Phonological and lexical influences on phonological awareness in children with specific language impairment and dyslexia

Reading skills over time among children with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked progressive neuromuscular disorder with a distinct cognitive profile including decreased verbal span. Children with DMD are also at risk for lower scores on academic achievement tests and increased behavioral problems. Longitudinal analyses generally reveal a stable intellectual profile, although attention and behavioral problems may negatively impact longitudinal IQ scores. To date, no study has reported on reading over time in DMD. Reading performance was assessed longitudinally in children with DMD, examining for potential contributions to the trajectory. Retrospective data analysis on assessments completed at baseline, year 2, and year 4 on 26 boys with DMD and 27 unaffected sibling controls (age at baseline: DMD 8 ± 1.4, controls 9 ± 2.6) indicated that children with DMD performed slightly, yet significantly, worse than controls on reading skills, but the longitudinal trajectory of reading skills for children with DMD and controls was not significantly different. Verbal span at time 1 was uniquely associated with later reading skills in children with DMD. Behavior was not associated with declines. The results confirm that children with DMD underperform on reading tasks and align with previous research suggesting that cognitive skills in DMD are stable over time.

Dyslexia and Stuttering: An Overview of Processing Deficits and the Relationship Between Them

Stuttering and dyslexia are two processing deficits that have an impact on a person's social and academic lives, especially as they usually affect the pediatric population more than adults. Even though they affect different domains, they have similar characteristics in their pathogenesis, epidemiology, and impact on life. Both disorders represent a considerable percentage of the population worldwide and locally in Saudi Arabia, and they have similar epidemiological trends. Family history, genetic factors, early fetal and neonatal factors, and environmental factors are all identified as risk factors for both conditions. Moreover, it has been established that both diseases share a common genetic and anatomical basis, along with a mutual disruption of diadochokinetic skills. While rehabilitative techniques can be used in both conditions, stuttering could also benefit from pharmacological interventions. This review emphasizes that extensive research should be done to explore both of these conditions as they impact different areas of one's life and the relationship between them to better understand their pathophysiological origins.

A web-based interface to calculate phonological neighborhood density for words and nonwords in Modern Standard Arabic

The availability of online databases (e.g., Balota et al., 2007) and calculators (e.g., Storkel & Hoover, 2010) has contributed to an increase in psycholinguistic-related research, to the development of evidence-based treatments in clinical settings, and to scientifically supported training programs in the language classroom. The benefit of online language resources is limited by the fact that the majority of such resources provide information only for the English language (Vitevitch, Chan & Goldstein, 2014). To address the lack of diversity in these resources for languages that differ phonologically and morphologically from English, the present article describes an online database to compute phonological neighborhood density (i.e., the number of words that sound similar to a given word) for words and nonwords in Modern Standard Arabic (MSA). A full description of how the calculator can be used is provided. It can be freely accessed at https://calculator.ku.edu/density/about .

Phonological awareness in children with developmental language disorder

Children with developmetal language disorder have impaired developmental pattern of language structure. Literature data speak in favor of delay and/or difficulties in development of phonological, lexical, morphological and syntactic structure, but the nature of developmental language disorder (DLD) has still not been elucidated. The aim of this paper was to present and analyze data about phonological awareness in children with DLD based on a systematic literature review. Also, we wanted to point out some methods of assessment and stimuli/encouragement in development of phonological abilities. The research presented in the analyzed literature have shown that current knowledge regarding phonological awareness in children with DLD is mainly obtained from comparative stuides of children with developmental language disorder and children with normal language development. A large number of results has revealed that different components of phonological awareness in children with DLD are less developed compared to their peers with typical development. Studies have also presented current assessment techniques and importance of phonological awareness preventive stimulation progams, which are an important indicator/parameter for the development of reading and writing as well as for onset of impairments in learning these skills.

