Nouns and predicates comprehension and production in children with Down syndrome

The role of imageability in noun and verb acquisition in children with Down syndrome and their peers with typical development

Our main objective was to analyze the role of imageability in relation to the age of acquisition (AoA) of nouns and verbs in Spanish-speaking children with Down syndrome (DS) and their peers with typical development (TD). The AoA of nouns and verbs was determined using the MacArthur-Bates CDIs adapted to the profile of children with DS. The AoA was analyzed using a linear mixed-effect model, including factors of imageability, group, and word class, and controlling for word frequency and word length. This analysis showed that high imaginable and short words were acquired early. Children with DS acquired the words later than TD peers. An interaction between imageability and group indicated that the effect of imageability was greater in the DS group. We discuss this effect considering DS children's phonological memory difficulties. The overall results confirm the role that imageability and word length play in lexical acquisition, an effect that goes beyond word class.

Word type and modality in the emerging expressive vocabularies of preschool children with Down syndrome

BACKGROUND

Previous studies have explored the size and word type composition (nouns, predicates, etc.) of expressive vocabularies of preschool children with Down syndrome, both spoken and signed. Separately, overall preferences for modality of expression have also been explored.

AIMS

To extend previous findings by describing the relationships between expressive vocabulary size and both word type and modality of expression in the preschool period including changes to modality preference over time.

METHODS & PROCEDURES

Mothers of 35 children with Down syndrome, aged 36-66 months and attending the same early intervention programme, completed a version - with both spoken word and sign options - of the New Zealand MacArthur-Bates Communicative Development Inventory (CDI): Words and Sentences. Most mothers completed the CDI on multiple occasions across the duration of the study. Completions (n = 114) were analysed cross-sectionally and longitudinally in terms of (1) word type relative to vocabulary size, (2) modality of expression relative to word type and vocabulary size, and (3) individual trajectories in vocabulary size and modality of expression.

OUTCOMES & RESULTS

(1) Word type relative to vocabulary size was similar to previous studies with a greater proportion of the SOCIAL words being present in the children's vocabularies throughout, followed by NOUNS, PREDICATES and CLOSED class words, with proportions converging as vocabulary sizes increase. (2) An initial spoken word preference for SOCIAL and CLOSED class words and sign preference for NOUNS and PREDICATES was found, with more spoken words in larger vocabularies overall. (3) Individual trajectories were highly variable and also revealed temporary points of regression in overall expressive vocabulary size in some children. Children who shifted from reliance on sign to predominantly spoken word expression did so at different ages and at different vocabulary sizes. At school entry, while most of the children used both modalities, some children continued to rely on sign for most vocabulary items whereas others used only spoken words.

CONCLUSIONS & IMPLICATIONS

An appreciation of both the general trends and potential for individual variation in vocabulary structure, modality of expression and change over time will better position clinicians and education specialists to provide individually tailored support to both preschool and school-aged children with Down syndrome.

WHAT THIS STUDY ADDS

What is already known on this subject Preschool children with Down syndrome have been shown to demonstrate developmental patterns in overall conceptual vocabulary size and word type development broadly similar to typical development. The use of signed vocabulary has also been explored, but independently from word type development and with less attention to individual trajectories in either vocabulary size development or modality preferences throughout the preschool period than is necessary for clinical use. What this paper adds to existing knowledge This study found interactions between word type and modality of expression in relation to vocabulary size as well as a few temporary vocabulary size regressions similar to those found in much younger typically developing children. An initial spoken word preference for social and closed class words, and sign preference for nouns and predicates, was followed by a general trend towards spoken words for all word types as vocabulary (with some fluctuations) increased over time. Children demonstrated considerable individual variation in size of vocabulary and age at which they pivoted from a signed to a spoken word preference. Moreover, while most children used both modalities at school entry, a few retained a sign-only vocabulary and others had moved fully onto spoken word-only expression. What are the potential or actual clinical implications of this work? An understanding of both the general trends and individual variation in vocabulary structure and modality of expression development will better position clinicians and educational specialists to provide individually tailored support to children with Down syndrome.

