Reading skills and phonological awareness acquisition in Down syndrome

Study of a set of reading precursors among Chilean children with Down syndrome

Learning to read for children with Down syndrome is relevant because of the impact this ability has on learning and the development of autonomy. Previous research has described reading development in this population, but it is not clear if the process and precursors are the same in a transparent language like Spanish. This study explores performance in a set of precursors (phonological awareness, visual recognition, vocabulary, letter knowledge and verbal reasoning) in 42 children with Down syndrome between 6:0 and 10:11 years. We hypothesized that the participants would have a lower performance than previously reported with children with typical development, particularly in tasks of phonological awareness, because the method for reading instruction in Chile with this population is usually the global method. Our results show that the precursors improve with age, that there are differences in performance between the skills assessed, and the ceiling effect was not observed as would be expected for children with typical development for the abilities assessed at these ages, which suggests that in the children assessed the precursors are not consolidated at these ages. These results suggest that the stimulation of phonological awareness and other reading precursors in children with Down syndrome is important for reading development.

Spelling deficits in children with intellectual disabilities: Evidence from a regular orthography

Introduction

In individuals with intellectual disabilities (ID), efficient reading and writing skills promote social integration, self-autonomy, and independence. However, research has mainly focused on reading skills, while evidence on spelling skills is scarce and mostly on English-speaking subjects. In the present research project, we compared the spelling skills of children with intellectual disabilities (ID) learning in Italian, a regular orthography, to those of typically developing children matched for school level.

Methods

In the first study, the performance on a Passage Dictation Test of forty-four children with ID attending regular classrooms from 4th to 8th grades (mean age = 12.16 years; SD = 1.57) were compared with controls matched for sex and grade. In the second study, a Words and Nonwords Dictation Test was administered (with stimuli varying for lexicality, orthographic complexity, regularity of transcription, and the presence of different types of phonetic-phonological difficulties) to twenty-two children with ID attending regular classrooms from 4th to 8th grades (mean age = 12.2 years; SD = 1.37) and 22 controls matched for sex and grade. In both studies, an error analysis was performed to characterize types of misspellings. Separate ANOVAs were performed on z scores.

Results

Children with ID generally had a lower performance than controls. In the Passage Dictation Test, they showed a higher number of phonological (and phonetic-phonological) errors than phonologically plausible ones, indicating, as a group, predominant phonological difficulties as compared to lexical-orthographic ones. In the Words and Nonwords Dictation Test, they performed poorly on regular stimuli presenting specific types of phonetic-to-phonological difficulties (geminates, non-continuant consonants) and committed more minimal distance, context-sensitive and simple conversion misspellings. However, deficits in the orthographic-lexical procedure, as indicated by a low performance in words with unpredictable spelling, were present in a high percentage of children.

Discussion

It is concluded that children with ID have significant spelling difficulties not confined to the orthographic process but also in phoneme-to-grapheme mapping that, in a regular orthography like Italian, should be acquired early and easily.

Decoding Abilities in Adolescents with Intellectual Disabilities: The Contribution of Cognition, Language, and Home Literacy

Decoding abilities in individuals with intellectual disabilities (ID) are substantially lower than for typical readers. The underlying mechanisms of their poor reading remain uncertain. The aim of this study was to investigate the concurrent predictors of decoding ability in 136 adolescents with non-specific ID, and to evaluate the results in relation to previous findings on typical readers. The study included a broad range of cognitive and language measures as predictors of decoding ability. A LASSO regression analysis identified phonological awareness and rapid automatized naming (RAN) as the most important predictors. The predictors explained 57.73% of the variance in decoding abilities. These variables are similar to the ones found in earlier research on typically developing children, hence supporting our hypothesis of a delayed rather than a different reading profile. These results lend some support to the use of interventions and reading instructions, originally developed for typically developing children, for children and adolescents with non-specific ID.

Language profiles of Welsh-English bilingual children with Down syndrome

PURPOSE

Given that children with Down syndrome (DS) have language learning difficulties, concerns have been raised about the capacity of these children to acquire two (or more) languages. This research examines the language profiles of bilingual children with DS and typically developing (TD) children in comparison to monolinguals, with a view towards identifying the factors associated with language abilities within these populations.