Predicting dyslexia in Arabic-speaking children: Developing instruments and estimating their psychometric indices

Dyslexia is a reading disability that is characterized by when an individual has trouble in rapid and accurate word decoding. This study developed, piloted and assessed the validity and reliability of three instruments: Rapid Automatized Scale (RANS), Arabic Reading Ability Scale (ARAS) and Phonological Awareness Scale (PAS), on a sample of 700 students (aged 8-9 years). Four groups (n = 30) were formed based on the participants' results of the three instruments; Double Deficit (DD), Rapid Automatized Naming Deficit (RAND), Phonological Awareness Deficit (PAD) and No Deficit groups. Content validities of the instruments were supported using published reports; though educational experts further revised RANS. It found a significant inverse correlation between the PA test score and RAN (mistakes and time) score (r = -.44; p < .001), and a significant positive correlation between RAN mistakes and RAN time (r = .47; p < .001). Acceptable internal reliability of the RANS was demonstrated by a Cronbach's alpha test coefficient of α = .85 (>.70; acceptable). High inter-rater reliability tests were observed for the three instruments (r ≥ .86, p < .001). The three instruments can predict reading difficulties and dyslexia in Arabic-speaking populations.

The relationship between developmental language disorder and dyslexia in European Portuguese school-aged children

Developmental Language Disorder (DLD) [Also referred to as Specific Language Impairment (SLI)] and dyslexia are neurodevelopmental disorders which show similar behavioral manifestations. In this study, between-group comparisons and frequency analysis were combined to investigate the relationship between DLD and dyslexia. European Portuguese children aged 7-10 years, with DLD (N = 7) or dyslexia (N = 11) were recruited and compared to age-matched typically developing (TD) children (N = 21) on phonological processing, language andf literacy measures. The between-group comparison revealed that for phonological processing, the clinical groups scored significantly below TD children on most tasks, yet the DLD group performed similarly to TD children for RAN speed and digit span. The clinical groups did not statistically differ in their phonological processing abilities. For language abilities, children with dyslexia did not differ from TD children, whilst children with DLD performed significantly below TD children on all measures and significantly below children with dyslexia for vocabulary. Finally, for literacy measures, there were no statistical differences between clinical groups which underperformed on all measures when compared to TD children. The frequency analysis showed that children with DLD exhibited a lower prevalence of RAN difficulties when compared to children with dyslexia, whilst children with DLD tended to show more frequent nonword repetition and phoneme deletion deficits. Additionally, whilst children with DLD consistently showed more prevalent language impairments, both clinical groups demonstrated similar prevalence rates of literacy deficits compared to TD children.These findings lend support to the additional deficit model as children with DLD show more severe and prevalent language impairments than those with dyslexia, despite similar phonological and literacy difficulties.

The Relation Between Vocabulary Knowledge and Phonological Awareness in Children With Cochlear Implants

Purpose The purpose of this study was to evaluate the relation between lexical knowledge and phonological awareness performance of children with cochlear implants. Method Thirty children with cochlear implants (aged 5-7 years), 30 children with normal hearing matched for age, and 30 children with normal hearing matched for vocabulary size participated in the study. Children completed a vocabulary knowledge measure and three phonological awareness tasks with words that had high and low neighborhood density. Results Children with cochlear implants performed more poorly than their age-matched peers and similarly to their vocabulary-matched peers on phonological awareness tasks. When performance was analyzed according to the neighborhood density of the target word, children with cochlear implants and age-matched children performed better with high-density words. Across all groups, vocabulary size correlated significantly with phonological awareness performance. Conclusion Children with cochlear implants demonstrate delays in both vocabulary knowledge and phonological awareness performance, but children with cochlear implants appear to take advantage of lexical information similarly to their age-matched peers.

Relationship Between Children's Lexical Diversity in Written Narratives and Performance on a Standardized Reading Vocabulary Measure

The purpose of this study was to examine construct validity of methods of calculating lexical diversity in written narrative samples relative to children's performance on a reading vocabulary measure. For 234 children in 1st-5th grade, written narratives were examined and compared between grades for number of different words (NDW), total words (TNW), NDW in a truncated 50 word sample, and type token ratio (TTR). The relationship between lexical diversity in written narratives and a standardized reading vocabulary measure (GMRT-4) was analyzed by comparing correlations. Grade differences were observed in measures of lexical diversity and productivity. Lexical diversity showed a significant moderate correlation with the GMRT-4. NDW had a stronger relationship to GMRT-4 scores than TTR for participants in first and second grade. Considering length (TNW, NDW constrained to 50 words, or TTR) did not result in a stronger relationship with reading vocabulary. Following additional study establishing probe equivalence, NDW in written narratives may be an efficient, educationally relevant, marker of language maturity and a good predictor of performance on a standardized reading vocabulary measure.

