencies across functional neuroimaging studies regarding common and unique brain regions/networks for individuals with reading difficulties (RD) and math difficulties (MD) compared to typically developing (TD) individuals. A systematic search of the literature, utilizing multiple databases, yielded 116 functional magnetic resonance imaging and positron emission tomography studies that met the criteria. Coordinates that directly compared TD with either RD or MD were entered into GingerALE (Brainmap.org). An activation likelihood estimate (ALE) meta-analysis was conducted to examine common and unique brain regions for RD and MD. Overall, more studies examined RD (n = 96) than MD (n = 20). Across studies, overactivation for reading and math occurred in the right insula and inferior frontal gyrus for atypically developing (AD) > TD comparisons, albeit in slightly different areas of these regions; however, inherent threshold variability across imaging studies could diminish overlying regions. For TD > AD comparisons, there were no similar or overlapping brain regions. Results indicate there were domain-specific differences for RD and MD; however, there were some similarities in the ancillary recruitment of executive functioning skills. Theoretical and practical implications for researchers and educators are discussed.

A sculpting effect of reading on later representational quality of phonology revealed by multi-voxel pattern analysis in young children

Using univariate analysis, a previous study by Wang et al. (2020) found a scaffolding effect of earlier phonological representation in superior temporal gyrus (STG) on later reading skill but failed to observe a sculpting effect of earlier reading on later phonological representation. The current study applied multi-voxel pattern analysis (MVPA) to examine if both scaffolding and sculpting effects were present in young children. We found that better initial reading skill predicted higher decoding coefficient of brain activity patterns for phonological representations in STG. This sculpting effect was present only for decoding small grain sizes (phonemes) and in younger children (6- to 7.5-year-olds), as we did not find any effects for large grain sizes (rhymes) or older children (7.5- to 9.5-year-olds). Although a scaffolding effect was not observed, the current study provides the first neural evidence of how earlier reading sculpts later phonological awareness in beginning readers.

Distinct neural correlates of poor decoding and poor comprehension in children with reading disability

Reading disability (RD) can manifest itself as a word decoding problem or a reading comprehension problem. In the current study, we identified 3 subtypes of RD: poor decoders (PD), poor comprehenders (PC), and poor-in-both (PB). We found that PD had greater deficits in meta-linguistic skills such as phonological awareness, orthographic skills, and morphological skills than PC, whereas PC had greater deficits in listening comprehension than PD. In the brain, we also found different patterns of deficits during an auditory rhyming judgment task using functional magnetic resonance imaging. PD showed less activation than PC and age controls in the left dorsal inferior frontal gyrus (IFG) and pre-supplementary motor area (SMA), brain activation of which was correlated with phonological awareness and working memory. In contrast, PC showed less activation in the left fusiform gyrus than PD and age controls, which was correlated with reading comprehension fluency and morphological skill. Last, PB showed both PD's and PC's deficits, as well as additional deficits in the bilateral lingual gyri. Our findings contribute to revealing different neural signatures of poor decoding and poor comprehension, which are distinct disorders but co-occur very often. These findings implicate possibility and necessity of precise diagnosis and individualized intervention.

Is learning a logographic script easier than reading an alphabetic script for German children with dyslexia?

PURPOSE

Developmental dyslexia in alphabetic languages (DD) is characterized by a phonological deficit. Since logographic scripts rely predominantly on visual and morphological processing, reading performance in DD can be assumed to be less impaired when reading logographic scripts.

METHODS

40 German-speaking children (18 with DD, 22 not reading-impaired-group C; 9-11 years) received Chinese lessons. Eye movements (EM) were recorded during naming single alphabetic words, pictures (confrontational) and Chinese characters to be named in German and Chinese. The main outcome variables were: Articulation latency, numbers and durations of fixations. Quality of life (QoL) was assessed by questionnaires.

RESULTS

While reading alphabetic words, articulation latencies and numbers of fixations were significantly higher for group DD than for group C (AL-DD = 1.13, AL-C = 0.84, p< .001; FN-DD = 3.50; FN-C = 2.00, p< .001). For naming pictures and Chinese characters in German and in Chinese, no significant group differences were found for any of the EM variables. The percentage of correct answers was high for German naming (DD = 86.67%, C = 95.24%; p = .015) and lower for Chinese naming in both groups, but significantly lower in group DD, especially for Chinese naming (DD = 56.67%, C: 83.77%; p = .003). QoL differed between groups from the children's perspective only at posttest. Parents of group DD perceived their children`s QoL to be lower compared with parents of group C at pre- and posttest.

CONCLUSIONS

Children with dyslexia performed as well as group C during naming Chinese characters in German and in Chinese regarding their EM variables, presumably because they processed Chinese characters by the visuo-spatial pathway with direct access to the semantic system. However, the significantly lower percentage of correct answers especially during Chinese naming showed that group DD had more difficulties naming Chinese characters than group C, which could be attributed to their phonological deficit, among other factors.

TRIAL REGISTRATION

German clinical trials register (DRKS00015697).

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.

