Selective predictive value of rapid automatized naming in poor readers

Verbal Working Memory-Balance program training alters the left fusiform gyrus resting-state functional connectivity: A randomized clinical trial study on children with dyslexia

Sufficient activation of the left fusiform gyrus is important in reading ability acquisition due to its role in reading and naming, working memory (WM), and balance tasks. Recently, a newly-designed training program, Verbal Working Memory-Balance (VWM-B), has been evaluated on children with dyslexia, and its positive effects were shown on reading ability, WM capacity, and postural control. In the present study, we aimed to estimate the functional connectivity alterations of the left fusiform gyrus following training by the VWM-B. Before and after 15 sessions of training, the fMRI and other tools data were collected on a sample of children with dyslexia, who were allocated into two control and experiment groups. Data analyses showed the increased functional connectivity of the left fusiform gyrus between the left anterior temporal fusiform cortex, left and right Crus II regions of the cerebellum, and the left middle frontal gyrus. Moreover, VWM-B training significantly improved the reading and naming ability, WM capacity, and postural control of participants in the experiment group in comparison to the control. The current study findings emphasize the critical role of the left fusiform gyrus in reading ability. Moreover, it provides evidence to support the existence of cerebellar deficits in dyslexia.

White matter correlates of reading subskills in children with and without reading disability

Individual differences in reading ability are associated with characteristics of white matter microstructure in the brain. However, previous studies have largely measured reading as a single construct, resulting in difficulty characterizing the role of structural connectivity in discrete subskills of reading. The present study used diffusion tensor imaging to examine how white matter microstructure, measured by fractional anisotropy (FA), relates to individual differences in reading subskills in children aged 8 to 14 (n = 65). Findings showed positive correlations between FA of the left arcuate fasciculus and measures of single word reading and rapid naming abilities. Negative correlations were observed between FA of the right inferior longitudinal fasciculus and bilateral uncinate fasciculi, and reading subskills, particularly reading comprehension. The results suggest that although reading subskills rely to some extent on shared tracts, there are also distinct characteristics of white matter microstructure supporting different components of reading ability in children.

Resting-state functional connectivity and reading subskills in children

Individual differences in reading ability have been linked to characteristics of functional connectivity in the brain in both children and adults. However, many previous studies have used single or composite measures of reading, leading to difficulty characterizing the role of functional connectivity in discrete subskills of reading. The present study addresses this issue using resting-state fMRI to examine how resting-state functional connectivity (RSFC) related to individual differences in children's reading subskills, including decoding, sight word reading, reading comprehension, and rapid automatized naming (RAN). Findings showed both positive and negative RSFC-behaviour relationships that diverged across different reading subskills. Positive relationships included increasing RSFC among left dorsal and anterior regions with increasing decoding proficiency, and increasing RSFC between the left thalamus and right fusiform gyrus with increasing sight word reading, RAN, and reading comprehension abilities. In contrast, negative relationships suggested greater functional segregation of attentional and reading networks with improved performance on RAN, decoding, and reading comprehension tasks. Importantly, the results suggest that although reading subskills rely to some extent on shared functional networks, there are also distinct functional connections supporting different components of reading ability in children.

Rapid serial naming: Developmental trajectory and relationship with the Bangor Dyslexia Test in Spanish students

This study aimed to analyse the developmental trajectory of the accuracy and speed of naming among dyslexics and developing readers from 1st to 6th grade of primary education. It examined how familiarity with the stimulus influences the performance of different naming tasks in both groups and evaluated the link between naming speed and the Bangor Dyslexia Test. With a descriptive and correlational design, eight naming tasks and the Bangor Dyslexia Test (Miles, 1982; Outón & Suárez, 2010) were administered to a sample of 198 dyslexics and 245 developing readers. The results showed that the dyslexics were slower and more inaccurate in all the naming tasks, compared with the developing readers of the same age. Greater difficulty was observed with the less familiar stimuli. It became evident that naming performance improved with age among both groups of subjects. Finally, a greater number of significant and positive correlations were found between the naming tasks and the Bangor Dyslexia Test in the dyslexic group; the strongest relationship was obtained by naming letters.

Predicting Dyslexia in Children With Developmental Language Disorder

Purpose In this study, we examine how well kindergarten letter identification and phonological awareness predict 2nd grade word reading and dyslexia in children with developmental language disorder (DLD) and their age- and grade-matched peers with typical language (TL). Method We employ (a) logistic regression to determine how letter identification and phonological awareness predict dyslexia, that is, dichotomous categorization of good or poor word reading, in children with DLD and TL and (b) quantile regression to determine how letter identification and phonological awareness are associated with word reading abilities on a continuum in these groups of children. Results Logistic regression revealed that letter identification was the only significant, unique kindergarten predictor of dyslexia in 2nd grade children with DLD, when compared to phonological awareness. In children with TL, both kindergarten letter identification and phonological awareness significantly predicted dyslexia in 2nd grade. Quantile regression revealed that kindergarten letter identification was a stronger predictor of 2nd grade word reading for average and lower achieving word readers with DLD and their peers with TL compared to higher performing readers. Phonological awareness was weakly associated with word reading across the full continuum of word reading abilities in children with DLD. Conclusion Letter identification is a more accurate predictor of poor word reading and dyslexia than phonological awareness in kindergarten children with DLD, which has important implications for recent U.S. legislation around early identification of dyslexia in all children.

