Non-word repetition and literacy in Dutch children at-risk of dyslexia and children with SLI: results of the follow-up study

The contribution of individual differences in statistical learning to reading and spelling performance in children with and without dyslexia

Using an individual differences approach in children with and without dyslexia, this study investigated the hypothesized relationship between statistical learning ability and literacy (reading and spelling) skills. We examined the clinical relevance of statistical learning (serial reaction time and visual statistical learning tasks) by controlling for potential confounds at the participant level (e.g., non-verbal reasoning, attention and phonological skills including rapid automatized naming and phonological short-term memory). A 100 Dutch-speaking 8- to 11-year-old children with and without dyslexia participated (50 per group), see also van Witteloostuijn et al. (2019) for a study with the same participants. No evidence of a relationship between statistical learning and literacy skills is found above and beyond participant-level variables. Suggestions from the literature that the link between statistical learning and literacy attainment, and therefore its clinical relevance, might be small and strongly influenced by methodological differences between studies are not contradicted by our findings.

Do dyslexia and stuttering share a processing deficit?

This study assessed the prevalence of childhood stuttering in adults with dyslexia (AWD) and the prevalence of dyslexia in adults who stutter (AWS). In addition, the linguistic profiles of 50 AWD, 30 AWS and 84 neurotypical adults were measured. We found that 17 out of 50 AWD (34 %) reported stuttering during childhood compared to 1 % of the neurotypical population. This was moderated by the severity of dyslexia: People with mild dyslexia showed a lower prevalence rate (15 %) of childhood stuttering than those with severe dyslexia (47 %). In addition, we observed that 50 % of the AWS (n = 30) fulfilled the diagnostic criteria of dyslexia, even though they had never been diagnosed as dyslexic. Compared to neurotypical adults, phonological working memory, awareness, and retrieval were similarly reduced in AWS and AWD. The findings supports the view that stuttering and dyslexia may share a phonological deficit.

Do Children Classified With Specific Language Impairment Have a Learning Disability in Writing? A Meta-Analysis

In this meta-analysis, we examined whether children classified with specific language impairment (SLI) experience difficulties with writing. We included studies comparing children with SLI to (a) typically developing peers matched on age (k = 39 studies) and (b) typically developing younger peers with similar language capabilities (k = six studies). Children classified with SLI scored lower on writing measures than their typically developing peers matched on age (g = -0.97) when all writing scores in a study were included in the analysis. This same pattern occurred for specific measures of writing: quality (g = -0.92), output (g = -1.00), grammar (g = -0.68), vocabulary (g = -0.68), and spelling (g = -1.17). A moderator analysis revealed that differences in the writing scores of children classified with SLI and typically developing peers matched on age were not as large, but were still statistically significant, when assessment involved a contrived response format (vs. measured based on students' writing), researcher-created measures (vs. norm-referenced tests), or SLI included just children with a speech disorder (vs. children with a language disorder). Children classified with SLI further scored lower on writing than typically developing peers with similar language capabilities (g = -0.47). We concluded that children with SLI experience difficulties with writing.

Language, literacy and cognitive skills of young adults with developmental language disorder (DLD)

BACKGROUND

There is limited evidence concerning the longer term language, literacy and cognitive skills of young adults with developmental language disorder (DLD). Studies that exist suggest continuing difficulties with language and reading, but abilities may change over time.

AIMS

This study aimed to examine the language, literacy and cognitive skills of young adults with and without DLD.

METHODS & PROCEDURES

Data were used from the Manchester Language Study data set which was collected from a group of young adults with DLD (recruited originally at 7 years of age from language units-specialist educational resource bases). Participants were assessed on their language, literacy and cognitive functioning when they were aged 24. A comparison group of age-matched peers (AMPs; also 24 years old) were also assessed. For language and cognition, change in scores between 16 and 24 years was also available for analysis. Finally, self-rated measures of literacy difficulties were taken at 24 years for functional reading and writing.

OUTCOME & RESULTS

The results indicate that the young people with DLD in this sample continue to perform more poorly as a group on formal oral and written language tests. A small but significant minority of young adults with DLD also report functional reading and writing difficulties compared with AMPs despite reporting reading as often as their peer group. Compared with scores at 16 years of age, this subsample now appears to show slightly less risk of non-verbal IQ difficulties, showing small but significant 'catch-up' to AMPs.