Modulation of auditory temporal processing, speech in noise perception, auditory-verbal memory, and reading efficiency by anodal tDCS in children with dyslexia

Dyslexia is a neurodevelopmental disorder that is prevalent in children. It is estimated that 30-50% of individuals diagnosed with dyslexia also manifest an auditory perceptual deficit characteristic of auditory processing disorder (APD). Some studies suggest that defects in basic auditory processing can lead to phonological defects as the most prominent cause of dyslexia. Thus, in some cases, there may be interrelationships between dyslexia and some of the aspects of central auditory processing. In recent years, transcranial direct current stimulation (tDCS) has been used as a safe method for the modulation of central auditory processing aspects in healthy adults and reading skills in children with dyslexia. Therefore, the objectives of our study were to investigate the effect of tDCS on the modulation of different aspects of central auditory processing, aspects of reading, and the relationship between these two domains in dyslexic children with APD. A within-subjects design was employed to investigate the effect of two electrode arrays (the anode on the left STG (AC)/cathode on the right shoulder and anode on the left STG/cathode on the right STG) on auditory temporal processing; speech-in-noise perception, short-term auditory memory; and high-frequency word, low-frequency word, pseudoword, and text reading. The results of this clinical trial showed the modulation of the studied variables in central auditory processing and the accuracy and speed of reading variables compared to the control and sham statuses in both electrode arrays. Our results also showed that the improvement of the accuracy and speed of text reading, as well as the accuracy of pseudoword reading were related to the improvement of speech in noise perception and temporal processing. The results of this research can be effective in clarifying the basis of the neurobiology of dyslexia and, in particular, the hypothesis of the role of basic auditory processing and subsequently the role of the auditory cortex in dyslexia. These results might provide a framework to facilitate behavioral rehabilitation in dyslexic children with APD.

Extraction of discriminative features from EEG signals of dyslexic children; before and after the treatment

Dyslexia is a neurological disorder manifested as difficulty reading and writing. It can occur despite adequate instruction, intelligence, and intact sensory abilities. Different electroencephalogram (EEG) patterns have been demonstrated between dyslexic and healthy subjects in previous studies. This study focuses on the difference between patients before and after treatment. The main goal is to identify the subset of features that adequately discriminate subjects before and after a specific treatment plan. The treatment consists of Transcranial Direct Current Stimulation (tDCS) and occupational therapy using the BrainWare SAFARI software. The EEG signals of sixteen dyslexic children were recorded during the eyes-closed resting state before and after treatment. The preprocessing step was followed by the extraction of a wide range of features to investigate the differences related to the treatment. An optimal subset of features extracted from recorded EEG signals was determined using Principal Component Analysis (PCA) in conjunction with the Sequential Floating Forward Selection (SFFS) algorithm. The results showed that treatment leads to significant changes in EEG features like spectral and phase-related EEG features, in various regions. It has been demonstrated that the extracted subset of discriminative features can be useful for classification applications in treatment assessment. The most discriminative subset of features could classify the data with an accuracy of 92% with SVM classifier. The above result confirms the efficacy of the treatment plans in improving dyslexic children's cognitive skills.

The Brain Connectome for Chinese Reading

Chinese, as a logographic language, fundamentally differs from alphabetic languages like English. Previous neuroimaging studies have mainly focused on alphabetic languages, while the exploration of Chinese reading is still an emerging and fast-growing research field. Recently, a growing number of neuroimaging studies have explored the neural circuit of Chinese reading. Here, we summarize previous research on Chinese reading from a connectomic perspective. Converging evidence indicates that the left middle frontal gyrus is a specialized hub region that connects the ventral with dorsal pathways for Chinese reading. Notably, the orthography-to-phonology and orthography-to-semantics mapping, mainly processed in the ventral pathway, are more specific during Chinese reading. Besides, in addition to the left-lateralized language-related regions, reading pathways in the right hemisphere also play an important role in Chinese reading. Throughout, we comprehensively review prior findings and emphasize several challenging issues to be explored in future work.

The Functional Neuroanatomy of Reading Intervention

The present article reviews the literature on the brain mechanisms underlying reading improvements following behavioral intervention for reading disability. This includes evidence of neuroplasticity concerning functional brain activation, brain structure, and brain connectivity related to reading intervention. Consequently, the functional neuroanatomy of reading intervention is compared to the existing literature on neurocognitive models and brain abnormalities associated with reading disability. A particular focus is on the left hemisphere reading network including left occipito-temporal, temporo-parietal, and inferior frontal language regions. In addition, potential normalization/compensation mechanisms involving right hemisphere cortical regions, as well as bilateral sub-cortical and cerebellar regions are taken into account. The comparison of the brain systems associated with reading intervention and the brain systems associated with reading disability enhances our understanding of the neurobiological basis of typical and atypical reading development. All in all, however, there is a lack of sufficient evidence regarding rehabilitative brain mechanisms in reading disability, which we discuss in this review.

