Developmental Dyslexia Group Research Articles

Foveal crowding in children with developmental dyslexia.

Excessive crowding in the visual periphery has been demonstrated in children with developmental dyslexia (DD). However, less is known about crowding in the fovea, even though foveal crowding is at least equally important, as reading is mostly accomplished through foveal vision. Here we used a special set of digitstimuli (Pelli fonts) to measure foveal crowding in DD and DD + ADHD children, and compared it to that in TD (typically developing) and ADHD children. We also used the Chinese reading acuity charts (C-READ) to assess the maximum reading speed and reading acuity, along with tests to evaluate cognitive attributes including phonological awareness, rapid automatized naming, morphological awareness, and orthographic knowledge. The results indicate significantly stronger foveal crowding in the DD and DD + ADHD groups, as well as in the ADHD group, than in the TD group. Furthermore, the DD and DD + ADHD groups exhibited poorer maximum reading speed and reading acuity compared to the ADHD and TD groups.Within the two DD groups, theslower maximum reading speed and higher reading acuitycan be predicted bystronger foveal crowding. In addition, the DD and DD + ADHD groups performed the worst in four cognitive skills, with the DD group showing negative correlations between foveal crowding and performances across all these skills. Our findings thus move beyond previously well-documented peripheral crowding in dyslexia, and the easy administration of the Pelli-font-based crowding test may be useful for early diagnosis of developmental dyslexia in young children.

Spelling Development of Korean 1st Graders with and without Developmental Dyslexia

Objectives: This study examined the word writing abilities of Korean 1st graders with and without developmental dyslexia (DD) considering meaning accessibility and the structure of a Korean syllable. Methods: Fifteen typically developing children (TD) and fifteen children with developmental dyslexia were assigned word writing tasks in the first and second semesters of the first year. The word writing task contains ten words and ten non-words containing forty syllable-initial and syllable-medial graphemes, and twenty-two syllable-final graphemes. The analysis of the results was conducted in grapheme units, and the accuracy for each word/nonword and the error rate for each structure of a syllable was determined. Results: The DD group showed significant growth in both words/nonwords writing accuracy by the second semester, and the error rates of syllable-initial, syllable-medial, and syllable-final graphemes significantly decreased from the first to the second semester for the DD group. The TD group showed no significant difference in word/non-words writing, and there was no significant difference in error rates according to the structure of a syllable. Both the DD and TD groups showed higher error rates in final graphemes in both the first and second semesters. Conclusion: The word writing abilities of the DD group showed significant growth between the first and second semesters but still had difficulties, particularly in the final grapheme writing. The TD group developed word writing first, and nonword writing was still in development. But final grapheme writing was difficult even for TD group. Follow-up studies are needed to closely observe the developmental processes comparing with decoding level matched TD children.

Unraveling the complex interplay between statistical learning and working memory in Chinese children with and without dyslexia across different ages.

The relation between statistical learning and working memory in children with developmental dyslexia (DD) remains unclear. This study employed a distributional and a conditional statistical learning experiment and a working memory task to examine this relation in 651 Chinese 6- to 12-year-olds with and without DD (NDD = 199, 101 females; NwoDD = 452, 227 females; participated 2014-2019). Results showed working memory positively associated with recognizing high-predictable and familiar items in both groups, but negatively associated with recognizing unfamiliar items in the DD group only. These findings uncovered the complex interplay between statistical learning and working memory, demonstrating how different working memory abilities in children with and without DD relate to various statistical learning mechanisms at the item level.

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.

Altered effective connectivity on rapid automatized naming deficits in Chinese children with developmental dyslexia: An rs-fMRI study with Ganger causality analysis

Rapid Automatized Naming (RAN) is the core defect of developmental dyslexia (DD), requiring collaboration among brain areas to complete. However, it's still unclear which effective connectivity (EC) among brain areas are crucial for RAN deficits in Chinses children with DD. The current study aims to explore the EC among brain areas related to RAN deficits in Chinese children with DD. We recruited 36 Chinese children with DD and 64 typically developing (TD) children aged 8–12 to complete resting-state functional magnetic resonance imaging (rs-fMRI) scan. Granger causality analysis (GCA) was employed to analysis the EC among brain areas related to RAN, and to calculate the relationship between EC and RAN scores. Compared to TD group, the DD group exhibited significantly decreased EC from left precentral gyrus (PG) to right precuneus, left anterior cingulate and paracingulate gyrus (ACG), left calcarine and right angular, from left middle frontal gyrus (MFG) to left calcarine. Additionally, the DD group showed increased EC from right cuneus to left inferior frontal gyrus triangular part (IFGtri). The EC from left PG to left ACG was positively correlated with letters-RAN score. The results showed Chinese children with DD had both defect and compensatory mechanisms for their RAN deficits. The decreased EC output from left PG may be the core problem of the RAN deficits, which may influence the integration of visual-spatial information, attention, memory retrieval, and speech motor in speech production. The current study has important clinic implications for establishing intervention measures targeted brain.

