Past-tense morphology and phonological deficits in children with dyslexia and children with language impairment

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.

Promoting Reading Achievement in Children With Developmental Language Disorders: What Can We Learn From Research on Specific Language Impairment and Dyslexia?

Purpose Specific language impairment (SLI; see also developmental language disorder) and dyslexia are separate, yet frequently co-occurring disorders that confer risks to reading comprehension and academic achievement. Until recently, most studies of one disorder had little consideration of the other, and each disorder was addressed by different practitioners. However, understanding how the two disorders relate to each other is important for advancing theories about each disorder and improving reading comprehension and academic achievement. The purpose of this clinical focus article is to integrate research on SLI and dyslexia as well as advocate for the consideration of comorbidities in future research and clinical practice. Method The first section reviews definitions as well as inclusionary and exclusionary criteria for SLI and dyslexia. The second section reviews research demonstrating that SLI and dyslexia are different disorders that often co-occur. Studies examining language, working memory, and academic achievement in children with separate versus co-occurring SLI and dyslexia are reviewed. The final section compares and contrasts school identification frameworks for children with SLI and dyslexia and considers the potential benefits of incorporating broad language skills into response to intervention (RTI) assessment frameworks. Conclusions Children with weak language skills are at a high risk of experiencing reading problems, but language difficulties are often hidden from view. Directly addressing language skills within school RTI frameworks can help improve the identification and treatment of children with SLI and dyslexia as well as support improved reading comprehension and academic achievement for all students. Presentation Video https://doi.org/10.23641/asha.13063793.

Morphological processing influences on dyslexia in Greek-speaking children

The study explored the inflectional morphological awareness of Greek-speaking children with dyslexia in grade 3. The sample consisted of 24 dyslexic children and 32 chronological age-matched typically developing readers. All participants completed two oral experimental tasks of inflectional morphological awareness (i.e., verb inflections and noun-adjective inflections). The noun-adjective inflection task assessed children's ability to produce the plural of articles, adjectives, and nouns in the context of a sentence. The verb inflection task required children to change the tense of the verb in a sentence. Furthermore, phonological awareness and oral receptive vocabulary were assessed. Greek-speaking children with dyslexia faced difficulties in both inflectional tasks and in receptive vocabulary. They appeared to have greater difficulty in elicitation of non-past tense from past tense. Binary logistic regression targeted at understanding whether dyslexia can be predicted based on phonological and non-phonological oral language skills revealed that phonological awareness had a significant effect on distinguishing dyslexics from typically developing readers. Overall, our findings lead us to suggest that in an alphabetic language with a shallow orthographic system and rich morphology, children with dyslexia appear to have impaired inflectional morphological awareness and impaired vocabulary in comparison to their peers. Moreover, these results suggest the significance of teaching morphological skills in improving reading skills. However, further research is needed to substantiate these findings.

Stability of core language skill from infancy to adolescence in typical and atypical development

Command of language is a fundamental life skill, a cornerstone of cognitive and socioemotional development, and a necessary ingredient for successful functioning in society. We used 15-year prospective longitudinal data from the Avon Longitudinal Study of Parents and Children to evaluate two types of stability of core language skill in 5036 typically developing and 1056 atypically developing (preterm, dyslexic, autistic, and hearing impaired) children in a multiage, multidomain, multimeasure, multireporter framework. A single core language skill was extracted from multiple measures at multiple ages, and this skill proved stable from infancy to adolescence in all groups, even accounting for child nonverbal intelligence and sociability and maternal age and education. Language skill is a highly conserved and robust individual-differences characteristic. Lagging language skills, a risk factor in child development, would profitably be addressed early in life.

Developmental dyslexia and specific language impairment: distinct syntactic profiles?

Recent work exploring syntax in developmental dyslexia (DD) has identified morphosyntactic deficits, striking parallelisms between children with DD and specific language impairment (SLI). The question remains open if the underlying causes for such deficits are related to difficulties in phonology, which is affected in DD, or to working memory, as has been previously reported for SLI. We focus on the production of third person accusative clitic pronouns (ACC3) and of homophonous definite determiners in French-speaking children with DD and SLI as well as typically developing (TD) controls. If syntactic complexity modulates performance of DD children, as has already been shown for SLI, we predict children with DD to perform significantly worse on ACC3 compared to definite determiners, which are homophonous but syntactically simpler. In addition, if impairment in ACC3 stems from phonology or working memory difficulties, we expect ACC3 performance in both clinical groups to relate to performance on non-word repetition or forward/backward digit spans. We studied 2 groups of 21 children and adolescents, with DD and SLI (7-15 years) and age-matched TD controls. Results reveal significant weaknesses with ACC3 in DD and SLI groups compared to TD controls, but no difficulty for homophonous definite determiners, confirming a deficit relating specifically to syntactic complexity. As for links to phonology and working memory, a single correlation emerged between ACC3 and the backward digit span in SLI, but not in DD, suggesting different underlying sources for syntactic deficits in these populations. Clinical implications of these results are discussed.

Spelling and Morphology in Dyslexia: A Developmental Study Across the School Years

The current study examined the effect of morphological knowledge on spelling development in Hebrew-speaking schoolchildren, adolescents and adults with dyslexia, compared with typically developing (TD) peers. Participants were 238 Hebrew-speaking readers of five grade levels of whom 139 were TD and 99 had developmental dyslexia (DD). Participants were tested on a function letter spelling task, a phonological awareness task and a morphological awareness task. The overall picture that emerged from the results is that performance on all measures increased with grade level, with TD participants always scoring higher than peers with DD. Moreover, the higher the morphological complexity in spelling and irregularity in noun inflection, the higher the differences between the DD and TD participants. Finally, performance on the morphological awareness task contributed to spelling morphologically more complex spelling items in the TD, but not in the DD group. From clinical and educational perspectives, these results strongly suggest that rigorous morphological instruction is necessary in teaching children and adolescents with dyslexia to identify and use morphological cues in spoken and written Hebrew. Copyright © 2017 John Wiley & Sons, Ltd.