Comparative research on neural dysfunction in children with dyslexia under different writing systems: A meta-analysis study

Developmental dyslexia is a special learning disorder which is prevalent in all languages. A central question in dyslexia is whether the neural mechanism of their defects is universal or distinct in different writing systems. Using meta-analytic approach, we created meta-images using activation abnormalities in Chinese and alphabetic children with dyslexia to find convergence and divergence under different writing systems. The results revealed that dyslexic children have a universal attention-related dysfunction with hypoactivation in the left inferior frontal cortex (IFC) and the anterior cingulate cortex (ACC) under different writing systems, in spite of differences of degree and spatial extent in those regions. Alphabetic dyslexic children additionally showed hypoactivation in the left occipito-temporo-parietal regions. Chinese dyslexic children showed specific hyperactivation in the right postcentral gyrus, the left rectus, and the right middle temporal gyrus. The present meta-analysis for the first time showed both shared and distinct abnormalities in children with dyslexia under Chinese and alphabetic writing systems.

Influence of assistive technology applications on dyslexic students: The case of Saudi Arabia during the COVID-19 pandemic

In Saudi Arabia, the COVID-19 pandemic forced students with dyslexia to complete their learning through online applications, like their peers without dyslexia. This study explores the influence of assistive technology (AT) on improving the visual perception (VP) and phonological processing (PhP) abilities of students with dyslexia. Three learning applications were used (Google Classroom, Zoom, and Quizlet) as AT platforms. A quantitative approach was adopted based on a quasi-experimental design. Single-subject experimental methods were used to examine the influence of AT on improving students' VP, PhP, and frequency of access (FA). Fourteen students with dyslexia who were selected as participants through purposeful sampling were divided into two experimental groups based on gender. The results showed that AT influenced the VP, PhP, and FA in both experimental groups. Girls scored higher than boys in VP, PhP, and FA, and a positive correlation was found between VP and PhP with AT applications among girls and boys. A simple linear regression analysis showed that a significant and positive relationship exists between FA and the VP and PhP abilities of students with dyslexia through AT applications.

Improving Functional Connectivity in Developmental Dyslexia through Combined Neurofeedback and Visual Training

This study examined the effects of combined neurofeedback (NF) and visual training (VT) on children with developmental dyslexia (DD). Although NF is the first noninvasive approach to support neurological disorders, the mechanisms of its effects on the brain functional connectivity are still unclear. A key question is whether the functional connectivities of the EEG frequency networks change after the combined NF–VT training of DD children (postD). NF sessions of voluntary α/θ rhythm control were applied in a low-spatial-frequency (LSF) illusion contrast discrimination, which provides feedback with visual cues to improve the brain signals and cognitive abilities in DD children. The measures of connectivity, which are defined by small-world propensity, were sensitive to the properties of the brain electrical oscillations in the quantitative EEG-NF training. In the high-contrast LSF illusion, the z-NF reduced the α/θ scores in the frontal areas, and in the right ventral temporal, occipital–temporal, and middle occipital areas in the postD (vs. the preD) because of their suppression in the local hub θ-network and the altered global characteristics of the functional θ-frequency network. In the low-contrast condition, the z-NF stimulated increases in the α/θ scores, which induced hubs in the left-side α-frequency network of the postD, and changes in the global characteristics of the functional α-frequency network. Because of the anterior, superior, and middle temporal deficits affecting the ventral and occipital–temporal pathways, the z-NF–VT compensated for the more ventral brain regions, mainly in the left hemispheres of the postD group in the low-contrast LSF illusion. Compared to pretraining, the NF–VT increased the segregation of the α, β (low-contrast), and θ networks (high-contrast), as well as the γ2-network integration (both contrasts) after the termination of the training of the children with developmental dyslexia. The remediation compensated more for the dorsal (prefrontal, premotor, occipital–parietal connectivities) dysfunction of the θ network in the developmental dyslexia in the high-contrast LSF illusion. Our findings provide neurobehavioral evidence for the exquisite brain functional plasticity and direct effect of NF–VT on cognitive disabilities in DD children.

Atypical Relationships Between Neurofunctional Features of Print-Sound Integration and Reading Abilities in Chinese Children With Dyslexia

Conquering print-sound mappings (e.g., grapheme-phoneme correspondence rules) is vital for developing fluent reading skills. In neuroimaging research, this ability can be indexed by activation differences between audiovisual congruent against incongruent conditions in brain areas such as the left superior temporal cortex. In line with it, individuals with dyslexia have difficulty in tasks requiring print-sound processing, accompanied by a reduced neural integration. However, existing evidence is almost restricted to alphabetic languages. Whether and how multisensory processing of print and sound is impaired in Chinese dyslexia remains underexplored. In this study, we applied a passive audiovisual integration paradigm with functional magnetic resonance imaging to investigate the possible dysfunctions in processing character-sound (opaque; semantics can be automatically accessed) and pinyin-sound associations (transparent; no particular meaning can be confirmed) in Chinese dyslexic children. Unexpectedly, the dyslexic group did not show reduced neural integration compared with typically developing readers in either character or pinyin experiment. However, the results revealed atypical correlations between neural integration and different reading abilities in dyslexia. Specifically, while the neural integration in the left inferior frontal cortex in processing character-sound pairs correlated with silent reading comprehension in both children with and without dyslexia, it was associated with morphological awareness (semantic-related) in controls but with rapid naming (phonological-related) in dyslexics. This result indicates Chinese dyslexic children may not use the same grapho-semantic processing strategy as their typical peers do. As for pinyin-sound processing, while a stronger neural integration in the direction of "congruent > incongruent" in the left occipito-temporal cortex and bilateral superior temporal cortices was associated with better oral reading fluency in the control group, an opposite pattern was found in dyslexia. This finding may reflect dyslexia's dysfunctional recruitment of the regions in grapho-phonological processing, which further impedes character learning.