METHOD

Four groups of children were recruited: Welsh-English bilinguals with DS (n=10), English monolinguals with DS (n=10), TD Welsh-English bilinguals (n=10) and TD English monolinguals (n=10). Children were individually matched on nonverbal cognitive ability (NVCA) to each child in the bilingual DS group and the four groups were matched on socioeconomic status and gender. Bilinguals were matched on current and lifetime exposure to Welsh and age of first exposure to their L2. Within DS and TD groups, chronological age was statistically controlled for. Language abilities were assessed via standardised assessments and specially designed tasks. Bilinguals were assessed in both of their languages.

RESULTS

Results show no effect of language status on measures of expressive and receptive language abilities or phonological awareness. Language impairments were evident for both DS groups, particularly for expressive morphosyntax. Welsh receptive vocabulary scores of the bilinguals with DS were comparable to the TD bilinguals. Working memory, phonological awareness and chronological age were the strongest predictors of receptive language outcomes in both DS groups, explaining 90% of the variability.

CONCLUSIONS

In conclusion, we report no adverse outcomes on language development for bilinguals with DS. To our knowledge, this is the first group study of bilingualism in children with DS within the UK. Findings align with and add to the growing body of literature that reports that bilingualism does not negatively impact the language development of children with developmental disabilities. Clinical and educational implications are discussed.

Reading Skills in Down Syndrome: Implications for Clinical Practice

Though children with Down syndrome can learn to read, they may have difficulty developing some component skills, including phonological awareness and word decoding. Given reading's foundation in language, speech-language pathologists (SLPs) should play a central role in supporting access to and providing reading instruction for children with Down syndrome. This article reviews the available research on reading in Down syndrome and offers guidance for SLPs working with this population. We start by reviewing the Down syndrome phenotype, highlighting physical features and cognitive and linguistic patterns of strength and weakness that impact reading development. Next, we define different reading subskills and outline typical reading development, including stages of prereading, learning to read, and transitioning to using reading as a tool for learning. We then use these stages to review what is known about reading in Down syndrome, including relevant intervention work. We also incorporate considerations for clinical practice. In particular, we encourage SLPs to advocate for supporting reading development in children with Down syndrome, to work with families to develop rich home literacy environments, and to work with educators to promote phonological awareness and decoding skills. Lastly, we note limitations in our current knowledge and include a call for more research.

Systematic Review of Recent Pediatric Down Syndrome Neuropsychology Literature: Considerations for Regression Assessment and Monitoring

OBJECTIVES

To conduct a systematic review of recent pediatric Down syndrome (DS) neuropsychology research that may be useful to clinicians and researchers examining regression in this population.

METHODS

We reviewed original peer-reviewed articles published between 2013 and 2018 studying neuropsychological profiles in DS.

RESULTS

Thirty-one articles (of 1231 included in the original search) passed all inclusion criteria, were evaluated for bias, and were included in the analysis.

CONCLUSION

Findings argued against a single "DS profile" and revealed multiple within-group differences as well as expected and unexpected differences relative to typically developing children and children with other intellectual and developmental disabilities. Areas identified as most germane to regression monitoring included working memory, inhibition, letter and word identification, navigational route learning, motor skills (when strong at baseline), single word receptive/expressive vocabulary, and adaptive function.

Acquisition of Reading and Intellectual Development Disorder

We propose a review of the literature of the studies investigating reading acquisition in intellectual deficiency (ID), with particular focus on the explanatory factors for reading difficulties. Indeed, we explore the role of intellectual efficiency, perceptual abilities, oral language development, phonological processing and memory. The study of reading acquisition in ID is a challenge because of a high degree of heterogeneity in the results which, together with other variables influencing learning and development. This review has allowed us to understand that there are multiple reasons why individuals with ID have difficulty learning to read. More specifically, there is a link between reading skills and certain cognitive skills, such as perception, oral language, phonological processing and working memory.

Reading Deficits in Intellectual Disability Are still an Open Question: A Narrative Review

BACKGROUND

In children with intellectual disability (ID), the acquisition of reading skills constitutes a basic step towards the possibility of independent living, social inclusion and participation.

METHODS

We carried out a narrative review of the literature on reading fluency and accuracy of individuals with ID resulting from different genetic syndromes (Fragile X, Williams, Velocardiofacial, Prader-Willi, and Down syndrome). Our aim was to define their reading profiles in light of the dual-route reading model. For this purpose, studies that examined both word and non-word reading in children with ID were included in the analysis.