CONCLUSIONS & IMPLICATIONS

These preliminary data suggest that at least some individuals with DLD experience marked linguistic difficulties in adulthood, and that the pathways of language, literacy and cognition are not entirely parallel for this group. Continued support and awareness of challenges for young adults with DLD may be useful. What this paper adds What is already known on the subject It is known that DLD is long term and persists into adulthood. There has recently been a body of work reporting on the well-being of this population, as well as their employment, financial status and driving ability. However, there is very little information about language, literacy and cognitive skills beyond school age. What this paper adds to existing knowledge This study presents data on language, literacy and cognition from a large cohort of young adults with DLD and their AMPs. In this sample, a large proportion of participants score low on language, with fewer scoring as impaired on literacy and cognition. A significant minority reports difficulties in functional reading. Preliminary analysis appears to suggest that while language development remains depressed, non-verbal cognitive skills show some catch up over time. What are the potential or actual clinical implications of this work? Increased awareness and continued support for language, literacy and cognition may be useful for young adults with DLD.

Reading outcomes in children with developmental language disorder: A person-centered approach

BACKGROUND AND AIMS

Many children with Developmental Language Disorder (DLD) develop reading difficulties. The purpose of this study is to better understand variation in the reading outcomes of children with DLD using a person-centered approach.

METHOD

87 monolingual Dutch children diagnosed with DLD performed at ages 5 or 6 years nine tests of nonverbal IQ, oral language proficiency, phonological memory (PM) and executive functioning (EF). Two years later, the same children were tested on single (non-)word reading. Latent profile analyses were conducted to identify profiles based on oral language proficiency, phonological memory and executive functioning at age 5-6 years, which, in turn, were related to nonverbal IQ and to single-word reading two years later.

RESULTS

Four profiles were identified and labelled relative to their position within the DLD-sample: 1. Weak performance overall, 2. Strong EF-average language and PM, 3. Mild working memory (WM) deficiencies-average language and PM, 4. Strong development overall. Profiles 1 and 3 had below average nonverbal IQ scores and were associated with low word reading outcomes two years later.

CONCLUSIONS

Within the group of children with DLD, children with relatively weak oral language, phonological memory and executive functioning, or children with working memory deficiencies are most at risk for developing reading difficulties. The findings support a multiple risk framework and confirm that a person-centered approach is promising in predicting reading outcomes in DLD.Implications: Research into individual differences in DLD is dominated by variable-centered approaches. This study illustrates how a person-centered approach, which views variables as properties of individuals, captures variation in the DLD-population. Using this bottom-up approach, the study highlights how an individual's strengths and weaknesses across different developmental domains can be combined into profiles that relate to later reading outcomes. As such, it can provide an example for future DLD research.

Shortened Nonword Repetition Task (NWR-S): A Simple, Quick, and Less Expensive Outcome to Identify Children With Combined Specific Language and Reading Impairment

PURPOSE

The purpose of this research note was to validate a simplified version of the Dutch nonword repetition task (NWR; Rispens & Baker, 2012). The NWR was shortened and scoring was transformed to correct/incorrect nonwords, resulting in the shortened NWR (NWR-S).

METHOD

NWR-S and NWR performance were compared in the previously published data set of Rispens and Baker (2012; N = 88), who compared NWR performance in 5 participant groups: specific language impairment (SLI), reading impairment (RI), both SLI and RI, one control group matched on chronological age, and one control group matched on language age.

RESULTS

Analyses of variance showed that children with SLI + RI performed significantly worse than other participant groups in NWR-S, just as in NWR. Logistic regression analyses showed that both tasks can predict an SLI + RI outcome. NWR-S holds a sensitivity of 82.6% and a specificity of 95.4% in identifying children with SLI + RI. The sensitivity of the original NWR is 87.0% with a specificity of 87.7%.

CONCLUSIONS

As the original NWR, the NWR-S comprising a subset of 22 nonwords scored with a simplified scoring system can identify children with combined SLI and RI while saving a significant amount of the needed assessment time.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5150116.