Visual Explanation for Identification of the Brain Bases for Developmental Dyslexia on fMRI Data

Problem: Brain imaging studies of mental health and neurodevelopmental disorders have recently included machine learning approaches to identify patients based solely on their brain activation. The goal is to identify brain-related features that generalize from smaller samples of data to larger ones; in the case of neurodevelopmental disorders, finding these patterns can help understand differences in brain function and development that underpin early signs of risk for developmental dyslexia. The success of machine learning classification algorithms on neurofunctional data has been limited to typically homogeneous data sets of few dozens of participants. More recently, larger brain imaging data sets have allowed for deep learning techniques to classify brain states and clinical groups solely from neurofunctional features. Indeed, deep learning techniques can provide helpful tools for classification in healthcare applications, including classification of structural 3D brain images. The adoption of deep learning approaches allows for incremental improvements in classification performance of larger functional brain imaging data sets, but still lacks diagnostic insights about the underlying brain mechanisms associated with disorders; moreover, a related challenge involves providing more clinically-relevant explanations from the neural features that inform classification.

Methods: We target this challenge by leveraging two network visualization techniques in convolutional neural network layers responsible for learning high-level features. Using such techniques, we are able to provide meaningful images for expert-backed insights into the condition being classified. We address this challenge using a dataset that includes children diagnosed with developmental dyslexia, and typical reader children.

Results: Our results show accurate classification of developmental dyslexia (94.8%) from the brain imaging alone, while providing automatic visualizations of the features involved that match contemporary neuroscientific knowledge (brain regions involved in the reading process for the dyslexic reader group and brain regions associated with strategic control and attention processes for the typical reader group).

Conclusions: Our visual explanations of deep learning models turn the accurate yet opaque conclusions from the models into evidence to the condition being studied.

Convergent and divergent brain structural and functional abnormalities associated with developmental dyslexia

Brain abnormalities in the reading network have been repeatedly reported in individuals with developmental dyslexia (DD); however, it is still not totally understood where the structural and functional abnormalities are consistent/inconsistent across languages. In the current multimodal meta-analysis, we found convergent structural and functional alterations in the left superior temporal gyrus across languages, suggesting a neural signature of DD. We found greater reduction in grey matter volume and brain activation in the left inferior frontal gyrus in morpho-syllabic languages (e.g. Chinese) than in alphabetic languages, and greater reduction in brain activation in the left middle temporal gyrus and fusiform gyrus in alphabetic languages than in morpho-syllabic languages. These language differences are explained as consequences of being DD while learning a specific language. In addition, we also found brain regions that showed increased grey matter volume and brain activation, presumably suggesting compensations and brain regions that showed inconsistent alterations in brain structure and function. Our study provides important insights about the etiology of DD from a cross-linguistic perspective with considerations of consistency/inconsistency between structural and functional alterations.

Poor reading is characterized by a more connected network with wrong hubs

Using graph theory, we examined topological organization of the language network in Chinese children with poor reading during an auditory rhyming task and a visual spelling task, compared to reading-matched controls and age-matched controls. First, poor readers (PR) showed reduced clustering coefficient in the left inferior frontal gyrus (IFG) and higher nodal efficiency in the bilateral superior temporal gyri (STG) during the visual task, indicating a less functionally specialized cluster around the left IFG and stronger functional links between bilateral STGs and other regions. Furthermore, PR adopted additional right-hemispheric hubs in both tasks, which may explain increased global efficiency across both tasks and lower normalized characteristic shortest path length in the visual task for the PR. These results underscore deficits in the left IFG during visual word processing and conform previous findings about compensation in the right hemisphere in children with poor reading.

The brain basis of handwriting deficits in Chinese children with developmental dyslexia

Abundant behavioral studies have demonstrated high comorbidity of reading and handwriting difficulties in developmental dyslexia (DD), a neurological condition characterized by unexpectedly low reading ability despite adequate nonverbal intelligence and typical schooling. 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 DD. The present work used functional magnetic resonance imaging to examine brain activity during handwriting and reading tasks in Chinese dyslexic children (n = 18) and age-matched controls (n = 23). 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. Together, these findings suggest that handwriting deficits in DD 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.

Occurrence of reading and writing cognitive processes and perception visual skills in students with Visual Dyslexia

PURPOSE

to evaluate and classify visual dyslexic students, considering that developmental dyslexia subtypes are not differentiated in most diagnoses and that they affect a generalized approach.