Do Spoken Vocabulary and Gestural Production Distinguish Children with Transient Language Delay from Children Who Will Show Developmental Language Disorder? A Pilot Study

The literature on the role of gestures in children with language delay (LD) is partial and controversial. The present study explores gestural production and modality of expression in children with LD and semantic and temporal relationships between gestures and words in gesture + word combinations. Thirty-three children participated (mean age, 26 months), who were recruited through a screening programme for LD. Cognitive skills, lexical abilities, and the use of spontaneous gestures in a naming task were evaluated when the children were 32 months old. When the children were 78 months old, their parents were interviewed to collect information about an eventual diagnosis of developmental language disorder (DLD). According to these data, the children fell into three groups: children with typical development (n = 13), children with LD who did not show DLD (transient LD; n = 9), and children with LD who showed DLD (n = 11). No significant differences emerged between the three groups for cognitive and lexical skills (comprehension and production), for number of gestures spontaneously produced, and for the sematic relationships between gestures and words. Differences emerged in the modality of expression, where children with transient LD produced more unimodal gestural utterances than typical-development children, and in the temporal relationships between gestures and words, where the children who would show DLD provided more frequent representational gestures before the spoken answer than typical-development children. We suggest a different function for gestures in children with T-LD, who used representational gestures to replace the spoken word they were not yet able to produce, and in children with LD-DLD, who used representational gestures to access spoken words.

Social abilities in young Mexicans with Down syndrome during the COVID-19 pandemic

Background: Social abilities include interpersonal skills, interaction, and social responsibility. The nature of these abilities has not been explored in young people with Down syndrome (DS) during the social isolation of the COVID-19 pandemic. Method: The aim of this online study was to describe the social profile of a group of 30 Mexican people with DS, with a chronological age of 15-29 years, and explore the variables related to their psychosocial profiles. A sociodemographic questionnaire, mental age examination, and socialization battery were applied. Social behavior was analyzed in domains that facilitate socialization (leadership, joviality, social sensitivity, respect/self-control), in domains that disrupt socialization (aggressiveness/stubbornness, apathy/withdrawal, anxiety/shyness), and on a global scale. Results: Participants' scores in the facilitative domains were above average, and their scores in the disruptive domains were below average, as expected. Scores on the respect/self-control scale were associated with chronological age (CA), and those on the global scale with mental age (MA). Discussion: No impairments were found in the social skills of young people with DS according to the parameters of the scale. The development of the social profile with CA and MA stimulates cognition and promotes independence, autonomy, and proactivity. Parents' role in regulating children's behavior was an important factor in managing their social isolation during the COVID-19 pandemic.

Opportunities, barriers, and recommendations in down syndrome research

BACKGROUND

Recent advances in medical care have increased life expectancy and improved the quality of life for people with Down syndrome (DS). These advances are the result of both pre-clinical and clinical research but much about DS is still poorly understood. In 2020, the NIH announced their plan to update their DS research plan and requested input from the scientific and advocacy community.

OBJECTIVE

The National Down Syndrome Society (NDSS) and the LuMind IDSC Foundation worked together with scientific and medical experts to develop recommendations for the NIH research plan.

METHODS

NDSS and LuMind IDSC assembled over 50 experts across multiple disciplines and organized them in eleven working groups focused on specific issues for people with DS.

RESULTS

This review article summarizes the research gaps and recommendations that have the potential to improve the health and quality of life for people with DS within the next decade.

CONCLUSIONS

This review highlights many of the scientific gaps that exist in DS research. Based on these gaps, a multidisciplinary group of DS experts has made recommendations to advance DS research. This paper may also aid policymakers and the DS community to build a comprehensive national DS research strategy.