Visual information processing skills are associated with academic performance in Grade 2 school children

PURPOSE

This study evaluated the association between performance on visual information processing tests and academic performance in school children.

METHODS

Visual-motor integration (VMI), the Developmental Eye Movement (DEM) test, visual acuity and stereoacuity were assessed in 222 Grade 2 children (mean age: 7.90 ± 0.33 years). Academic performance was assessed using standardized tests of reading and mathematics (PAT-R and PAT-M). Linear regression analyses examined associations between visual information processing (VMI and DEM) and academic measures, adjusting for school socio-economic background and age. Receiver operating characteristic (ROC) analysis was used to assess the ability of the tests to identify children with below average academic performance.

RESULTS

Visual-motor integration (VMI) and DEM (horizontal time) were most strongly associated with PAT-R and PAT-M. Linear regression models explained 28.6% of variance in PAT-R (VMI: standardized regression coefficient = 0.31, p < 0.01; DEM horizontal time: -0.28, p < 0.01) and 24.1% of variance in PAT-M (VMI: standardized regression coefficient = 0.29, p < 0.01; DEM horizontal time: -0.16, p = 0.02). Receiver operating characteristic (ROC) curve analysis indicated that VMI was most strongly associated with below average PAT-R (area under curve [AUC] of 0.74 [95% CI: 0.67-0.81]) and PAT-M (AUC of 0.73 [95% CI: 0.66-0.81]).

CONCLUSION

Visual-motor integration (VMI) was most strongly associated with reading and mathematics scores in school children. A child's academic performance can be an important factor in their optometric management. The ability of clinical tests to identify children at risk of underachieving academically provides additional support to clinicians in managing their patients.

Diagnostic implications of the double deficit model for young adolescents with dyslexia

Considerable support exists for both the phonological core deficit and the naming speed deficit models of dyslexia. The double deficit model proposed that many students with dyslexia might also be impaired in both underlying processes. Employing either performance thresholds (i.e., scores below the 16th or 25th percentile) or k-means clustering as classification methods, the current study investigated whether 154 young adolescents with dyslexia could be categorized into subtypes according to the presence or absence of phonological deficits alone, naming speed deficits alone, or a combination of the two and whether group composition changed depending on classification method. Results support the existence of both single and double deficit groups and confirm that those with both deficits are the most severely impaired across multiple measures. Contrary to previous research, most adolescents were classified as either naming speed only (about a third of the group) or double deficit when defining impairment using performance thresholds to classify groups. This may suggest that although early phonological deficits are amenable to remediation, identification of language symbols fails to become automatized in most individuals with dyslexia and may require more targeted intervention. Classification differences reported in the literature may depend on age and methods employed for classification.

Rapid automatized naming in a developmental perspective between ages 4 and 10

During the last decades, rapid automatized naming (RAN) has been widely examined as a predictor of reading ability, but very few studies have examined the development of RAN itself. The present study followed children from ages 4 until 10, focusing on RAN performance in a developmental perspective. Relations within and between alphanumeric and nonalphanumeric RAN were investigated both concurrently and over time. The result shows that individual differences in RAN objects are stable between ages 4 and 10, with the most rapid growth of mean performance between ages 4 and 6. Early performance on RAN objects predicts both performance on RAN digits and RAN letters at age 8 and the further development between ages 8 and 10. Further, low-performing children at age 4 develop their performance on RAN digits and RAN letters later compared with high-performing children, and RAN digits performance reaches a plateau earlier than RAN letters performance.

The effect of phonological awareness on rapid automatized naming

Background: Phonological awareness (PA) is a fundamental predictor of reading disability. However, researches on reading have indicated that PA assessment alone is not sufficient to prevent reading problems. Rapid automatized naming (RAN) has been suggested as another influential factor in reading deficits independent of PA. This study investigated the impact of phonological awareness on rapid automatized naming.

Methods: This was a randomized clinical trial study in which 62 Persian monolingual first graders were recruited from 3 schools using convenience sampling. Inclusion criteria were lack of deficits with sensory-motor skills and knowledge of the Persian alphabets. Measures of PA and RAN were utilized. The participants were randomly assigned into either the intervention or the control group. The intervention group was divided into small groups of 4-6 children who received thirty 40-minute training sessions in PA. T test, Mann-Whitney, and Wilcoxon tests were used for data analysis.

Results: The results revealed that the RAN time was significantly reduced (p≤0.001), with a significant increase in PA scores (p≤0.001). In addition, there was a significant inverse relationship between some of the measures of the phonological awareness subtests and rapid automatized naming (eg, phonemic blending & RAN (numbers): ρ=-0.52 with p≤0.001).

Conclusion: The findings showed that in the initial assessment, PA and RAN had a significant relationship, but RAN could be significantly improved by PA training.

An Exploration of the Rapid Automatic Naming Test as Administered to Brazilian Children

OBJECTIVE

The purpose of this research was to conduct an exploratory study of the performance of Brazilian children on the Rapid Automatic Naming (RAN) test, examining schooling effects of schooling and associations with reading speed, comprehension, and reading level for each of the RAN subtests of colour, numbers, letters, and objects.