Are Communication Skills, Emotion Regulation and Theory of Mind Skills Impaired in Adolescents with Developmental Dyslexia?

ABSTRACT This study investigates pragmatic language impairment, Theory of Mind (ToM), and emotion regulation in adolescents with Developmental Dyslexia(DD). The Social Responsiveness Scale-2(SRS) and Children’s Communication Checklist-2(CCC-2) scores were found to be statistically significantly higher in the DD group than in healthy controls. DD group had lower performance in ToM skills and they have more difficulties in emotion regulation. We also found that CCC-2 and ToM scores were significantly correlated in adolescents with DD. These results may be important in understanding the difficulties experienced in social functioning and interpersonal relationships in adolescents with DD.

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

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

Speech disfluencies in children with developmental dyslexia: How do they differ from typical development?

Disfluency is a multifactorial concept that can be linked to several of the language production levels, in both typical and atypical populations. In children, the language system is still developing and few studies have explored disfluency patterns. In typical development (TD), in particular, studies have shown discrepancies according to the language being considered. In neurodevelopmental disorders, such as developmental dyslexia (DD), it is still unclear whether the pattern of disfluency is similar to TD. To analyse the type of disfluency and their evolution in French children aged 8-12 years. Also to compare the pattern of disfluency in DD and TD, and to test whether disfluencies were correlated with reading difficulties. A total of 25 children with DD and 21 children with TD aged 8-12.6 years produced an autobiographical narrative. Seven types of disfluencies were coded: part-word repetitions; repetitions of monosyllabic words; other types of repetitions (words and phrases); filled pauses; revisions-substitutions; revisions-additions; and abandoned utterances. We compared the proportion of each disfluency in DD and TD. Spearman correlations were then performed between disfluencies, reading performance and age. The results showed that both DD and TD children mainly produced filled pauses, repetitions of monosyllabic words and substitutions. Both groups displayed a high rate of disfluency (> 10%). No correlations with age were found. Correlations with reading performance were significant in the TD group only. The study showed that DD is not characterized by a specific pattern of disfluency. Additionally, disfluency rates were similar in children aged 8-12 years. In contrast to other languages, the current study suggests that French-speaking children have a high rate of disfluency. The study also suggests that disfluency should be interpreted with caution in DD, given that TD children also have a high rate of disfluency. Therefore, it seems important to adapt the pathological threshold of disfluency to the language being spoken in order to avoid an overestimation of the prevalence of these deficits in French-speaking children. What is already known on this subject TD children produce a high rate of disfluency, which is also influenced by the language being spoken. No study looked at the effect of DD on disfluency production. Nonetheless, problems in reading comprehension and reduced reading experience may impact lexical development and speech fluency. What this paper adds to the existing knowledge In our study, both groups (French-speaking children) produced a substantial amount of disfluency as compared with other languages (> 10%). Additionally, the pattern of disfluency was similar in TD and DD (namely, filled pauses, prolongations repetitions of monosyllabic words and substitutions). In the DD group, disfluency production was not correlated with reading performance. What are the potential or actual clinical implications of this work? These results indicate that it is crucial to consider the language being spoken when examining disfluency in order to avoid an overestimation of language difficulties in some languages, such as in French. Moreover, the production of disfluencies in DD should not be considered as language dysfunction since the pattern of disfluency what quite similar in TD and DD, and did not correlate with their reading difficulties.

Atypical function of auditory sensory gating in children with developmental dyslexia: Investigating its relationship with cognitive abilities.

Impairments of auditory processing are among frequent findings in dyslexia. However, it is unclear how auditory signals are gated from brainstem to higher central processing stages in these individuals. The present study was done to investigate auditory sensory gating in children with developmental dyslexia (DD), and to determine whether sensory gating correlates with performance on behavioural tasks. Auditory sensory gating at P50, N1 and P2 waves was evaluated in two groups including 20 children with DD and 19 children with typical reading development (TRD). Behavioural tests were used to evaluate phonological working memory (PWM) and selective attention abilities. Sensory gating in children with DD was significantly less efficient than their peers at P50, N1 and P2 waves. Lower auditory evoked potential (AEP) amplitudes were found in the DD group. The children with TRD scored better in all the behavioural tests. Relationships were reported between sensory gating at P50, N1, P2 and behavioural performance in the two groups. Children with dyslexia had deficient sensory gating in comparison with controls. In addition, children with dyslexia experienced problems with PWM and selective attention tasks. The function of sensory gating was associated with attentional and PWM performances in this group.