Intervención temprana en Síndrome de Down: Una revisión sistemática

Introducción: El síndrome de Down presenta importantes diferencias en tasas de incidencia según territorios y países, siendo además una de los trastornos genéticos más complejos, aunque su detección sea la más precoz de los trastornos genéticos. En España se ha producido una drástica reducción de nacimientos, existiendo un aumento en otras zonas del mundo como Latinoamérica. Objetivo y método: Se pretende realizar una revisión sistemática sobre el conocimiento científico actual relacionado con intervenciones tempranas en SD desde los años 2000 al 2017, utilizando la metodología PRISMA. Resultados: Se observa intensas lagunas metodológicas, enfatizándose las investigaciones transversales por encima de los longitudinales y sobre todo en zonas concretas del mundo. De este síndrome siguen interesando los factores cognitivos en detrimento de variables familiares y otros aspectos claves para un desarrollo psicoevolutivo adecuado. No se observan trabajos de intervención temprana ni de evaluación de programas en países hispanohablantes, y la mayoría de publicaciones científicas mezclan edades y sexos en sus muestras. Discusión: Se discuten los resultados obtenidos de la revisión realizada. Conclusiones: A lo largo del tiempo se observa una importante reducción del interés científico por este síndrome. Se siguen realizando trabajos de manera redundante sobre los mismos aspectos, sin valorar subdimensiones imprescindibles para el desarrollo biopsicosocial de este colectivo.

The Italian Words and Sentences MB-CDI: normative data and concordance between complete and short forms

One of the most popular and widely used parent report instruments for assessing early language acquisition is the MacArthur-Bates Communicative Development Inventories (MB-CDI). This study compares normative data of the Italian Words and Sentences complete form (WS-CF) and short form (WS-SF). The samples included 752 children for the WS-CF and 816 children for the WS-SF designed for children aged 18-36 months. The concordance between WS-SF and WS-CF is analyzed in a subgroup of 65 children. The results revealed strong correlations between WS-CF and WS-SF in both lexical and grammar skills as well as strong relationship between lexical and grammar skills. There was a high percentage agreement (97%) between the two forms for scores below the 10th percentile, suggesting that the two forms may be used interchangeably in order to describe vocabulary and grammatical development.

Predictors of receptive and expressive vocabulary development in children with Down syndrome

PURPOSE

There is a lack of longitudinal data on predictors of vocabulary development in children with Down syndrome (DS). In typically developing children, many internal and external predictors of vocabulary development have been determined before. The purpose of the present study was to investigate the role of these variables in the receptive and expressive vocabulary development of children with DS.

METHOD

The present study used a longitudinal design in young children with DS to study the vocabulary development over a period of 1.6 years and investigated the possible predictive role of child-related and environmental variables.

RESULT

Receptive vocabulary development was best predicted by the adaptive level of functioning and early receptive vocabulary skills. Expressive vocabulary development was best predicted by the adaptive level of functioning, receptive vocabulary, maternal educational level, level of communicative intent of the child, attention skills and phonological/phonemic awareness.

CONCLUSION

A wide range of internal and external predictors for vocabulary development of children with DS was found. Predictors resemble those predicting vocabulary development in peers with typical development between 1 and 6 years of age, as identified in other studies.

The acquisition of different classes of words in Spanish children with Down syndrome

PURPOSE

The primary aim of this study was to analyze the acquisition of different classes of words in Spanish-speaking children with Down syndrome (DS), with special emphasis on nouns and verbs. A second objective was to compare the results obtained with those reported by Checa et al. (2016), who used a different measure to study vocabulary composition.

METHOD

We studied 108 children with DS and 108 children with typical development (TD), with mental ages between 9 and 29 months (DS M = 21;26 months;days, TD M = 20;23) and chronological ages between 8;24 and 68;19 months;days (mean = 41;11 and 20;19 for DS and TD, respectively). Children were matched individually for size of productive vocabulary and gender. Data were gathered using the MacArthur-Bates CDIs, adapted to the profile of children with DS (the CDI-Down). Relative proportions were used as the measure of vocabulary.

RESULTS

The results differed from those obtained by Checa et al. (2016) when using absolute proportions to examine vocabulary composition. The most significant difference was the trend among children with DS to produce fewer verbs and closed-class words (articles, prepositions, pronouns, conjunctions, and auxiliaries). There were no differences in the production of nouns and social words.