METHODS

Participants were 97 children, aged 7-11 years, enrolled in the first to fifth grade of elementary public education.

RESULTS

The findings indicated a school-year effect on RAN performance, with recurrent differences in grades 1-4 and no effect in RAN Numbers. Correlations ranged from moderate to high for reading level, speed, and comprehension. In addition, multiple linear regression analysis indicated that RAN Letters could significantly predict performance in the three reading abilities studied.

CONCLUSION

Thus, the study provided initial evidence of RAN's performance in testing Brazilian children's phonological processing as a form of predictive monitoring of reading development in school-age children as it relates to scholastic progress and reading speed, comprehension, and level.

The Relationship Between Reading Fluency and Arithmetic Fact Fluency and Their Shared Cognitive Skills: A Developmental Perspective

This study investigated the underlying cognitive abilities which are related to both fluency in reading and arithmetic across different developmental phases of their acquisition. An unselected sample of children in first (N = 83), second (N = 66), and third (N = 67) grades completed several reading and arithmetic fluency tasks, as well as rapid automatized naming (RAN), working memory (WM), and inhibition measures. The results of a stepwise regression analysis revealed differences in the predictive models of fluency in both academic domains in first grade. However, similar patterns were found in the second and third grades. Specifically, in first grade reading fluency was predicted by inhibition and WM, while arithmetic fact fluency was predicted by RAN and WM. In contrast, in second grade both types of fluency were predicted by RAN and WM, and in third grade only RAN was found to be a predictor. Alongside the gradual reduction in the cognitive components participating in reading and arithmetic fluency, the results of the present study suggest that both fluencies share the same underlying cognitive mechanisms. Practical implications of the current results are discussed.

Can the Relationship Between Rapid Automatized Naming and Word Reading Be Explained by a Catastrophe? Empirical Evidence From Students With and Without Reading Difficulties

The purpose of the present study was to explain the moderating role of rapid automatized naming (RAN) in word reading with a cusp catastrophe model. We hypothesized that increases in RAN performance speed beyond a critical point would be associated with the disruption in word reading, consistent with a "generic shutdown" hypothesis. Participants were 587 elementary schoolchildren (Grades 2-4), among whom 87 had reading comprehension difficulties per the IQ-achievement discrepancy criterion. Data were analyzed via a cusp catastrophe model derived from the nonlinear dynamics systems theory. Results indicated that for children with reading comprehension difficulties, as naming speed falls below a critical level, the association between core reading processes (word recognition and decoding) becomes chaotic and unpredictable. However, after the significant common variance attributed to motivation, emotional, and internalizing symptoms measures from RAN scores was partialed out, its role as a bifurcation variable was no longer evident. Taken together, these findings suggest that RAN represents a salient cognitive measure that may be associated with psychoemotional processes that are, at least in part, responsible for unpredictable and chaotic word reading behavior among children with reading comprehension deficits.

How Many U.S. High School Students Have a Foreign Language Reading "Disability"? Reading Without Meaning and the Simple View

Conventional wisdom suggests that students classified as learning disabled will exhibit difficulties with foreign language (FL) learning, but evidence has not supported a relationship between FL learning problems and learning disabilities. The simple view of reading model posits that reading comprehension is the product of word decoding and language comprehension and that there are good readers and 3 types of poor readers-dyslexic, hyperlexic, and garden variety-who exhibit different profiles of strengths and/or deficits in word decoding and language comprehension. In this study, a random sample of U.S. high school students completing first-, second-, and third-year Spanish courses were administered standardized measures of Spanish word decoding and reading comprehension, compared with monolingual Spanish readers from first to eleventh grades, and classified into reader types according to the simple view of reading. The majority of students fit the hyperlexic profile, and no participants fit the good reader profile until they were compared with first- and second-grade monolingual Spanish readers. Findings call into question the practice of diagnosing an FL "disability" before a student engages in FL study.

Desempenho do processamento fonológico, leitura e escrita em escolares com transtorno de déficit de atenção e hiperatividade

RESUMO Objetivo: comparar o desempenho do processamento fonológico, da leitura e escrita de palavras reais e inventadas entre os escolares com transtorno de déficit de atenção e hiperatividade e escolares com bom desempenho escolar. Métodos: participaram deste estudo 30 escolares, na faixa etária de 9 a 12 anos, de ambos os gêneros, do Ensino Fundamental de escolas públicas e particulares, divididos em: Grupo Experimental (15 escolares com diagnóstico interdisciplinar de transtorno de déficit de atenção e hiperatividade) e Grupo Controle (15 escolares com bom desempenho escolar), pareado com o Grupo Experimental em idade, gênero, escolaridade, tipo de instituição de ensino (pública e particular). Os instrumentos utilizados para avaliação foram: Instrumento de Avaliação Sequencial (CONFIAS), Teste de Nomeação Seriada Rápida (RAN), Prova de repetição de palavras sem significado e Prova de leitura e escrita. Os resultados foram analisados por meio de testes estatísticos (Mann Whitney e Teste t de Student), adotando-se nível de significância de 5% (0,05). Resultados: os resultados analisados por meio de testes estatísticos revelaram diferenças significantes entre o grupo experimental e o grupo controle nas provas avaliadas. Conclusão: escolares com transtorno de déficit de atenção e hiperatividade apresentaram desempenho inferior em habilidades de consciência fonológica, acesso ao léxico, memória operacional, leitura e escrita de palavras, quando comparados aos escolares sem transtorno de déficit de atenção e hiperatividade, com bom desempenho escolar.