Reduced Implicit but not Explicit Knowledge of Cross-Situational Statistical Learning in Developmental Dyslexia.

Although statistical learning (SL) has been studied extensively in developmental dyslexia (DD), less attention has been paid to other fundamental challenges in language acquisition, such as cross-situational word learning. Such investigation is important for determining whether and how SL processes are affected in DD at the word level. In this study, typically developed (TD) adults and young adults with DD were exposed to a set of trials that contained multiple spoken words and multiple pictures of individual objects, with no information about word-referent correspondences provided within a trial. Nonetheless, cross-trial statistical relations could be exploited to learn word-referent mappings. The degree of within-trial reference uncertainty and the novelty of to-be-learned objects (novel or familiar) were varied under different learning conditions. The results show that across all conditions, young adults with DD were significantly impaired in their ability to exploit cross-trial regularities in co-occurring visual-auditory streams to discover word-referent mappings. Observed impairments were most pronounced when within-trial reference uncertainty was the highest. Subjective measures of knowledge awareness revealed greater development of implicit but not explicit knowledge in the TD group than in the DD group. Together, these findings suggest that the SL deficit in DD affects fundamental language learning challenges at the word level and points to greater reliance on explicit processes due to impaired implicit associative learning among individuals with DD. Such a deficit is likely to influence spoken language acquisition, and in turn affect literacy skills, in people with DD.

Periodic and Aperiodic EEG Features as Potential Markers of Developmental Dyslexia.

Developmental Dyslexia (DD) is a neurobiological condition affecting the ability to read fluently and/or accurately. Analyzing resting-state electroencephalographic (EEG) activity in DD may provide a deeper characterization of the underlying pathophysiology and possible biomarkers. So far, studies investigating resting-state activity in DD provided limited evidence and did not consider the aperiodic component of the power spectrum. In the present study, adults with (n = 26) and without DD (n = 31) underwent a reading skills assessment and resting-state EEG to investigate potential alterations in aperiodic activity, their impact on the periodic counterpart and reading performance. In parieto-occipital channels, DD participants showed a significantly different aperiodic activity as indexed by a flatter and lower power spectrum. These aperiodic measures were significantly related to text reading time, suggesting a link with individual differences in reading difficulties. In the beta band, the DD group showed significantly decreased aperiodic-adjusted power compared to typical readers, which was significantly correlated to word reading accuracy. Overall, here we provide evidence showing alterations of the endogenous aperiodic activity in DD participants consistently with the increased neural noise hypothesis. In addition, we confirm alterations of endogenous beta rhythms, which are discussed in terms of their potential link with magnocellular-dorsal stream deficit.

Neural correlates of statistical learning in developmental dyslexia: An electroencephalography study

The human brain extracts statistical regularities from the surrounding environment in a process called statistical learning. Behavioural evidence suggests that developmental dyslexia affects statistical learning. However, surprisingly few studies have assessed how developmental dyslexia affects the neural processing underlying this type of learning. We used electroencephalography to explore the neural correlates of an important aspect of statistical learning – sensitivity to transitional probabilities – in individuals with developmental dyslexia. Adults diagnosed with developmental dyslexia (n = 17) and controls (n = 19) were exposed to a continuous stream of sound triplets. Every so often, a triplet ending had a low transitional probability given the triplet’s first two sounds (“statistical deviants”). Furthermore, every so often a triplet ending was presented from a deviant location (“acoustic deviants”). We examined mismatch negativity elicited by statistical deviants (sMMN), and MMN elicited by location deviants (i.e., acoustic changes). Acoustic deviants elicited a MMN which was larger in the control group than in the developmental dyslexia group. Statistical deviants elicited a small, yet significant, sMMN in the control group, but not in the developmental dyslexia group. However, the difference between the groups was not significant. Our findings indicate that the neural mechanisms underlying pre-attentive acoustic change detection and implicit statistical auditory learning are both affected in developmental dyslexia.