RESULTS

Seventeen studies emerged based on the selection criteria. The results were different depending on the control group used. A deficit in reading non-words emerged in studies that used the reading-level match design but not when standardized scores were used, when controls were age-matched or when a mental age matching was used. Thus, a deficit in reading non-words emerged only in studies that used the reading-level match design. However, severe methodological criticisms were recently raised about the use of this matching design.

CONCLUSIONS

In view of the methodological problems in using grade equivalents, it is premature to draw definite conclusions about the reading profile of children with ID resulting from different genetic syndromes. In any case, the reviewed evidence provides little support for the idea that children with ID have selective difficulty in phonological reading. Thus, the reading profile of children with ID remains an open question that needs to be investigated by means of methodologically sound research.

Reading Skills in Down Syndrome: An Examination of Orthographic Knowledge

The primary goal of this study was to examine the word identification domain of the Simple View of Reading in participants with Down syndrome (DS) by comparing them to participants with typical development (TD) matched on word identification ability. Two subskills, phonological recoding and orthographic knowledge, were measured. Results revealed that individuals with DS performed similarly to controls on 2 measures of orthographic knowledge, but more poorly on phonological recoding and a third measure of orthographic knowledge. The first two orthographic tasks included real words as stimuli; the third task used letter patterns, not real words. These results suggest that individuals with DS may have a relative strength in word-specific orthographic knowledge but not in general orthographic knowledge.

Reading comprehension in children with Down syndrome

Two studies aimed to investigate the reading comprehension abilities of 14 readers with Down syndrome aged 6 years 8 months to 13 years relative to those of typically developing children matched on word reading ability, and to investigate how these abilities were associated with reading accuracy, listening comprehension, phonological awareness and vocabulary knowledge. Study 1 confirmed significantly poorer passage-reading comprehension than the typically developing group. In an experimental task, readers with Down syndrome understood fewer written sentences than the typical group and, contrary to prediction, received no advantage from printed sentences compared to spoken sentences, despite the lower memory load. Reading comprehension was associated with listening comprehension, word reading and phonological awareness in DS. Vocabulary knowledge was also associated with reading comprehension, mediated by word reading and nonverbal cognitive abilities. Study 2 investigated the longitudinal relationships between reading and language measures in the readers with DS over around 22 months. Time 1 listening comprehension and phonological awareness predicted Time 2 reading comprehension but there was no evidence that reading or reading comprehension predicted Time 2 language scores or phonological awareness, and no evidence that readers had acquired greater depth of vocabulary.

The role of phonological awareness and letter-sound knowledge in the reading development of children with intellectual disabilities

Our study investigated if phonological awareness and letter-sound knowledge were predictors of reading progress in children with intellectual disabilities (ID) with unspecified etiology. An academic achievement test was administered to 129 children with mild or moderate ID when they were 6-8 years old, as well as one and two school years later. Findings indicated that phonological awareness and letter-sound knowledge at 6-8 years of age predicted progress in word and non-word reading after one school year and two school years after controlling for IQ, age, expressive vocabulary, spoken language, and type of placement. Phonological awareness and letter-sound knowledge at 6-8 years of age also predicted progress in reading comprehension after one school year and two school years. These findings suggest that training phonological awareness skills combined with explicit phonics instruction is important to foster reading progress in children with mild and moderate ID with unspecified etiology.

Writing abilities in intellectual disabilities: a comparison between Down and Williams syndrome

Writing is a complex task that requires the integration of multiple cognitive, linguistic, and motor abilities. Until now, only a few studies investigated writing abilities in individuals with Intellectual Disability (ID). The aim of the present exploratory study was to provide knowledge on the organization of writing in two populations with ID, Down syndrome (DS) and Williams syndrome (WS), trying to disentangle different components of the process. A battery tapping diverse writing demands as low-level transcription skills as well as high-level writing skills was proposed to 13 individuals with WS, 12 individuals with DS and 11 mental-age-matched typically developing (TD) children. Results showed that the two groups with genetic syndromes did not differ from TD in writing a list of objects placed in bedroom, in the number of errors in the text composition, in a text copying task and in kind of errors made. However, in a word dictation task, individuals with DS made more errors than individuals with WS and TD children. In a pseudoword dictation task, both individuals with DS and WS showed more errors than TD children. Our results showed good abilities in individuals with ID in different aspects of writing, involving not only low-level transcription skills but also high-level composition skills. Contrary to the pessimistic view, considering individuals with ID vulnerable for failure, our results indicate that the presence of ID does not prevent the achievement of writing skills.