The Role of Categorical Speech Perception and Phonological Processing in Familial Risk Children With and Without Dyslexia

PURPOSE

This study assessed whether a categorical speech perception (CP) deficit is associated with dyslexia or familial risk for dyslexia, by exploring a possible cascading relation from speech perception to phonology to reading and by identifying whether speech perception distinguishes familial risk (FR) children with dyslexia (FRD) from those without dyslexia (FRND).

METHOD

Data were collected from 9-year-old FRD (n = 37) and FRND (n = 41) children and age-matched controls (n = 49) on CP identification and discrimination and on the phonological processing measures rapid automatized naming, phoneme awareness, and nonword repetition.

RESULTS

The FRD group performed more poorly on CP than the FRND and control groups. Findings on phonological processing align with the literature in that (a) phonological processing related to reading and (b) the FRD group showed the lowest phonological processing outcomes. Furthermore, CP correlated weakly with reading, but this relationship was fully mediated by rapid automatized naming.

CONCLUSION

Although CP phonological skills are related to dyslexia, there was no strong evidence for a cascade from CP to phonology to reading. Deficits in CP at the behavioral level are not directly associated with dyslexia.

Dichotic listening as an index of lateralization of speech perception in familial risk children with and without dyslexia

Atypical language lateralization has been marked as one of the factors that may contribute to the development of dyslexia. Indeed, atypical lateralization of linguistic functions such as speech processing in dyslexia has been demonstrated using neuroimaging studies, but also using the behavioral dichotic listening (DL) method. However, so far, DL results have been mixed. The current study assesses lateralization of speech processing by using DL in a sample of children at familial risk (FR) for dyslexia. In order to determine whether atypical lateralization of speech processing relates to reading ability, or is a correlate of being at familial risk, the current study compares the laterality index of FR children who did and did not become dyslexic, and a control group of readers without dyslexia. DL was tested in 3rd grade and in 5/6th grade. Results indicate that at both time points, all three groups have a right ear advantage, indicative of more pronounced left-hemispheric processing. However, the FR-dyslexic children are less good at reporting from the left ear than controls and FR-nondyslexic children. This impediment relates to reading fluency.

Oral language deficits in familial dyslexia: A meta-analysis and review

This article reviews 95 publications (based on 21 independent samples) that have examined children at family risk of reading disorders. We report that children at family risk of dyslexia experience delayed language development as infants and toddlers. In the preschool period, they have significant difficulties in phonological processes as well as with broader language skills and in acquiring the foundations of decoding skill (letter knowledge, phonological awareness and rapid automatized naming [RAN]). Findings are mixed with regard to auditory and visual perception: they do not appear subject to slow motor development, but lack of control for comorbidities confounds interpretation. Longitudinal studies of outcomes show that children at family risk who go on to fulfil criteria for dyslexia have more severe impairments in preschool language than those who are defined as normal readers, but the latter group do less well than controls. Similarly at school age, family risk of dyslexia is associated with significantly poor phonological awareness and literacy skills. Although there is no strong evidence that children at family risk are brought up in an environment that differs significantly from that of controls, their parents tend to have lower educational levels and read less frequently to themselves. Together, the findings suggest that a phonological processing deficit can be conceptualized as an endophenotype of dyslexia that increases the continuous risk of reading difficulties; in turn its impact may be moderated by protective factors. (PsycINFO Database Record

Development of reading and phonological skills of children at family risk for dyslexia: a longitudinal analysis from kindergarten to sixth grade

The main focus of this article is to develop a better understanding of the developmental trajectories of literacy and phonological skills within Dutch-speaking children. Children at high and low risk for dyslexia were followed and compared at four different moments: kindergarten and first, third and sixth grades. Three groups were then compared: (1) dyslexic readers; (2) normal readers at high risk for dyslexia; and (3) normal readers at low risk for dyslexia. Children diagnosed with dyslexia scored lower than high-risk normal readers on phonological awareness (PA), rapid automatized naming (RAN), verbal short-term memory and literacy skills. Normal readers at high risk scored between both groups, confirming that dyslexia is to be considered as a continuum rather than an all-or-none condition. Growth analyses showed that the three groups evolved similarly on all measures except for phoneme deletion and literacy measures. Finally, solely PA and RAN explained a significant amount of variance in the evolution of reading skills.