Developmental dyslexia, developmental coordination disorder and comorbidity discrimination using multimodal structural and functional neuroimaging

Developmental dyslexia (DD) and developmental coordination disorder (DCD) are two common neurodevelopmental disorders with a high co-occurrence rate. This led several authors to postulate that the two disorders share, at least partially, similar neural underpinning. However, even though several studies examined brain differences between typically developing (TD) children and children with either DD or DCD, no previous study directly compared DD, DCD and children with both disorders (COM) using neuroimaging. We acquired structural and resting-state functional MRI images of 136 children (TD = 42, DD = 45, DCD = 20, COM = 29). Difference between TD children and the other groups was assessed using univariate analysis of structural indexes including grey and white matter volumes and functional indexes quantifying activity (fraction of the amplitude of the low frequency fluctuations), local and global connectivity. Regional differences in structural and functional brain indexes were then used to train machine learning models to discriminate among DD, DCD and COM and to find the most discriminant regions. While no imaging index alone discriminated between the three groups, grouping grey and white matter volumes (structural model) or activity, local and global connectivity (functional model) made possible to discriminate among the DD, DCD and COM groups. The most important discrimination was obtained using the functional model, with regions in the cerebellum and the temporal lobe being the most discriminant for DCD and DD children, respectively. Results further showed that children with both DD and DCD have subtle but identifiable brain differences that can only be captured using several imaging indexes pertaining to both brain structure and function.

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.

Dyslexia with and without Irlen syndrome: A study of influence on abilities and brain-derived neurotrophic factor level.

The presence of comorbid Irlen syndrome (IS) in children with developmental dyslexia (DD) may have an impact on their reading and cognitive abilities. Furthermore, the brain-derived neurotrophic factor (BDNF) was reported to be expressed in brain areas involved in cognitive and visual processing. The aim of this study was to evaluate some cognitive abilities of a group of dyslexic children with IS and to measure and compare the plasma BDNF level to dyslexic children without IS and neurotypical (NT) children. The participants were 60 children with DD (30 in the DD + IS group; 30 in the DD group) and 30 NT children. The Irlen reading perceptual scale, the Stanford Binet intelligence scale, 4th ed, the dyslexia assessment test, and the Illinois test of psycholinguistic abilities were used. The BDNF level was measured using the enzyme-linked immunosorbent assay. One-minutewriting and visual closure deficits were more prevalent, while phonemic segmentation deficits were less prevalent in the DD + IS group compared to the DD group. The BDNF level in the DD groups was lower than that in NT children (p < 0.001). Some reading and non-reading tasks were influenced by the presence of a coexisting IS. The reduced BDNF level could play a role in the deficits noticed in the abilities of children with DD.

Failure to consolidate statistical learning in developmental dyslexia.

Statistical learning (SL), the ability to pick up patterns in sensory input, serves as one of the building blocks of language acquisition. Although SL has been studied extensively in developmental dyslexia (DD), much less is known about the way SL evolves over time. The handful of studies examining this question were all limited to the acquisition of motor sequential knowledge or highly learned segmented linguistic units. Here we examined memory consolidation of statistical regularities in adults with DD and typically developed (TD) readers by using auditory SL requiring the segmentation of units from continuous input, which represents one of the earliest learning challenges in language acquisition. DD and TD groups were exposed to tones in a probabilistically determined sequential structure varying in difficulty and subsequently tested for recognition of novel short sequences that adhered to this statistical pattern in immediate and delayed-recall sessions separated by a night of sleep. SL performance of the DD group at the easy and hard difficulty levels was poorer than that of the TD group in the immediate-recall session. Importantly, DD participants showed a significant overnight deterioration in SL performance at the medium difficulty level compared to TD, who instead showed overnight stabilization of the learned information. These findings imply that SL difficulties in DD may arise not only from impaired initial learning but also due to a failure to consolidate statistically structured information into long-term memory. We hypothesize that these deficits disrupt the typical course of language acquisition in those with DD.

Decontextualized Language Skills in Children with Developmental Language Disorder and Developmental Dyslexia: Evidence from a Word Definition Task

The present study investigates the development of decontextualized language skills, by means of a word definition task, in children with Developmental Language Disorder (DLD) &amp; Developmental Dyslexia (DD). Although these disorders have a common basis and have studied for different aspects of language abilities, no studies, to date, have compared them in terms of their word definitional skills. Addressing this gap, the present study examined thirty-six children with DLD, or DD or typically developing (TD) age-matched children. All participants were tested on their expressive vocabulary, non-verbal abilities and on their definitional skills. In the definitional task they had to define 16 words (8 nouns, 4 verbs, and 4 adjectives; simple vs. compound, abstract vs. concrete) orally. Definitions were evaluated on both content and form. Results have shown that more decontextualized language was used by the TD group than by the two impaired groups and the DD group exhibited the use of more decontextualized language than the DLD group. By contrast, no differences were found among the groups in form. Delving into different word characteristics more demanding were found to be abstract and compound words. DLD group faced more difficulties than the other groups in compound abstract nouns. Fewer differences were found in verbs suggesting that formal definitions of verbs are equally demanding for all groups. Findings suggest that these two disorders have more similarities in most of the categories in terms of the use of decontextualized language. The present study offers new knowledge on the development of definitional skills and indicates that research should investigate them in the light of interrelation of different word characteristics; otherwise the picture we get can be misleading.