Predictors of early literacy skills in children with intellectual disabilities: a clinical perspective

The present study investigated the linguistic and cognitive predictors of early literacy in 17 children with intellectual disabilities (ID) (mean age: 7; 6 years) compared to 24 children with normal language acquisition (NLA) (mean age: 6; 0 years), who were all in the so-called partial alphabetic phase of reading (Ehri, 2005). In each group, children's performances in early literacy skills (phonological awareness, letter knowledge, and word decoding) were assessed, as well as their achievement in linguistic and cognitive measures associated to these skills. The results showed that, notwithstanding the fact that there were no differences in word decoding, children with ID lagged behind on all predictor measures relevant to early literacy skills compared to children with NLA. Moreover, whereas children with NLA showed a regular predictive pathway of early literacy skills, children with ID showed a deviant pattern, in which nonverbal intelligence and rhythmic skills proved to be of major importance. Also letter knowledge appeared to be involved in their early literacy processing. It can be tentatively concluded that in the ID group, children's level of nonverbal intellectual abilities in combination with rhythmic ability proves pivotal in the development of their early literacy skills.

Do students with Down syndrome have a specific learning profile for reading?

The present study assessed achieved reading stages of 190 school-aged children with Down syndrome (DS, age 6-20) in Bavaria, one of the most populated federal states in Germany. Teachers described the reading stages of their students in a questionnaire. The achieved stages of reading according to the developmental model of Frith are compared to a sample of 1419 students with intellectual disability (ID) regardless of etiology, but excluding DS; thereafter parallelized ID-groups were compared. Results of the questionnaire addressed to the students' teachers showed that 20.2% of the students with DS do not read at all, 7.6% read at a logographic stage, 49.4% at an alphabetic and 22.8% at an orthographic level. Alongside these findings among the whole sample, correlations are described concerning age, gender, IQ and sociocultural background. The students with DS are then compared to other students with ID with mixed etiologies. This comparison stresses the emphasis on the alphabetic level amongst students with DS. This emphasis also exists when DS and non-DS students are parallelized in groups of ID, thus showing that students with DS and severe ID are ahead in reading, but those with mild ID are behind. Knowledge about specific literacy attainment of students with DS is vital for planning instruction, for creating learning environments, and for formulating future fields of research. Especially students with DS need specific teaching which takes their impaired verbal short term memory into account, such as learning to read in syllables.

Learning to read in Williams syndrome and Down syndrome: syndrome-specific precursors and developmental trajectories

BACKGROUND

In typical development, early reading is underpinned by language skills, like vocabulary and phonological awareness (PA), as well as taught skills like letter knowledge. Less is understood about how early reading develops in children with neurodevelopmental disorders who display specific profiles of linguistic strengths and weaknesses, such as Down syndrome (DS) and Williams syndrome (WS).

METHODS

Early reading, letter knowledge, rhyme matching, phoneme matching and receptive vocabulary were assessed in 26 children with DS and 26 children with WS between 4 and 8 years, as well as in two groups of typically developing (TD) children matched on nonverbal mental age (NVMA controls) or reading (RA controls). Reading was also measured 1 year later in DS, WS and RA controls to assess reading growth and its longitudinal predictors.

RESULTS

Despite poor PA and vocabulary, children with DS displayed good reading and letter knowledge, compared with NVMA controls. Performance of children with WS was equivalent to RA controls and superior to NVMA controls on all tasks. Longitudinal delays emerged in reading in both DS and WS compared with RA controls. Vocabulary was a significant longitudinal predictor of reading growth for all children, but, for both children with DS and WS, and unlike RA controls, letter knowledge and PA were not.

CONCLUSIONS

Children with DS and WS display atypical developmental patterns in the earliest stages of reading, further underlining the importance of cross-syndrome, longitudinal research, which tracks all levels of development in neurodevelopmental disorders. Identifying early syndrome-specific profiles of strengths and weaknesses underlying literacy development is critical for planning intervention programmes.

Individuals with intellectual disability can self-teach in reading

Previous research has suggested that individuals with intellectual disability (ID) underperform in several areas of reading compared to mental age-matched peers. However, it is unclear how they compare on orthographic aspects of reading, which have to do with learning and matching the specific letter patterns in words. The leading approach to understanding orthographic learning is the self-teaching hypothesis, which suggests that orthographic learning is acquired through the experience of phonologically recoding words. The present study was a first test of the self-teaching hypothesis for individuals with ID in comparison to a group of typically developing children matched on verbal mental age. Results indicated that both groups were able to self-teach.