Beyond Phonology: Visual Processes Predict Alphanumeric and Nonalphanumeric Rapid Naming in Poor Early Readers

Visual processes in Grade 1 were examined for their predictive influences in nonalphanumeric and alphanumeric rapid naming (RAN) in 51 poor early and 69 typical readers. In a lagged design, children were followed longitudinally from Grade 1 to Grade 3 over 5 testing occasions. RAN outcomes in early Grade 2 were predicted by speeded and nonspeeded visual processing measures, after controlling for initial (Grade 1) RAN, matrix reasoning, phonological awareness, and word decoding abilities. A predictive influence of backward visual masking-a speeded visual discrimination task-was found for nonalphanumeric RAN in early Grade 2 but not for alphanumeric RAN or subsequent RAN ability in Grades 2 and 3. A nonspeeded predictor involving controlled visual attention accounted for significant variance in early Grade 2 RAN in the poor early reader group. Results are discussed in relation to Wolf, Bowers, and Biddle's conceptualization of rapid naming-in particular, on the roles of visual processes in speeded low and nonspeeded high spatial frequency visual information in predicting RAN.

Double-Deficit Hypothesis in a Clinical Sample: Extension Beyond Reading

This study explored the double-deficit hypothesis (DDH) in a transparent orthography (Finnish) and extended the view from reading disabilities to comorbidity of learning-related problems in math and attention. Children referred for evaluation of learning disabilities in second through sixth grade (N = 205) were divided into four groups based on rapid automatized naming (RAN) and phonological awareness (PA) according to the DDH: the double-deficit group, the naming speed deficit-only group, the phonological deficit-only group, and the no-deficit group. The results supported the DDH in that the prevalence and severity of reading disability were greatest in the double-deficit group. Despite the greater prevalence of reading disabilities in single-deficit groups compared to the no-deficit group, the means of reading measures in the single-deficit groups were similar to those of the no-deficit group. The PA single-deficit group was poorer in spelling than the no-deficit group and single-naming-deficit group. Deficits in RAN or PA were primarily linked to reading disabilities but not with math or attention problems. The results supported the DDH partially and indicate that deficits in RAN and PA are specific to reading disabilities.

Reading Disabilities Related to Word Recognition: Underlying Deficits and Diagnostic Approaches

This article provides an overview of the underlying core deficits (i.e., phonological processing, rapid naming speed, and the "double deficit" hypothesis) believed to be associated with reading disabilities in the word recognition area. In order to emphasize the importance of accurate diagnosis, examples of appropriate intervention strategies for the different deficit areas are presented. This is followed by a general discussion of current assessment practices. Although school systems typically utilize IQ-achievement discrepancy analysis for identifying reading disabilities in children, this procedure appears to have a number of shortcomings. Alternative approaches for identifying children with reading disabilities related to word recognition are offered.

Development of Rapid Automatized Naming (RAN) in Simultaneous Kannada-English Biliterate Children

RAN tests were administered to 600 typically developing children, 60 each from grade level one through grade ten (30 boys and 30 girls), who learn two distinct languages, English and Kannada simultaneously from the very first grade. The overall results were in accordance with similar previous studies in English and other European languages. The developmental trajectories were similar across the languages to a large extent; but the results also showed some differences across languages with respect to synchrony between the measures and the overall naming speed. Though some of the differences could be ascribed to the bilingual/biliterate culture and language use, there are enough scopes for future researches to examine these issues.

Decoding skills in children with language impairment: contributions of phonological processing and classroom experiences

PURPOSE

Children with language impairment (LI) often demonstrate difficulties with word decoding. Research suggests that child-level (i.e., phonological processing) and environmental-level (i.e., classroom quality) factors both contribute to decoding skills in typically developing children. The present study examined the extent to which these same factors influence the decoding skills of children with LI, and the extent to which classroom quality moderates the relationship between phonological processing and decoding.

METHOD

Kindergarten and first-grade children with LI (n = 198) were assessed on measures of phonological processing and decoding twice throughout the academic year. Live classroom observations were conducted to assess classroom quality with respect to emotional support and instructional support.

RESULTS

Hierarchical regression analyses revealed that of the 3 phonological processing variables included, only phonological awareness significantly predicted spring decoding outcomes when controlling for children's age and previous decoding ability. One aspect of classroom quality (emotional support) was also predictive of decoding, but there was no significant interaction between classroom quality and phonological processing.

CONCLUSIONS

This study provides further evidence that phonological awareness is an important skill to assess in children with LI and that high-quality classroom environments can be positively associated with children's decoding outcomes.