Predictors of reading in Urdu: does deep orthography have an impact?

The aim of this study was to establish the extent to which rapid automatized naming (RAN) and non-word repetition (NWR) tasks predict reading fluency and reading accuracy in Urdu. One hundred sixty (8-9 years) children attending two types of schools (Urdu and English medium schools) were distributed into two groups, a control and a reading disability group on the basis of teacher's report. The results confirmed the role of RAN in predicting reading fluency in both groups. The role of NWR as a predictor of accuracy was also confirmed, although the strength of the relationship was modulated by RAN in the reading disability group. There are no tests available to identify children with reading problems in Urdu. Our study supports the validity of NWR and RAN tasks for the purposes of screening for reading deficits. The performance results also confirm the original grouping based on teacher reports. The study further highlights the importance of medium of instruction and increased oral language input in learning to read.

Precursors of developmental dyslexia: an overview of the longitudinal Dutch Dyslexia Programme study

Converging evidence suggests that developmental dyslexia is a neurobiological disorder, characterized by deficits in the auditory, visual, and linguistic domains. In the longitudinal project of the Dutch Dyslexia Programme, 180 children with a familial risk of dyslexia (FR) and a comparison group of 120 children without FR (noFR) were followed from the age of 2 months up to 9 years. Children were assessed on (1) auditory, speech, and visual event-related potentials every half year between 2 and 41 months; (2) expressive and receptive language, motor development, behaviour problems, and home-literacy environment by questionnaires at the age of 2 and 3; (3) speech-language and cognitive development from 47 months onwards; and (4) preliteracy and subskills of reading, and reading development during kindergarten and Grades 2 and 3. With regard to precursors of reading disability, first analyses showed specific differences between FR and noFR children in neurophysiological, cognitive, and early language measures. Once reading tests administered from age 7 to 9 years were available, the children were divided into three groups: FR children with and without dyslexia, and controls. Analyses of the differences between reading groups yielded distinct profiles and developmental trajectories. On early speech and visual processing, and several cognitive measures, performance of the non-dyslexic FR group differed from the dyslexic FR group and controls, indicating continuity of the influence of familial risk. Parental reading and rapid naming skills appeared to indicate their offspring's degree of familial risk. Furthermore, on rapid naming and nonverbal IQ, the non-dyslexic FR group performed similarly to the controls, suggesting protective factors. There are indications of differences between the FR and control groups, irrespective of reading outcome. These results contribute to the distinction between the deficits correlated to dyslexia as a manifest reading disorder and deficits correlated to familial risk only.

A comparative study on diadochokinetic skill of dyslexic, stuttering, and normal children

Objective. Previous studies have shown some motor deficits among stuttering and dyslexic children. While motor deficits in speech articulation of the stuttering children are among the controversial topics, no study on motor deficits of dyslexic children has been documented to date. Methods. 120 children (40 stuttering, 40 dyslexia, and 40 normal) 6–11 years old were matched and compared in terms of diadochokinetic skill. Dyslexia symptoms checklist, reading test, and diadochokinetic task were used as measurement instruments. Results. The data analysis showed that there are significant differences (P < 0.001) in reaction time and the number of syllables in accomplishing diadochokinetic tasks among stuttering children, dyslexics, and the control group. This indicates that stuttering children and dyslexics have poor performance in reaction time and in the number of monosyllable articulation and long syllable articulation. Furthermore, there are significant differences (P < 0.001) in these indices between stuttering children and dyslexics, so that the latter group have better performance than the former one. Conclusion. The findings indicate that stuttering children and dyslexics have deficits in diadochokinetic skill which suggests their low performance in the motor control of speech production and articulation. Such deficits might be due to the role of the tongue in the development of stuttering and dyslexia.