Strengths and weaknesses in reading skills of youth with intellectual disabilities

Reading-related skills of youth with intellectual disability (ID) were compared with those of typically developing (TD) children of similar verbal ability level. The group with ID scored lower than the TD group on word recognition and phonological decoding, but similarly on orthographic processing and rapid automatized naming (RAN). Further, phonological decoding significantly mediated the relation between group membership and word recognition, whereas neither orthographic processing nor RAN did so. The group with ID also underperformed the TD group on phonological awareness and phonological memory, both of which significantly mediated the relation between group membership and phonological decoding. These data suggest that poor word recognition in youth with ID may be due largely to poor phonological decoding, which in turn may be due largely to poor phonological awareness and poor phonological memory. More focus on phonological skills in the classroom may help students with ID to develop better word recognition skills.

Reading skills in children with Down syndrome: a meta-analytic review

The authors examine the reading profile in children with Down syndrome by comparing the nonword decoding skills in children with Down syndrome and typically developing children matched for word recognition level. Journal articles published before 04.05.2010 were identified by using the keyword Down* cross-referenced to 'reading', 'literacy', 'decoding', and 'reading comprehension' were selected. A total of eight papers met the criteria for inclusion. Each study was reviewed and coded on both inclusion criteria and coding protocol before the analysis was performed. Children with Down syndrome had equivalent nonword decoding skills to typically developing children matched for word recognition level, but showed deficits on measures of two important underlying skills, vocabulary and phonological awareness. Differences in vocabulary, but not phonological awareness, were predictive of differences in nonword decoding skills. The practical and theoretical implications of these findings are discussed.

A follow-up study on word and non-word reading skills in Down syndrome

The current study was designed to trace changes in the relationship between non-word reading and irregular word reading on the one hand, and between phonological awareness and non-word reading on the other, through a follow-up study of a group of individuals with Down syndrome. Twelve individuals with Down syndrome, whose data were originally reported in Roch and Jarrold (2008), were seen four years later, and were given the same tasks as in the previous study evaluating phonological awareness, non-word reading and irregular word reading. After four years, an improvement was observed in all the skills of interest. Furthermore, the pattern of relationships among the three skills was observed to change considerably across the four year period. At the first time point, a weak association between non-word and irregular word reading was found, but there was a strong association between these two measures at the second time point. In contrast, a strong relationship was found at Time 1 between non-word reading and phonological awareness, which became weaker at Time 2. Longitudinal associations between the three skills were also examined in order to explain this changing pattern of associations. The results indicated that the ability to decode non-words plays a marginal role on later irregular word reading. In contrast, irregular word reading is a longitudinal predictor of later non-word reading. Phonological awareness was not longitudinally related to non-word reading. The results indicate that developing word knowledge can facilitate later non-word reading in Down syndrome, perhaps by a process of reading by visual analogy to known lexical items.

LEARNING OUTCOMES

Readers will be able to (a) explain the development of word reading, non-word reading and phonological awareness in Down syndrome; (b) explain the longitudinal changes in the relationships among the three skills; (c) explain the relevance for education of the influence of word reading for the improvement in non-word reading.

IQ predicts word decoding skills in populations with intellectual disabilities

This is a study of word decoding in adolescents with Down syndrome and in adolescents with Intellectual Deficits of unknown etiology. It was designed as a replication of studies of word decoding in English speaking and in Hebrew speaking adolescents with Williams syndrome (Levy & Antebi, 2004; Levy, Smith, & Tager-Flusberg, 2003). Participants' IQ was matched to IQ in the groups with Williams syndrome and was within the range of mental retardation or borderline intelligence. Our aim was to investigate the impact of IQ on word decoding in these populations, rather than estimate their overall reading level. Similar to the results seen in people with Williams syndrome, word decoding was correlated with auditory short term memory and with phonological awareness tasks yet these correlations were mediated by IQ. It is argued that learning to decode is an explicit task that relies primarily on general cognitive resources of the kind that are most vulnerable in people with sub-normal IQ.