Genome scan for cognitive trait loci of dyslexia: Rapid naming and rapid switching of letters, numbers, and colors

Dyslexia, or specific reading disability, is a common developmental disorder that affects 5-12% of school-aged children. Dyslexia and its component phenotypes, assessed categorically or quantitatively, have complex genetic bases. The ability to rapidly name letters, numbers, and colors from rows presented visually correlates strongly with reading in multiple languages and is a valid predictor of reading and spelling impairment. Performance on measures of rapid naming and switching, RAN and RAS, is stable throughout elementary school years, with slowed performance persisting in adults who still manifest dyslexia. Targeted analyses of dyslexia candidate regions have included RAN measures, but only one other genome-wide linkage study has been reported. As part of a broad effort to identify genetic contributors to dyslexia, we performed combined oligogenic segregation and linkage analyses of measures of RAN and RAS in a family-based cohort ascertained through probands with dyslexia. We obtained strong evidence for linkage of RAN letters to the DYX3 locus on chromosome 2p and RAN colors to chromosome 10q, but were unable to confirm the chromosome 6p21 linkage detected for a composite measure of RAN colors and objects in the previous genome-wide study.

Association of the ROBO1 gene with reading disabilities in a family-based analysis

Linkage studies have identified a locus on chromosome 3 as reading disabilities (RD) and speech and sound disorder (SSD) susceptibility region, with both RD and SSD sharing similar phonological processing and phonological memory difficulties. One gene in this region, roundabout homolog 1 (ROBO1), has been indicated as a RD candidate and has shown significant association with measures of phonological memory in a population-based sample. In this study, we conducted a family-based association analysis using two independent samples collected in Toronto and Calgary, Canada. Using the two samples, we tested for association between ROBO1 single nucleotide polymorphisms (SNPs) and RD, along with quantitative measures for reading, spelling and phonological memory. One SNP, rs331142, which was selected based on its correlation with ROBO1 expression in brain tissue, was found to be significantly associated with RD in the Toronto sample with over transmission of the minor C allele (P = 0.001), correlated with low expression. This SNP is located ~200 bp from a putative enhancer and results for a marker within the enhancer, rs12495133, showed evidence for association with the same allele in both the Toronto and Calgary samples (P = 0.005 and P = 0.007). These results support previous associations between ROBO1 and RD, as well as correlation with low gene expression, suggesting a possible mechanism of risk conferred by this gene.

The neural correlates of reading fluency deficits in children

Multiple studies have shown that individuals with a reading disability (RD) demonstrate deficits in posterior left-hemispheric brain regions during reading-related tasks. These studies mainly focused on reading sub-skills, and it remains debated whether such dysfunction is apparent during more ecologically valid reading skills, such as reading fluency. In this fMRI study, reading fluency was systematically varied to characterize neural correlates of reading fluency in 30 children with (RD) and without (typical developing children, TYP) a RD. Sentences were presented at constrained, comfortable, and accelerated speeds, which were determined based on individual reading speed. Behaviorally, RD children displayed decreased performance in several reading-related tasks. Using fMRI, we demonstrated that both TYP and RD children display increased activation in several components of the reading network during fluent reading. When required to read at an accelerated speed, RD children exhibited less activation in the fusiform gyrus (FG) compared with the TYP children. A region of interest analysis substantiated differences in the FG and demonstrated a relationship to behavioral reading performance. These results suggest that the FG plays a key role in fluent reading and that it can be modulated by speed. These results and their implications for remediation strategies should be considered in educational practice.

Relationships among cognitive deficits and component skills of reading in younger and older students with developmental dyslexia

Processing speed deficits along with phonological awareness deficits have been identified as risk factors for dyslexia. This study was designed to examine the behavioral profiles of two groups, a younger (6-8 years) and an older (10-15 years) group of dyslexic children for the purposes of (1) evaluating the degree to which phonological awareness and processing speed deficits occur in the two developmental cohorts; (2) determining the strength of relationships between the groups' respective mean scores on cognitive tasks of phonological awareness and processing speed and their scores on component skills of reading; and (3) evaluating the degree to which phonological awareness and processing speed serve as concurrent predictors of component reading skills for each group. The mean scaled scores for both groups were similar on all but one processing speed task. The older group was significantly more depressed on a visual matching test of attention, scanning, and speed. Correlations between reading skills and the cognitive constructs were very similar for both age-groups. Neither of the two phonological awareness tasks correlated with either of the two processing speed tasks or with any of the three measures of reading. One of the two processing speed measures served as a concurrent predictor of word- and text-level reading in the younger, however, only the rapid naming measure functioned as a concurrent predictor of word reading in the older group. Conversely, phonological processing measures did not serve as concurrent predictors for word-level or text-level reading in either of the groups. Descriptive analyses of individual subjects' deficits in the domains of phonological awareness and processing speed revealed that (1) both linguistic and nonlinguistic processing speed deficits in the younger dyslexic children occurred at higher rates than deficits in phonological awareness and (2) cognitive deficits within and across these two domains were greater in the older dyslexic children. Our findings underscore the importance of using rapid naming measures when testing school-age children suspected of having a reading disability and suggest that processing speed measures that do not reply on verbal responses may serve as predictors of reading disability in young children prior to their development of naming automaticity.