Exploring the Overlap Between Dyslexia and Speech Sound Production Deficits

Purpose

Children with dyslexia have speech production deficits in a variety of spoken language contexts. In this article, we discuss the nature of speech production errors in children with dyslexia, including those who have a history of speech sound disorder and those who do not, to familiarize speech-language pathologists with speech production-specific risk factors that may help predict or identify dyslexia in young children.

Method

In this tutorial, we discuss the role of a phonological deficit in children with dyslexia and how this may manifest as speech production errors, sometimes in conjunction with a speech sound disorder but sometimes not. We also briefly review other factors outside the realm of phonology that may alert the speech-language pathologist to possible dyslexia.

Results

Speech-language pathologists possess unique knowledge that directly contributes to the identification and remediation of children with dyslexia. We present several clinical recommendations related to speech production deficits in children with dyslexia. We also review what is known about how and when children with speech sound disorder are most at risk for dyslexia.

Conclusion

Speech-language pathologists have a unique opportunity to assist in the identification of young children who are at risk for dyslexia.

Effects of rapid automatized naming and phonological awareness deficits on the reading ability of Arabic-speaking elementary students

Dyslexia is one of the most common reading disabilities everywhere, including the United Arab Emirates (UAE). Studies have shown that rapid automatized naming (RAN) and phonological awareness (PA) are factors associated with dyslexia. Arabic is a language with unique orthographic features making it different from English and other European languages. There are limited studies of the effects of RAN and PA on reading achievement in Arabic. This article reports an investigation into the effects of RAN and PA on the reading ability of Arabic-speaking children with no reported history of intellectual, speech, language, or hearing disabilities. A cohort of 615 third-grade students at five public schools in the UAE were tested on the Arabic Reading Ability Scale (ARAS) and those with the lowest 20% of scores were then subjected to a PA test and a RAN test. Those with no RAN or PA deficit were found to achieve the highest mean Arabic reading score, followed in descending order by the RAN deficit, PA deficit and double-deficit groups. Taken together, the results confirm that phonological skills and naming-speed skills make distinct contributions to reading ability and that deficits in these two areas are particularly pronounced among individuals with dyslexia.

Auditory Lexical Decisions in Developmental Language Disorder: A Meta-Analysis of Behavioral Studies

PURPOSE

Despite the apparent primacy of syntactic deficits, children with developmental language disorder (DLD) often also evidence lexical impairments. In particular, it has been argued that this population have difficulty forming lexical representations that are detailed enough to support effective spoken word processing. In order to better understand this deficit, a meta-analysis of studies testing children with DLD in the auditory lexical decision task was conducted. The objective was to provide summary effect size estimates for accuracy and response time measures for comparisons to age- and language-matched control groups.

METHOD

Two thousand three hundred seventy-two records were initially identified through electronic searches and expert consultation, with this cohort reduced to 9 through duplicate removal and the application of eligibility and quality criteria. The final study cohort included 499 children aged 3;8-11;4 (years;months).

RESULTS

Multivariate analysis suggests that children with DLD were significantly less accurate in the auditory lexical decision task than age-matched controls. For the response time estimate, however, confidence intervals for the same group comparison crossed 0, suggesting no reliable difference between groups. Confidence intervals also crossed 0 for language-matched control estimates for both accuracy and response time, suggesting no reliable difference between groups on either measure.

CONCLUSION

Results broadly support the hypothesis that children with DLD have difficulty in forming detailed lexical representations relative to age- though not language-matched peers. However, further work is required to determine the performance profiles of potential subgroups and the impact of manipulating different lexical characteristics, such as the position and degree of nonword error, phonotactic probability, and semantic network size.

Phonological awareness development in children with and without spoken language difficulties: A 12-month longitudinal study of German-speaking pre-school children

PURPOSE

There is strong empirical evidence that English-speaking children with spoken language difficulties (SLD) often have phonological awareness (PA) deficits. The aim of this study was to explore longitudinally if this is also true of pre-school children speaking German, a language that makes extensive use of derivational morphemes which may impact on the acquisition of different PA levels.