Memory profiles of Down, Williams, and fragile X syndromes: implications for reading development

The purpose of this review was to understand the types of memory impairments that are associated with intellectual disability (ID, formerly called mental retardation) and the implications of these impairments for reading development. Specifically, studies on working memory, delayed memory and learning, and semantic/conceptual memory in Down syndrome, Williams syndrome, and fragile X syndrome were examined. A distinct memory profile emerged for each of the 3 etiologies of ID. Memory profiles are discussed in relation to strengths and weaknesses in reading skills in these three etiologies. We suggest that reading instruction be designed to capitalize on relatively stronger memory skills while providing extra support for especially challenging aspects of reading.

Effects of targeted reading instruction on phonological awareness and phonic decoding in children with down syndrome

This research evaluated the effectiveness of reading instruction targeting oral reading and phonological awareness for children with Down syndrome (affecting chromosome 21). The participants were 7 children ranging in age from 2 years, 11 months to 10 years, 8 months. Each child acted as his/her own control, with assessments of language, cognition, phonological awareness, word and short-passage comprehension, and oral reading ability conducted on four occasions (initially, preintervention, postintervention and delayed postintervention) over approximately a 12-month period. The intervention was conducted over 10 weekly sessions and involved individual instruction. The postintervention assessment results provided evidence that phonic reading instruction was generally effective in improving reading skills and phonological awareness of children with Down syndrome.

Role of verbal memory in reading text comprehension of individuals with Down syndrome

This study analyzed the relationship between verbal memory and reading text comprehension in individuals with Down syndrome. The hypothesis that verbal memory provides unique contribution to reading text comprehension after controlling for verbal skills was tested. Twenty-three individuals with Down syndrome (ages 11 years, 2 months-18 years, 1 month) were matched on reading text comprehension, which was the primary variable of interest, with 23 typically developing children (ages 6 years, 2 months-7 years, 1 month). The two groups were compared on verbal skills and verbal memory. The results showed that working memory (concurrent storage and processing functions), but not short-term memory, predicted unique variance in reading text comprehension, after the verbal skills were controlled for. No group differences emerged in the relationship between verbal memory and reading text comprehension.

The relationship between phonological processing skills and word and nonword identification performance in children with mild intellectual disabilities

Word and nonword identification skills were examined in a sample of 80 elementary school age students with mild intellectual disabilities and mixed etiologies who were described as struggling to learn to read by their teachers. Performance on measures of receptive and expressive vocabulary, measures of phonological awareness, and measures of word and nonword identification were included for analyses. Hierarchical regression analyses indicated that, after controlling for chronological age and vocabulary knowledge, phonological processing accounted for a large and significant amount of unique variance of both word and nonword identification. In addition, the pattern of results found in this study is similar to that obtained with typically developing learners. As with typically developing children, measures of phonological awareness were significantly correlated with measures of both reading achievement and vocabulary knowledge.

Phonological awareness and writing skills in children with Down syndrome

BACKGROUND

Down syndrome, phonological awareness, writing and working memory.

AIM

to evaluate the phonological awareness of Brazilian children with Down syndrome; to analyze the relationship between the writing hypothesis and the phonological awareness scores of the participants; to compare the performance of children with Down syndrome to that of children with typical development according to the Phonological Awareness: Tool for sequential evaluation (PHONATSE), using the writing hypothesis as a matching criteria; to verify the correlation between the phonological awareness measurements and the phonological working memory.

METHOD

a group of eleven children aged between 7 and 14 years (average: 9 y 10 m) was selected for the study. Phonological awareness was evaluated using the PHONATSE. The phonological working memory was evaluated through an instrument developed by the researcher.

RESULTS

all subjects presented measurable levels of phonological awareness through the PHONATSE. The phonological awareness scores and the writing hypothesis presented a significant positive association. The performance of children with Down syndrome was significantly lower than children with typical development who presented the same writing hypothesis. Measurements of phonological awareness and phonological working memory presented significant positive correlations.

CONCLUSION

the phonological awareness of Brazilian children with Down syndrome can be evaluated through the PHONATSE. Syllable awareness improves with literacy, whereas phonemic awareness seems to result from written language learning. The phonological working memory influences the performance of children with Down syndrome in phonological awareness tasks.