Rapid automatized naming and immediate memory functions in Chinese children who read English as a second language

This study examined reading performance of 102 Chinese Mandarin-speaking 4th graders in their second language (L2, English) as a function of performance in their first language (L1, Chinese). The results revealed that for Rapid Automatized Naming (RAN) and Rapid Alternating Stimulus (RAS) measures, the mean naming time decreased monotonically in high-achieving, average, and low-achieving readers. RAN and RAS differentiated poor readers from good and average readers but failed to differentiate between good and average readers. RAN deficits occurred in poor readers in both languages. Comparison of memory profiles revealed that patterns varied depending on the mode of stimulus presentation or response. Low-achieving readers performed poorly on a subtest involving visual components only and did relatively better on a subtest involving verbal components only. Poor readers in Chinese also encountered difficulties in learning English as a L2. RAN-character accounted for unique variance in two Chinese reading measures. RAN-letter explained unique variance in English mid-term reading grade. The unique variance captured by the Color Span Subtest 1 (visual-visual) was found in Chinese reading comprehension but not in English reading comprehension. Reading performance in L1 was predictive of reading performance in L2 and vice versa.

Eye-voice span during rapid automatized naming of digits and dice in Chinese normal and dyslexic children

We measured Chinese dyslexic and control children's eye movements during rapid automatized naming (RAN) with alphanumeric (digits) and symbolic (dice surfaces) stimuli. Both types of stimuli required identical oral responses, controlling for effects associated with speech production. Results showed that naming dice was much slower than naming digits for both groups, but group differences in eye-movement measures and in the eye-voice span (i.e. the distance between the currently fixated item and the voiced item) were generally larger in digit-RAN than in dice-RAN. In addition, dyslexics were less efficient in parafoveal processing in these RAN tasks. Since the two RAN tasks required the same phonological output and on the assumption that naming dice is less practiced than naming digits in general, the results suggest that the translation of alphanumeric visual symbols into phonological codes is less efficient in dyslexic children. The dissociation of the print-to-sound conversion and phonological representation suggests that the degree of automaticity in translation from visual symbols to phonological codes in addition to phonological processing per se is also critical to understanding dyslexia.

Sex-specific gray matter volume differences in females with developmental dyslexia

Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men, we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences, and instead, we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e., motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia.

Is rapid automatized naming related to reading and mathematics for the same reason(s)? A follow-up study from kindergarten to Grade 1

We examined (a) what rapid automatized naming (RAN) components (articulation time and/or pause time) predict reading and mathematics ability and (b) what processing skills involved in RAN (speed of processing, response inhibition, working memory, and/or phonological awareness) may explain its relationship with reading and mathematics. A sample of 72 children were followed from the beginning of kindergarten until the end of Grade 1 and were assessed on measures of RAN, general cognitive ability, speed of processing, attention, working memory, phonological awareness, reading, and mathematics. The results indicated that pause time was the critical component in both the RAN-reading and RAN-mathematics relationships and that it shared most of its predictive variance in reading and mathematics with speed of processing and working memory. Our findings further suggested that, unlike the relationship between RAN and reading fluency in Grade 1, there is nothing in the RAN task that is uniquely related to math.

Rapid Naming Tests: Developmental Course and Relations with Neuropsychological Measures

A Digits Rapid Automatized Naming (RAN) test and a Colors and Shapes Rapid Alternating Stimulus (RAS) test were administered to 904 Portuguese, normally achieving children (ages 7 to 15), in order to examine these tests scores developmental course. The results showed that the two tests have slightly different developmental trajectories. In addition, the two tests associations with a large number of neuropsychological measures were determined in three age groups (7-9 years, n = 301; 10-12 years, n = 299; 13-15 years, n = 304). The neuropsychological measures addressed attention/executive functions, motor behavior, verbal memory, visual memory and language. The results indicated that each one of the rapid naming tests brings into play not entirely coincident processes. Although, they converge in terms of their associations with language and attention measures, Colors and Shapes RAS test is more demanding in cognitive and linguistic terms. In addition, while Digits RAN test has little in common with short-term memory, Colors and Shapes RAS test relates moderately with short-term memory, due to the increased demands in terms of effort, access and retrieval of the phonological labels that correspond to the different stimuli categories. The need to differentiate between the two rapid naming tests is supported.

Is weak oral language associated with poor spelling in school-age children with specific language impairment, dyslexia or both?

The purpose of this study was to test the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in school-age children. We compared fourth grade spelling accuracy in children with specific language impairment (SLI), dyslexia or both (SLI/dyslexia) to their typically developing grade-matched peers. Results of the study revealed that children with SLI performed similarly to their typically developing peers on a single-word spelling task. Alternatively, those with dyslexia and SLI/dyslexia evidenced poor spelling accuracy. Errors made by both those with dyslexia and SLI/dyslexia were characterized by numerous phonologic, orthographic and semantic errors. Cumulative results support the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in typically developing school-age children and their peers with SLI and dyslexia. Findings are provided as further support for the notion that SLI and dyslexia are distinct, yet co-morbid, developmental disorders.