METHODS

Cross-sectional, observational, analytical study composed of 80 students, divided into two groups, GA (dyslexics) and GB (without complaints of learning difficulties) using PROLEC (proof of assessment of reading processes), TVPS - 3 (Visual Test of Perceptual Skills) and TPMBO (Bruininks-Oseretsky Motor Proficiency Test) - subtests 7 and 8.

RESULTS

Comparing the groups, the students of GA presented inferior performance in all the PROLEC tests and in the TVPS3 tests. The TPMBO tests of visuomotor coordination and manual dexterity tests were inferior. In a second stage, screening the visual dyslexics, 12 (30%) schoolchildren were found, who presented better performance in reading frequent words, when compared to the performance in reading infrequent words and pseudowords. In the visual perceptual skills (TVPS-3), they obtained values below 50%, except for the subscale constancy of form. The occurrences of exchanges in reading aloud were in confusion of letters, syllables or words with little difference in the way of writing, but different in the direction, the same students did not present exchanges or confusions between letters, which have the same point and manner of articulation, and whose sounds are acoustically close.

CONCLUSION

Thus, characterizing the dyslexia subtype is fundamental, because the application of therapeutic techniques will depend on the correct focus of the observed changes. Therefore, an accurate and multidisciplinary diagnosis is required.

Stroop interference in children with developmental dyslexia: An event-related potentials study

Previous studies have identified inhibitory deficits in dyslexic children, but we have little understanding of their neural mechanisms, especially for Chinese children with developmental dyslexia.We used a double-blind controlled trial to study the electroencephalogram responses of dyslexic and non-dyslexic children when performing the Stroop color-word test.Behavioral data showed differences in response time and accuracy between the 2 groups. In the event-related potentials (ERP) results, dyslexic children displayed larger P2 and P3b on congruent trials, while non-dyslexic children displayed larger P2 and P3b on incongruent trials, the 2 groups showed opposite brain activation patterns on the Stroop test.Dyslexic children have poor inhibitory function, and this poor inhibition may be related to their abnormal brain activation patterns.

Both frontal and temporal cortex exhibit phonological and semantic specialization during spoken language processing in 7- to 8-year-old children

A previous functional magnetic resonance imaging (fMRI) study by Weiss et al. (Weiss et al., Human Brain Mapping, 2018, 39, 4334–4348) examined brain specialization for phonological and semantic processing of spoken words in young children who were 5 to 6 years old and found evidence for specialization in the temporal but not the frontal lobe. According to a prominent neurocognitive model of language development (Skeide & Friederici, Nature Reviews Neuroscience, 2016, 17, 323–332), the frontal lobe matures later than the temporal lobe. Thus, the current study aimed to examine if brain specialization in the frontal lobe can be observed in a slightly older cohort of children aged 7 to 8 years old using the same experimental and analytical approach as in Weiss et al. (Weiss et al., Human Brain Mapping, 2018, 39, 4334–4348). One hundred and ten typically developing children were recruited and were asked to perform a sound judgment task, tapping into phonological processing, and a meaning judgment task, tapping into semantic processing, while in the MRI scanner. Direct task comparisons showed that these children exhibited language specialization in both the temporal and the frontal lobes, with the left posterior dorsal inferior frontal gyrus (IFG) showing greater activation for the sound than the meaning judgment task, and the left anterior ventral IFG and the left posterior middle temporal gyrus (MTG) showing greater activation for the meaning than the sound judgment task. These findings demonstrate that 7‐ to 8‐year‐old children have already begun to develop a language‐related specialization in the frontal lobe, suggesting that early elementary schoolers rely on both specialized linguistic manipulation and representation mechanisms to perform language tasks.

A hierarchical deficit model of reading disability: Evidence from dynamic causal modelling analysis

Deficits have been documented in visuo-orthographic processing as well as phonological retrieval/manipulation during visual word reading in individuals with reading disability (RD); however, the relationship between these deficits remains unclear. Previously, we found that during word reading, visuo-orthographic deficit appears to be a neural signature of RD, but deficits in phonological retrieval/manipulation appears to be a consequence of being RD (Cao et al., 2020). Therefore, in the current study, we directly tested the hypothesis that during visual word reading, deficit in phonological retrieval/manipulation may result from weakened input from visuo-orthographic regions, and that this relationship tends to be universal across languages. We conducted a dynamic causal modelling analysis of fMRI data from Chinese-English bilingual children (9-11 years, N = 78) with or without RD during a visual word rhyming judgment task. We found a weaker connection from the left inferior temporal gyrus (ITG) to the left dorsal inferior frontal gyrus (dIFG) in children with RD and reading controls than the connection found in age controls for both Chinese and English. This finding suggests that the phonological deficit at the dIFG may result from weak input from the visuo-orthographic region and this connection appears to be responsive to reading level rather than RD, because the reading-control children were similar to children with RD. We also found that the left ITG was selectively connected with language-specific regions (i.e., the left inferior parietal lobe (IPL) for Chinese and the left ventral inferior frontal gyrus (vIFG) for English) depending on the language being processed; however, this language selectivity was reduced in children with RD, suggesting that decreased language specialization is associated with RD. Using a double control design, our study suggests that during reading, the visuo-orthographic deficit of RD constrains the development of the connection from orthography to phonology and to other language-specific processing due to distorted quantity and quality of reading.