Eye-movement patterns of readers with down syndrome during sentence-processing: an exploratory study

Eye movements were examined to determine how readers with Down syndrome process sentences online. Participants were 9 individuals with Down syndrome ranging in reading level from Grades 1 to 3 and a reading-level-matched control group. For syntactically simple sentences, the pattern of reading times was similar for the two groups, with longer reading times found at sentence end. This "wrap-up" effect was also found in the first reading of more complex sentences for the control group, whereas it only emerged later for the readers with Down syndrome. Our results provide evidence that eye movements can be used to investigate reading in individuals with Down syndrome and underline the need for future studies.

Aneuploidy: from a physiological mechanism of variance to Down syndrome

Quantitative differences in gene expression emerge as a significant source of variation in natural populations, representing an important substrate for evolution and accounting for a considerable fraction of phenotypic diversity. However, perturbation of gene expression is also the main factor in determining the molecular pathogenesis of numerous aneuploid disorders. In this review, we focus on Down syndrome (DS) as the prototype of "genomic disorder" induced by copy number change. The understanding of the pathogenicity of the extra genomic material in trisomy 21 has accelerated in the last years due to the recent advances in genome sequencing, comparative genome analysis, functional genome exploration, and the use of model organisms. We present recent data on the role of genome-altering processes in the generation of diversity in DS neural phenotypes focusing on the impact of trisomy on brain structure and mental retardation and on biological pathways and cell types in target brain regions (including prefrontal cortex, hippocampus, cerebellum, and basal ganglia). We also review the potential that genetically engineered mouse models of DS bring into the understanding of the molecular biology of human learning disorders.

Language Characteristics of Individuals with Down Syndrome

On average, language and communication characteristics of individuals with Down syndrome (the most common genetic cause of intellectual disability) follow a consistent profile. Despite considerable individual variability, receptive language is typically stronger than expressive language, with particular challenges in phonology and syntax. We review the literature on language and literacy skills of individuals with Down syndrome, with emphasis on the areas of phonology, vocabulary, syntax, and pragmatics. We begin by describing the hearing, oral-motor, cognitive, social, and prelinguistic and early nonverbal communication characteristics of individuals with Down syndrome. We conclude with a discussion of clinical implications and research directions.

A comparison between word and nonword reading in Down syndrome: the role of phonological awareness

In order to examine whether any observed relationship between phonological awareness and reading ability in Down syndrome reflects the typical use of a phonologically based approach to reading, 12 children and young adults with Down syndrome were assessed for reading and phonological awareness skills. They were compared to a control group of 14 typically developing 6- and 7-year-olds of comparable word reading abilities. Results showed that, although individuals with Down syndrome had impaired nonword reading and phonological awareness skills, the same relationship held between these two abilities as was observed in the group of typically developing children. Moreover, individuals with Down syndrome read at least as well as the typically developing children when the task required a visual reading strategy (reading irregular words).

LEARNING OUTCOMES

(a) understanding of the main issues related to the development of reading skills in Down syndrome; (b) understanding of the role played by phonological awareness in learning to read; (c) understanding of the importance for education of the strong relationship between phonological awareness and reading skills in Down syndrome.

Language development in Down syndrome: from the prelinguistic period to the acquisition of literacy

Down syndrome (DS) is associated with abnormalities in multiple organ systems and a characteristic phenotype that includes numerous behavioral features. Language, however, is among the most impaired domains of functioning in DS and, perhaps, also the greatest barrier to independent meaningful inclusion in the community. In this article, we review what is known about the extent, nature, and correlates of the language and related problems of individuals with Down syndrome. In doing so, we focus largely on the syndrome-specific features of the language phenotype, although we also consider within-syndrome variation. The review focuses on the prelinguistic foundations of language and the major components of language (i.e., vocabulary, syntax, and pragmatics). We also consider two topics in the treatment and education of individuals with DS: prelinguistic communication intervention and the acquisition of literacy skills.

Language and communication development in down syndrome

Although there is considerable variability, most individuals with Down syndrome have mental retardation and speech and language deficits, particularly in language production and syntax and poor speech intelligibility. This article describes research findings in the language and communication development of individuals with Down syndrome, first briefly describing the physical and cognitive phenotype of Down syndrome, and two communication related domains-hearing and oral motor skills. Next, we describe language development in Down syndrome, focusing on communication behaviors in the prelinguistic period, then the development of language in children and adolescents, and finally language development in adults and the aging period. We describe language development in individuals with Down syndrome across four domains: phonology, semantics, syntax, and pragmatics. Wethen suggest strategies for intervention and directions for research relating to individuals with Down syndrome.