Rapid naming speed components and reading development in a consistent orthography

We examined how rapid automatized naming (RAN) components-articulation time and pause time-predict word and text reading fluency in a consistent orthography (Greek). In total, 68 children were followed from Grade 2 to Grade 6 and were assessed three times on RAN (Digits and Objects), phonological awareness, orthographic processing, speed of processing, and reading fluency. Both RAN components were strongly related to reading fluency and, with few exceptions, accounted for unique variance over and above the contribution of speed of processing, phonological awareness, and orthographic processing. The amount of predictive variance shared between the components and the cognitive processing skills varied across time. The implications of these findings for the RAN-reading relationship are discussed.

Mapping for dyslexia and related cognitive trait loci provides strong evidence for further risk genes on chromosome 6p21

In a genome-wide linkage scan, we aimed at mapping risk loci for dyslexia in the German population. Our sample comprised 1,030 individuals from 246 dyslexia families which were recruited through a single-proband sib pair study design and a detailed assessment of dyslexia and related cognitive traits. We found evidence for a major dyslexia locus on chromosome 6p21. The cognitive trait rapid naming (objects/colors) produced a genome-wide significant LOD score of 5.87 (P = 1.00 × 10⁻⁷) and the implicated 6p-risk region spans around 10 Mb. Although our finding maps close to DYX2, where the dyslexia candidate genes DCDC2 and KIAA0319 have already been identified, our data point to the presence of an additional risk gene in this region and are highlighting the impact of 6p21 in dyslexia and related cognitive traits.

Executive working memory processes in dyslexia: behavioral and fMRI evidence

Dyslexia is an impairment in learning to read and write, primarily associated with a phonological core deficit. However, the manifestation of symptoms in dyslexia also includes impaired working memory (WM). The aim of this study was to investigate cortical activation related to verbal WM in dyslexic and normal readers aged around 13 years, controlling for phonological awareness processing. We used a modified WM n-back task where the participants remembered the first or last speech segment (phonemes) of the names of common objects shown as pictures. Dyslexic readers were impaired compared with the control group. Compared with the dyslexic readers, controls showed increased fMRI activation in the left superior parietal lobule and the right inferior prefrontal gyrus. Unlike controls, dyslexics did not show a significant increase in activation in WM areas with increased memory load. These findings provide support for a specific working memory deficit in dyslexic individuals.

Longitudinal Stability of Reading-Related Skills and their Prediction of Reading Development

Individual differences in word recognition, spelling, and reading comprehension for 324 children at a mean age of 16 were predicted from their reading-related skills (phoneme awareness, phonological decoding, rapid naming and IQ) at a mean age of 10 years, after controlling the predictors for the autoregressive effects of the correlated reading skills. There were significant and longitudinally stable individual differences for all four reading-related skills that were independent from each of the reading and spelling skills. Yet the only significant longitudinal prediction of reading skills was from IQ at mean age 10 for reading comprehension at mean age 16. The extremely high longitudinal latent-trait stability correlations for individual differences in word recognition (.98) and spelling (.95) left little independent outcome variance that could be predicted by the reading-related skills. We discuss the practical and theoretical importance of these results and why they differ from studies of younger children.

Rapid automatized naming and immediate memory functions in Chinese Mandarin-speaking elementary readers

The purpose of this study was to evaluate rapid automatized naming skills (RAN) and immediate memory processes in 243 Chinese Mandarin-speaking elementary readers (ranging from Grade 1 to Grade 5). For RAN subtests, the mean naming time decreased monotonically with grade level in good and average readers, and a similar trajectory was found in poor readers, even though they were generally slower in rapid naming. Regardless of grouping methods (counting all participants or counting good readers only), RAN Character emerged as a significant predictor of various Chinese reading measures. Different from classical findings in English readers indicating that RAN Number was a better correlate of reading than RAN Object, RAN Object outperformed RAN Number and became a significant predictor of Chinese reading speed and spelling, suggesting that the differences in predictive power of RAN tasks may be language specific. Comparison of memory profiles for good, average, and poor readers revealed that the patterns varied depending on mode of stimulus presentation or response. Poor readers performed poorly on subtests involving a visual component and did relatively better on subtests involving verbal cues only, whereas a reversed pattern was shown in the group of good readers. The findings were interpreted to suggest that good and poor Chinese readers may be essentially different in applying visual strategies and verbal mediation during visual-verbal intra- and intermodal processing, and visual skills appear to be particularly important in reading of Chinese.

Association of reading disability on chromosome 6p22 in the Afrikaner population

The genetic basis of reading disability (RD) has long been established through family and twin studies. More recently genetic linkage studies have identified genomic regions that appear to harbor susceptibility genes for RD. Association studies have been shown to have greater power for detecting genes of modest effect, particularly in genetically isolated populations. Hence, a case control study of RD was undertaken in the Afrikaner population in South Africa. Sixty-eight microsatellite markers in regions where linkages had been reported in previous studies were genotyped on 122 children with reading disability and 112 typically reading controls drawn from the same school population. A single allele of marker D6S299 showed a highly significant association with the RD phenotype (D6S299[229], P-value 0.000014). Other markers on other chromosomes also showed suggestive associations. Of particular interest were markers on chromosomes 1 and 15. These two regions have been implicated in studies of populations that formed the founding population in the Afrikaner population.