Non-adjacent dependency learning in infants at familial risk of dyslexia

This study tests the hypothesis that developmental dyslexia is (partly) caused by a deficit in implicit sequential learning, by investigating whether infants at familial risk of dyslexia can track non-adjacent dependencies in an artificial language. An implicit learning deficit would hinder detection of such dependencies, which mark grammatical relations (e.g. between 'is' and '-ing' in 'she is happily singing'). In a head-turn experiment with infants aged 1;6, family risk and typically developing infants were exposed to one of two novel languages containing dependencies of the type a-X-c, b-X-d or a-X-d, b-X-c, with fixed first and third elements and twenty-four different X elements. During test, typically developing children listened longer to ungrammatical strings (i.e. that did not correspond to their training language). However, family-risk children did not discriminate between grammatical and ungrammatical strings, indicating deficient implicit learning. The implications of these findings in relation to dyslexia and other language-based disorders are discussed.

Development of phonological processing skills in children with specific language impairment with and without literacy delay: a 3-year longitudinal study

PURPOSE

To compare the development of phonological skills in children with specific language impairment (SLI) with and without literacy delay and to examine whether kindergarten phonological skills could discriminate these 2 groups.

METHOD

In a longitudinal study, 8 children with SLI and literacy delay, 10 children with SLI and normal literacy, and 14 typically developing children were studied from the last year of kindergarten to the start of Grade 3. A wide range of phonological tasks (phonological awareness [PA], verbal short-term memory [vSTM], and rapid automatized naming [RAN]) were administered yearly.

RESULTS

The SLI group with literacy delay scored significantly lower than the typically developing children on almost all phonological tasks in all grades, whereas the SLI group with normal literacy scored significantly lower only on demanding PA and vSTM tasks. A combination of kindergarten PA and RAN skills could correctly classify 75% of the children with SLI. By including vSTM, the discriminatory value did not increase.

CONCLUSIONS

Children with SLI and normal literacy at age 8;1 [years;months] continued to have difficulties with demanding PA and vSTM tasks. Children with SLI and poor PA and RAN in kindergarten were at high risk of developing literacy problems in a transparent orthography.

Nonword repetition: the relative contributions of phonological short-term memory and phonological representations in children with language and reading impairment

PURPOSE

This study investigates the relative contributions of phonological short-term memory and phonological representations to nonword repetition (NWR). This was evaluated in children with specific language impairment (SLI) and/or reading impairment (RI); it was also studied from a developmental perspective by comparing 2 groups of typically developing (TD) children who differed in age.

METHOD

NWR, digit span, vocabulary, and word and nonword discrimination were tested in 2 groups of TD children: one group matched on chronological age (CA TD group: n = 41, mean age = 7;8 [months;years]), and one language age-matched control group (LA TD group: n = 16, mean age = 5;8). Also, 10 children with SLI, 14 children with RI, and 23 children with SLI and RI (hereafter, SLI + RI) participated and were matched to the age of the CA TD group.

RESULTS

For the TD children, NWR was predicted by discrimination, digit span, and age. The interaction between discrimination ability and age was also significant. Children with SLI + RI were significantly impaired on NWR compared with all other groups. A regression analysis, including the CA TD group and the children with SLI and/or RI, showed that digit span, discrimination ability, and group (SLI + RI) contributed significantly to NWR.

CONCLUSIONS

Phonological short-term memory and phonological representations both significantly contribute to NWR. The predictive strength of the quality of phonological representations changes during development.

Non-word repetition in adolescents with specific language impairment (SLI)

BACKGROUND

Non-word repetition (NWR) difficulties are common, but not universal, among children with specific language impairment (SLI). However, older children and adolescents with SLI have rarely been studied. Studies disagree on the relationship between NWR difficulties and difficulties with other areas of language and literacy. There is also no consensus about the underlying reason for the difficulties (some) children with SLI have with NWR. Some scholars argue that difficulties with phonological short-term memory or storage cause NWR and other language difficulties, whereas others argue that difficulties with NWR may be due more to difficulties with phonological representations.

AIMS

To investigate NWR abilities and their relationship to other language and literacy abilities in a group of older children with SLI and typically developing controls. To investigate the relative effects of increasing phonological complexity and the number of syllables on the ability of the participants to repeat non-words.

METHODS & PROCEDURES

An NWR test (The Test of Phonological Structure; TOPhS), which systematically varies phonological complexity, was administered to 15 participants with SLI (aged 11-15 years), 30 language and 15 age controls. Standardized language and literacy tests and a specific test of verb agreement and tense marking (Verb Agreement and Tense Test; VATT) were also administered.