Disrupted Subcortical-Cortical Connections in a Phonological but Not Semantic Task in Chinese Children With Dyslexia

Reading disability has been considered as a disconnection syndrome. Recently, an increasing number of studies have emphasized the role of subcortical regions in reading. However, the majority of research on reading disability has focused on the connections amongst brain regions within the classic cortical reading network. Here, we used graph theoretical analysis to investigate whether subcortical regions serve as hubs (regions highly connected with other brain regions) during reading both in Chinese children with reading disability (N = 15, age ranging from 11.03 to 13.08 years) and in age-matched typically developing children (N = 16, age ranging from 11.17 to 12.75 years) using a visual rhyming judgment task and a visual meaning judgment task. We found that the bilateral thalami were the unique hubs for typically developing children across both tasks. Additionally, subcortical regions (right putamen, left pallidum) were also unique hubs for typically developing children but only in the rhyming task. Among these subcortical hub regions, the left pallidum showed reduced connectivity with inferior frontal regions in the rhyming judgment but not semantic task in reading disabled compared with typically developing children. These results suggest that subcortical-cortical disconnection, which may be particularly relevant to the phonological and phonology-related learning process, may be associated with Chinese reading disability.

Functional connectivity alterations associated with literacy difficulties in early readers

The link between literacy difficulties and brain alterations has been described in depth. Resting-state fMRI (rs-fMRI) has been successfully applied to the study of intrinsic functional connectivity (iFc) both in dyslexia and typically developing children. Most related studies have focused on the stages from late childhood into adulthood using a seed to voxel approach. Our study analyzes iFc in an early childhood sample using the multivariate pattern analysis. This facilitates a hypothesis-free analysis and the possible identification of abnormal functional connectivity patterns at a whole brain level. Thirty-four children with literacy difficulties (LD) (7.1 ± 0.69 yr.) and 30 typically developing children (TD) (7.43 ± 0.52 yr.) were selected. Functional brain connectivity was measured using an rs-fMRI acquisition. The LD group showed a higher iFc between the right middle frontal gyrus (rMFG) and the default mode network (DMN) regions, and a lower iFc between the rMFG and both the bilateral insular cortex and the supramarginal gyrus. These results are interpreted as a DMN on/off routine malfunction in the LD group, which suggests an alteration of the task control network regulating DMN activity. In the LD group, the posterior cingulate cortex also showed a lower iFc with both the middle temporal poles and the fusiform gyrus. This could be interpreted as a failure in the integration of information between brain regions that facilitate reading. Our results show that children with literacy difficulties have an altered functional connectivity in their reading and attentional networks at the beginning of the literacy acquisition. Future studies should evaluate whether or not these alterations could indicate a risk of developing dyslexia.

Developmental dyslexia: A new look at clinical features and brain mechanisms

Developmental dyslexia is the commonest "specific learning disorder" (DSM-5) or "developmental learning disorder with impairment in reading" (ICD-11). This impairment in reading acquisition is related to a defect in the installation of cognitive precursors necessary to master the grapheme-phoneme conversion. Its origin is largely genetic, but many environmental factors seem capable of modulating symptom intensity. Three types of presentation, roughly equal in occurrence, are useful to distinguish according to the associated disorders (language, attentional, and/or motor coordination), thus suggesting, at least in part, potentially different mechanisms at their origin. In adolescence and adulthood the clinical presentation tends to bear a more uniform pattern, covering a large range of severity depending on each person's ability to compensate for their deficit. Research has demonstrated dysfunction of specific brain areas during reading-related tasks (using fMRI), essentially in the left cerebral hemisphere, but also atypical patterns of connectivity (using diffusion imaging), further supplemented by functional connectivity studies at rest. The current therapeutic recommendations emphasize the need for multidisciplinary care, giving priority, depending on the clinical form, to the language, psychomotor, or neuropsychologic aspects of rehabilitation. Various training methods whose effectiveness has been scientifically tested are reviewed, emphasizing those exploiting the hypothesis of a lack of intermodal connectivity between separate cognitive systems.

Functional parcellation of the right cerebellar lobule VI in children with normal or impaired reading

Neuroimaging studies have reported that the right cerebellar lobule VI is engaged in reading, but its role is unclear. The goal of our study was to identify functionally-dissociable subregions in the right lobule VI and how these subregions contribute to reading in children with normal or impaired reading. In Experiment I, typically developing children performed an orthographic task and a phonological task during functional magnetic resonance imaging (fMRI). We classified the voxels in the right lobule VI into seven zones based on the patterns of functional connectivity with the cerebrum across both tasks. In Experiment II, we compared the brain activation and cerebro-cerebellar connectivities of each subregion between children readers with different reading levels. We did not find significant group differences in cerebellar activation. However, we found that impaired readers had considerably higher functional connectivity between R1 and the right angular gyrus and the right precuneus compared to the control group in the phonological task. These findings show that the right cerebellar lobule VI is functionally parceled and its subregions might be differentially connected with the cerebrum between children with normal reading abilities and those with impaired reading.