An experimental comparison between rival theories of rapid automatized naming performance and its relationship to reading

Two studies investigated the degree to which the relationship between rapid automatized naming (RAN) performance and reading development is driven by shared phonological processes. Study 1 assessed RAN, phonological awareness, and reading performance in 1010 7- to 10-year-olds. Results showed that RAN deficits occurred in the absence of phonological awareness deficits. These were accompanied by modest reading delays. In structural equation modeling, solutions where RAN was subsumed within a phonological processing factor did not provide a good fit to the data, suggesting that processes outside phonology may drive RAN performance and its association with reading. Study 2 investigated Kail's proposal that speed of processing underlies this relationship. Children with single RAN deficits showed slower speed of processing than did closely matched controls performing normally on RAN. However, regression analysis revealed that RAN made a unique contribution to reading even after accounting for processing speed. Theoretical implications are discussed.

Evaluation of the double-deficit hypothesis subtype classification of readers in Spanish

The double-deficit hypothesis acknowledges both phonological processing deficits and serial naming speed deficits as two dimensions associated with reading disabilities. The purpose of this study was to examine these two dimensions of reading as they were related to the reading skills of 29 Spanish average readers and poor readers (mean age 9 years 7 months) who met the criteria for either single phonological deficit (PD), double deficit (DD), or no deficit. DD children were the slowest readers and had the weakest orthography processing skills. No significant differences were found between PD and DD groups on word and pseudoword reading. Word reading and reading comprehension skills were average or above average in the three studied groups. As in previous studies in transparent orthographies, word reading was not a salient problem for Spanish poor readers, whereas for the DD group, reading speed and orthographic recognition skills were significantly affected.

Rapid naming, not cancellation speed or articulation rate, predicts reading in an orthographically regular language (Italian)

This study examined the influence of rapid automatization naming (RAN) measures on various parameters of reading performance in children who were native speakers of a language with a shallow orthography (Italian). Participants included 281 children enrolled in first-to-sixth grade. They were given a Naming test, in which they had to name rapidly matrices of colors, objects, or digits, a Cancellation test, using the same stimulus materials, and an oral Articulation test. Performance on all tests improved steadily across ages tested. Performance on the Naming test, but not on the Cancellation and Articulation tests, predicted speed and accuracy in reading; none of these measures reliably predicted the reading comprehension measure. Data on a Blending test were also available for a subsample of first- and third-graders. Both RAN and phonological ability contributed independently to the prediction of reading ability (accuracy and speed) in these participants. The results extend observations on RAN to an orthographically shallow language (Italian) and suggest an element of continuity between languages with opaque and transparent orthographies.

Naming Speed and Visual Search Deficits in Readers With Disabilities: Evidence From an Orthographically Regular Language (Italian)

The study examined rapid automatized naming (RAN) in 42 children with reading disabilities and 101 control children-all native speakers of Italian, a language with shallow orthography. Third-, 5th- and 6th-grade children were given a RAN test that required rapid naming of color, object, or digit matrices. A visual search test using the same stimulus material (but not requiring a verbal response) and an oral articulation test were also given. Readers with disabilities performed worse than controls on the RAN test. This effect was larger in higher grades than in lower ones. Readers with disabilities were also slower than controls in performing the visual search test. The pattern of results for the RAN test held constant when the visual search performance was partialed out by covariance analysis, indicating the independence of the 2 deficits. The 2 groups did not differ for articulation rate. Finally, analysis of the pattern of intercorrelations indicated that reading speed was most clearly related to RAN, particularly in the group with reading disabilities. The results extend observations of RAN effects on reading deficits to Italian, an orthographically shallow language.

Kindergarten risk factors, cognitive factors, and teacher judgments as predictors of early reading in Dutch

This study focused on the predictive value of risk factors, cognitive factors, and teachers' judgments in a sample of 462 kindergartners for their early reading skills and reading failure at the beginning of Grade 1. With respect to risk factors, enrollment in speech-language therapy, history of dyslexia or speech-language problems in the family, and the role of gender were considered. None of these risk factors were significantly related to reading performance. Cognitive factors in this study included letter knowledge, rapid naming ability, and nonword repetition skills. Of these skills, letter knowledge seemed to have the highest correlation with reading. Kindergarten teachers' judgments, including a task assignment scale and teachers' predictions, demonstrated a significant relationship with reading. Finally, to judge whether these predictors could identify reading disabilities, the discriminatory power of all predictors was assessed and appeared to be insufficient. Implications for screening purposes are discussed.

Testing the double-deficit hypothesis in an adult sample

The double-deficit hypothesis of dyslexia posits that reading deficits are more severe in individuals with weaknesses in phonological awareness and rapid naming than in individuals with deficits in only one of these reading composite skills. In this study, the hypothesis was tested in an adult sample as a model of reading achievement. Participants were parents of children referred for evaluation of reading difficulties. Approximately half of all participants reported difficulty learning to read in childhood and a small subset demonstrated ongoing weaknesses in reading. Structural equation modeling results suggest that the double-deficit hypothesis is an accurate model for understanding adult reading achievement. Better reading achievement was associated with better phonological awareness and faster rapid automatized naming in adults. Posthoc analyses indicated that individuals with double deficits had significantly lower reading achievement than individuals with single deficits or no deficits.