Neural correlates of sequence learning in children with developmental dyslexia.

Developmental Dyslexia (DD) is a condition in which reading accuracy and/or fluency falls substantially below what is expected based on the individuals age, general level of cognitive ability, and educational opportunities. The procedural circuit deficit hypothesis (PDH) proposes that DD may be largely explained in terms of alterations of the cortico‐basal ganglia procedural memory system (in particular of the striatum) whereas the (hippocampus‐dependent) declarative memory system is intact, and may serve a compensatory role in the condition. The present study was designed to test this hypothesis. Using Magnetic Resonance Imaging, we examined the functional and structural brain correlates of sequence‐specific procedural learning (SL) on the serial reaction time task, in 17 children with DD and 18 typically developing (TD) children. The study was performed over 2 days with a 24‐h interval between sessions. In line with the PDH, the DD group showed less activation of the striatum during the processing of sequential statistical regularities. These alterations predicted the amount of SL at day 2, which in turn explained variance in children's reading fluency. Additionally, reduced hippocampal activation predicted larger SL gains between day 1 and day 2 in the TD group, but not in the DD group. At the structural level, caudate nucleus volume predicted the amount of acquired SL at day 2 in the TD group, but not in the DD group. The findings encourage further research into factors that promote learning in children with DD, including through compensatory mechanisms.

The influence of intelligence and cognitive abilities on the reading ability of Japanese students with developmental disorders

ObjectiveWe examined the differences in reading skills between Japanese students with developmental dyslexia (DD) having developmental disorders who had borderline IQ (BIQ) and those who had normal IQ (NIQ), and the influence of cognitive factors through subscale scores of the Wechsler Intelligence Scale for Children - Fourth Edition on the reading skills of all students with DD having developmental disorders. MethodsOne-way analysis of variance revealed differences in reading scores among the four groups (DD with NIQ, DD with BIQ, as well as non-DD with NIQ and non-DD with BIQ as control groups). To examine the influence of cognitive factors, we used multiple regression analysis for all participants, and then for participants with DD. ResultsRegarding hiragana nonword fluency reading, no difference was observed between the two DD groups, and cognitive factors did not affect the performance of all participants with DD. Concerning hiragana word fluency reading, DD with NIQ group performed better than DD group with BIQ, and working memory index affected reading skills of participants with DD. Regarding kanji accuracy reading, DD with NIQ group performed better than DD with BIQ group, and processing speed index affected performance of participants with DD. ConclusionsThe results of hiragana reading suggest that the two DD groups shared similar weak sub-lexical route processing, while the acquisition of lexical route processing was hindered by lower IQ and weak phonological working memory in transparent phonographic hiragana reading. For kanji reading, lower IQ and weak visuomotor processing ability hampered the learning of visually complex logographic kanji characters.

Global reading processes in children with high risk of dyslexia: a scanpath analysis.

The study presents the first systematic comparison of the global reading processes via scanpath analysis in Russian-speaking children with and without reading difficulties. First, we compared basic eye-movement characteristics in reading sentences in two groups of children in grades 1 to 5 (N = 72 in high risk of developmental dyslexia group and N = 72 in the control group). Next, using the scanpath method, we investigated which global reading processes these children adopt to read the entire sentence and how these processes differ between the groups. Finally, we were interested in the timeframe of the change in the global reading processes from the 1st to the 5th grades for both groups. We found that the main difference in word-level measures between groups was the reading speed reflected in fixation durations. However, the examination of the five identified global reading processes revealed qualitative similarities in reading patterns between groups. Children in the control group progressed quickly and by the 4th grade engaged in an adult-like fluent reading process. The high-risk group started with the beginner reading process, then similar to first graders in the control group, engaged mostly in the intermediate and upper-intermediate reading processes in 2nd to 4th grades. They reach the advanced process in the 5th grade, the same pattern preferred by the control group second graders. Overall, the scanpath analysis reveals that although there are quantitative differences in the word-level eye-tracking measures between groups, qualitatively children in the high-risk group read on par with typically developing peers but with a 3-year reading delay.