Reading Disability in Chinese Children Learning English as an L2

To examine whether there are common or specific deficits of reading disability (RD) in first (L1) and second languages (L2), Chinese children (9-11 years, N = 76) with or without RD who learn English as an L2 were studied during a visual word rhyming judgment task. Evidence was found for common deficits in L1 and L2 in visuo-orthographic processes in left inferior temporal gyrus and left precuneus, as well as in phonological processes in left dorsal inferior frontal gyrus as children with RD showed less activation than controls in both languages. Furthermore, the visuo-orthographic deficit appears to be a RD effect, whereas the phonological deficit appears to be a reading/performance effect. Some weak evidence for language specific effects was also found.

The Functional Neuroanatomy of Developmental Dyslexia Across Languages and Writing Systems

The present article reviews the literature on the functional neuroanatomy of developmental dyslexia across languages and writing systems. This includes comparisons of alphabetic languages differing in orthographic depth as well as comparisons across alphabetic, syllabic, and logographic writing systems. It provides a synthesis of the evidence for both universal and language-specific effects on dyslexic functional brain activation abnormalities during reading and reading-related tasks. Specifically, universal reading-related underactivation of dyslexic readers relative to typical readers is identified in core regions of the left hemisphere reading network including the occipito-temporal, temporo-parietal, and inferior frontal cortex. Orthography-specific dyslexic brain abnormalities are mainly related to the degree and spatial extent of under- and overactivation clusters. In addition, dyslexic structural gray matter abnormalities across languages and writing systems are analyzed. The neuroimaging findings are linked to the universal and orthography-dependent behavioral manifestations of developmental dyslexia. Finally, the present article provides insights into potential compensatory mechanisms that may support remediation across languages and writing systems.

Whole-Brain Functional Networks for Phonological and Orthographic Processing in Chinese Good and Poor Readers

The neural basis of dyslexia in different languages remains unresolved, and it is unclear whether the phonological deficit as the core deficit of dyslexia is language-specific or universal. The current functional magnetic resonance imaging (fMRI) study using whole-brain data-driven network analyses investigated the neural mechanisms for phonological and orthographic processing in Chinese children with good and poor reading ability. Sixteen good readers and 16 poor readers were requested to make homophone judgments (phonological processing) and component judgments (visual-orthographic processing) of presented Chinese characters. Poor readers displayed worse performance than the good readers in phonological processing, but not in orthographic processing. Whole-brain activation analyses showed compensatory activations in the poor readers during phonological processing and automatic phonological production activation in the good readers during orthographic processing. Significant group differences in the topological properties of their brain networks were found only in orthographic processing. Analyses of nodal degree centrality and betweenness centrality revealed significant group differences in both phonological and orthographic processing. The present study supports the phonological core deficit hypothesis of reading difficulty in Chinese. It also suggests that Chinese good and poor readers might recruit different strategies and neural mechanisms for orthographic processing.

Improving sentence reading performance in Chinese children with developmental dyslexia by training based on visual attention span

Deficits in the visual attention span (VAS) are thought to hamper reading performance in dyslexic individuals. However, the causal relationship between VAS deficits and reading disability remains unclear. The present study attempts to address this issue by using a VAS-based intervention to explore the possible influence of VAS on reading processes in Chinese children with dyslexia. Given the influence of the heterogeneity of dyslexia on intervention effects, VAS-impaired dyslexic and VAS-intact dyslexic individuals were separately trained. Therefore, there were five groups of participants in this study, including 10 trained dyslexic individuals with VAS deficits and 10 untrained dyslexic individuals with VAS dysfunction as the baseline reference, 10 trained and 10 untrained dyslexic individuals with an intact VAS, and fourteen age-matched normal readers for reference of normal level. All participants completed reading measures and a visual 1-back task, reflecting VAS capacity with non-verbal stimuli and non-verbal responses, before and after VAS-based training. VAS-based training tasks included a length estimation task regarding the bottom-up attention, visual search and digit cancelling tasks targeting top-down attentional modulation, and visual tracking tasks to train eye-movement control. The results showed that visual training only helped improve VAS skills in VAS-impaired dyslexic individuals receiving training. Meanwhile, their silent sentence reading accuracy improved after training, and there was a significant relationship between training improvements in VAS function and reading performance. The current findings suggest that VAS-based training has a far-transfer effect on linguistic level (i.e., fluent reading). These findings suggest the possibility that VAS-related training may help children with dyslexia improve their reading skills.

Brain Mechanisms Underlying Visuo-Orthographic Deficits in Children With Developmental Dyslexia

Multiple hypotheses have been proposed to explain the reading difficulty caused by developmental dyslexia (DD). The current study examined visuo-orthographic processing in children with dyslexia to determine whether orthographic deficits are explainable based solely on visual deficits. To identify orthographic-specific, visual perception-specific, and overlapping deficits, we included two tasks (lexical and perceptual) in three Chinese subject groups: children with DD, age-matched controls (AC), and reading matched controls (RC) using functional magnetic resonance imaging (fMRI). We found that the left precuneus showed decreased activation across both tasks for the DD group compared to the two control groups, thus reflecting visual processing deficits in children with DD, which also affects orthographic processing. Furthermore, we found that the functional connectivity between left middle occipital gyrus (LMOG) and left inferior frontal gyrus (IFG) was decreased in the DD group compared to AC and RC for only the lexical task. This suggests a weaker association between orthography and phonology for children with DD. In addition, the children with DD showed decreased functional connectivity between the LMOG and right parahippocampal gyrus for only the visual perceptual task, thereby indicating a weaker association between visual regions for DD during visual symbol processing. Taken together, our findings suggest that the observed orthographic processing deficit in DD might be driven by both a basic visual deficit, and a linguistic deficit.