OUTCOMES & RESULTS

The participants with SLI showed a bimodal distribution: half achieved age-appropriate NWR, while half scored significantly below language and age controls (d > 7). The two groups of participants with SLI (high versus low scorers) only differed in NWR (d > 5) and agreement (d > 3) and tense marking (d > 2.5), not on the standardized language and literacy measures administered. NWR was also highly correlated with verb agreement (r= 0.97) and tense marking (r= 0.89) among participants with SLI, but not among controls (r= 0.16 and 0.30 respectively). Phonological complexity was related to NWR accuracy, particularly among participants with SLI. The number of syllables had no independent effect on NWR performance for any group.

CONCLUSIONS & IMPLICATIONS

Some children with SLI (who have good NWR) have language difficulties unrelated to any of the factors underlying NWR. Others have a (probably additional) deficit which affects NWR and also leads to greater difficulties with verb agreement and tense marking. The results indicate that difficulties with this particular NWR test are more likely to be due to a deficit with phonology per se, rather than with phonological short-term memory or storage.

Child and parental literacy levels within families with a history of dyslexia

BACKGROUND

The present study concerns literacy and its underlying cognitive skills in Dutch children who differ in familial risk (FR) for dyslexia. Previous studies with FR-children were inconclusive regarding the performance of FR-children without dyslexia as compared to the controls. Moreover, van Bergen et al. (2011) recently showed that FR-children with and without dyslexia differed in parental reading skills, suggesting that those who go on to develop dyslexia have a higher liability. The current study concerned 1) the comparison of three groups of children at the end of second grade and 2) the intergenerational transfer of reading and its underlying cognitive skills from parent to child.

METHOD

Three groups of children were studied at the end of second grade: FR-dyslexia (n = 42), FR-no-dyslexia (n = 99), and control children (n = 66). Parents and children were measured on naming, phonology, spelling, and word and pseudoword reading.

RESULTS

The FR-dyslexia children were severely impaired across all tasks. The FR-no-dyslexia children performed better than the FR-dyslexia children, but still below the level of the controls on all tasks; the only exception was rapid naming (RAN), on which they were as fast as the controls. Focusing on the FR subsample, parental reading and RAN were related to their offspring's reading status.

CONCLUSIONS

We replicated and extended van Bergen et al.'s study in showing that the FR-children who develop dyslexia are likely to have a higher liability. Both the group comparisons and the parent-child relations highlight the importance of good RAN skills for reading acquisition.

Assessing component language deficits in the early detection of reading difficulty risk

This article focuses on some of the linguistic components that underlie letter-sound decoding skills and reading comprehension: specifically phonology, morphology, and syntax. Many children who have reading difficulties had language deficits that were detectable before they began reading. Early identification of language difficulties will therefore help identify children at risk of reading failure. Using a developmental psycholinguistic framework, the authors provide a model of how syntax, morphology, and phonology break down in children with language impairments. The article reports on a screening test of these language abilities for preschool or young school-aged children that identifies those at risk for literacy problems and in need of further assessment.

Towards a further characterization of phonological and literacy problems in Dutch-speaking children with dyslexia

This longitudinal study examined the development of phonology and literacy in Dutch-speaking children at family risk of dyslexia and in matched controls. Measures were administered in kindergarten (before the start of formal reading instruction), in first and in third grade. Children, diagnosed with dyslexia in third grade, showed impaired phonological awareness (PA), verbal short-term memory, and rapid automatic naming ability (RAN) at all time points, with the deficit in PA aggravating over time. These children also performed more poorly in letter knowledge, word and nonword reading accuracy and speed, and spelling at each time point. Children at family risk of dyslexia who did not fulfil criteria for dyslexia, scored more poorly than low-risk controls on the literacy and phonological measures that required the most fine-grained phonological representations. This suggests that the family risk of dyslexia is continuous rather than discrete. Hierarchical regression analyses demonstrated that PA and RAN were initially the most important instigators of reading accuracy and reading speed, respectively. After 2 years of reading instruction, only RAN predicted reading speed and accuracy. Letter knowledge, reading accuracy, and reading speed also contributed to the development of PA.