METHOD

Thirty 4-year-old children with SLD were assessed on 11 PA subtests at three points over a 12-month period and compared with 97 four-year-old typically developing (TD) children.

RESULT

The TD-group had a mean percentage correct of over 50% for the majority of tasks (including phoneme tasks) and their PA skills developed significantly over time. In contrast, the SLD-group improved their PA performance over time on syllable and rhyme, but not on phoneme level tasks. Group comparisons revealed that children with SLD had weaker PA skills, particularly on phoneme level tasks.

CONCLUSION

The study contributes a longitudinal perspective on PA development before school entry. In line with their English-speaking peers, German-speaking children with SLD showed poorer PA skills than TD peers, indicating that the relationship between SLD and PA is similar across these two related but different languages.

Knockdown of Dyslexia-Gene Dcdc2 Interferes with Speech Sound Discrimination in Continuous Streams

Dyslexia is the most common developmental language disorder and is marked by deficits in reading and phonological awareness. One theory of dyslexia suggests that the phonological awareness deficit is due to abnormal auditory processing of speech sounds. Variants in DCDC2 and several other neural migration genes are associated with dyslexia and may contribute to auditory processing deficits. In the current study, we tested the hypothesis that RNAi suppression of Dcdc2 in rats causes abnormal cortical responses to sound and impaired speech sound discrimination. In the current study, rats were subjected in utero to RNA interference targeting of the gene Dcdc2 or a scrambled sequence. Primary auditory cortex (A1) responses were acquired from 11 rats (5 with Dcdc2 RNAi; DC-) before any behavioral training. A separate group of 8 rats (3 DC-) were trained on a variety of speech sound discrimination tasks, and auditory cortex responses were acquired following training. Dcdc2 RNAi nearly eliminated the ability of rats to identify specific speech sounds from a continuous train of speech sounds but did not impair performance during discrimination of isolated speech sounds. The neural responses to speech sounds in A1 were not degraded as a function of presentation rate before training. These results suggest that A1 is not directly involved in the impaired speech discrimination caused by Dcdc2 RNAi. This result contrasts earlier results using Kiaa0319 RNAi and suggests that different dyslexia genes may cause different deficits in the speech processing circuitry, which may explain differential responses to therapy.

SIGNIFICANCE STATEMENT

Although dyslexia is diagnosed through reading difficulty, there is a great deal of variation in the phenotypes of these individuals. The underlying neural and genetic mechanisms causing these differences are still widely debated. In the current study, we demonstrate that suppression of a candidate-dyslexia gene causes deficits on tasks of rapid stimulus processing. These animals also exhibited abnormal neural plasticity after training, which may be a mechanism for why some children with dyslexia do not respond to intervention. These results are in stark contrast to our previous work with a different candidate gene, which caused a different set of deficits. Our results shed some light on possible neural and genetic mechanisms causing heterogeneity in the dyslexic population.

Reading skills in young adolescents with a history of Specific Language Impairment: The role of early semantic capacity

This study assessed the reading skills of 19 Spanish-Catalan children with Specific Language Impairment (SLI) and 16 age-matched control children. Children with SLI have difficulties with oral language comprehension, which may affect later reading acquisition. We conducted a longitudinal study examining reading acquisition in these children between 8 and 12 years old and we relate this data with early oral language acquisition at 6 years old. Compared to the control group, the SLI group presented impaired decoding and comprehension skills at age 8, as evidenced by poor scores in all the assessed tasks. Nevertheless, only text comprehension abilities appeared to be impaired at age 12. Individual analyses confirmed the presence of comprehension deficits in most of the SLI children. Furthermore, early semantic verbal fluency at age 6 appeared to significantly predict the reading comprehension capacity of SLI participants at age 12. Our results emphasize the importance of semantic capacity at early stages of oral language development over the consolidation of reading acquisition at later stages.

LEARNING OUTCOMES

Readers will recognize the relevance of prior oral language impairment, especially semantic capacity, in children with a history of SLI as a risk factor for the development of later reading difficulties.