Neural Correlates of Orthographic Access in Mandarin Chinese Writing: An fMRI Study of the Word-Frequency Effect

Writing is an essential tool for human communication and involves multiple linguistic, cognitive, and motor processes. Chinese, a logographic writing system, differs remarkably from the writing systems of alphabetic languages. The neural substrates of Chinese writing are largely unknown. Using functional magnetic resonance imaging (fMRI) in a copying task, this study probed the neural underpinnings of orthographic access during Mandarin Chinese writing by employing the word-frequency effect. The results showed that writing low-frequency characters evoked greater activation in the bilateral superior/middle/inferior frontal gyrus, superior/inferior parietal lobule, and fusiform gyrus than writing high-frequency characters. Moreover, psychophysiological interaction (PPI) analysis demonstrated that the word-frequency effect modulated functional connectivity within the frontal-occipital networks and the parietal-occipital networks. Together, these findings illustrate the neural correlates of orthographic access for Mandarin Chinese writing, shedding new light on the cognitive architecture of writing across various writing systems.

Impact of Transcranial Direct Current Stimulation on Reading Skills of Children and Adolescents With Dyslexia

Introduction:

Rehabilitation techniques have been used to facilitate reading acquisition in dyslexia. However, many individuals continue to present academic impairment throughout life. New intervention strategies are necessary to further help this population.

Objectives:

Assess the impact of transcranial direct current stimulation on reading skills in children and adolescents with dyslexia.

Methods:

The study was conducted with one-group pretest–posttest. Participants received 2 mA transcranial direct current stimulation during 30 minutes for 5 consecutive days. Reading performance was measured by a group of tasks (identification and reading of letters, syllables, words, nonwords, and text).

Results:

A significant increase in the number of correct answers for nonwords and text tasks was observed after transcranial direct current stimulation (P = .035 and P = .012, respectively).

Conclusion:

The transcranial direct current stimulation seems to be a promising tool for the treatment of reading problems in dyslexia. Future studies are necessary to confirm the effects of transcranial direct current stimulation and to establish optimal intervention protocol in this population.

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.

[Verbal and visual-spatial memory in Chinese children with developmental dyslexia]

OBJECTIVE

To explore the abilities of verbal and visual-spatial memory in Chinese children with developmental dyslexia.

METHODS

Thirty-two children with developmental dyslexia (aged 8-12 years) and thirty-nine age- and gender-matched normal children were involved in the study. Their verbal short-term and verbal working memories were measured using the digit ordering and the digit span tests, respectively. Their visual-spatial short-term and visual-spatial working memories were examined using the forward and backward block-tapping tests, respectively.

RESULTS

The DD children scored lower in the digit ordering and the digit span tests than the control children (P&lt;0.05). The scores for the forward and backward block-tapping tests did not vary between the two groups (P&gt;0.05).

CONCLUSIONS

The children with DD have the deficits in both verbal short-term memory and verbal working memory.

Neurobiological bases of reading disorder Part I: Etiological investigations

While many studies have focused on identifying the neural and behavioral characteristics of decoding-based reading disorder (RD, aka developmental dyslexia), the etiology of RD remains largely unknown and understudied. Because the brain plays an intermediate role between genetic factors and behavioral outcomes, it is promising to address causality from a neural perspective. In the current, Part I of the two-part review, we discuss neuroimaging approaches to addressing the causality issue and review the results of studies that have employed these approaches. We assume that if a neural signature were associated with RD etiology, it would (a) manifest across comparisons in different languages, (b) be experience independent and appear in comparisons between RD and reading-matched controls, (c) be present both pre- and post-intervention, (d) be found in at-risk, pre-reading children and (e) be associated with genetic risk. We discuss each of these five characteristics in turn and summarize the studies that have examined each of them. The available literature provides evidence that anomalies in left temporo-parietal cortex, and possibly occipito-temporal cortex, may be closely related to the etiology of RD. Improved understanding of the etiology of RD can help improve the accuracy of early detection and enable targeted intervention of cognitive processes that are amenable to change, leading to improved outcomes in at-risk or affected populations.

Brain MRI data in Chinese dyslexic children performing an auditory rhyming judgment task

This article includes the description of data information from an auditory rhyming judgment task in Chinese children with developmental dyslexia, age-matched control children and reading-matched control children. You will find fMRI data information including experimental design, MRI protocol, and brain activation results from each of the three groups of subjects. Other results from the same study were published in Neuroimage (Cao, in press [1]).