CONCLUSIONS

The tendency of children with DS to produce fewer verbs and closed-class words could be due to difficulties with morphology and syntax. This underlines the importance of morphosyntactic skills for learning these classes of words. The methodological and clinical implications of the results are discussed.

Speech-language therapy stimulation in children with Down’s syndrome

ABSTRACT Objective: to analyze the contributions of speech-language therapy to the language development of children with Down syndrome (DS). Methods: eleven children with DS participated in the research. The children were between zero and five years of age, of both genders and attending a university extension project involving eight therapy sessions following stimulation guidelines. Children were evaluated before and after speech-language stimulation. The stimulation guidelines were based on the following aspects of language development: coordination of sensorimotor schema, constitution of object permanence, gestural/body imitation, imitation of utterances, deferred imitation and use of symbolic schema, communicative intent, receptive vocabulary and expressive vocabulary: words and phrases. The study was approved by the Research Ethics Committee of the institution. Data were analyzed quantitatively. Results: there were significant differences in the pre- and post-speech-language intervention in the following skills parameters: gestural/body imitation, imitation of utterances, deferred imitation and use of symbolic schema, communicative intent and receptive vocabulary. Conclusion: early stimulation of linguistic and cognitive aspects is important in the development of children with DS, as evidenced by the immediate development of speech-language skills in children after the intervention.

Contextual effects on semantic grouping in individuals with Down syndrome

OBJECTIVE

Individuals with Down syndrome have impaired linguistic ability but relatively good visuospatial cognition. A verbal-with-visual presentation enhanced the semantic grouping in individuals with Down syndrome, whereas a verbal presentation did not have this effect. This study aims to examine the influence of visual presentation on semantic grouping in individuals with Down syndrome.

METHOD

Pictures that depict backgrounds and targets as pairs were shown to participants who were asked to make judgments according to semantic appropriateness. Targets in the same category were matched to the background in congruent and incongruent conditions.

RESULTS

Unlike two groups of typical developers, the studied group failed to display the congruency effect. They responded slowest to congruent conditions and had the lowest accuracy rates. Error patterns revealed that they exhibited coarse semantic classification.

CONCLUSIONS

Through a visual presentation that provided contexts, an atypical contextual effect on semantic grouping was revealed in individuals with Down syndrome.

Core vocabulary of young children with Down syndrome

The aim of this study was to develop a core vocabulary list for young children with intellectual disabilities between 2 and 7 years of age because data from this population are lacking in core vocabulary literature. Children with Down syndrome are considered one of the most valid reference groups for researching developmental patterns in children with intellectual disabilities; therefore, spontaneous language samples of 30 Dutch children with Down syndrome were collected during three different activities with multiple communication partners (free play with parents, lunch- or snack-time at home or at school, and speech therapy sessions). Of these children, 19 used multimodal communication, primarily manual signs and speech. Functional word use in both modalities was transcribed. The 50 most frequently used core words accounted for 67.2% of total word use; 16 words comprised core vocabulary, based on commonality. These data are consistent with similar studies related to the core vocabularies of preschoolers and toddlers with typical development, although the number of nouns present on the core vocabulary list was higher for the children in the present study. This finding can be explained by manual sign use of the children with Down syndrome and is reflective of their expressive vocabulary ages.

Consideração da idade mental na avaliação do vocabulário expressivo de crianças com Síndrome de Down

RESUMO Objetivo: verificar vocabulário expressivo de crianças com Síndrome de Down, comparar ao desempenho de crianças com desenvolvimento típico de mesmo gênero em dois pareamentos distintos: considerando idade cronológica e mental, separadamente, e determinar a influência da idade considerada na avaliação desta população. Métodos: cumpriram-se aspectos éticos. Participaram 14 com Síndrome de Down, idade cronológica entre 38 a 63 meses, 14 com desenvolvimento típico pareado por gênero e idade mental e 14 com desenvolvimento típico pareado por gênero e idade cronológica. Após entrevista, aplicou-se Teste de Linguagem Infantil ABFW-Vocabulário Parte B. Para pareamento da idade mental utilizou-se o teste Stanford Binet. Aplicação do teste paramétrico ANOVA, teste Kruskal-Walis e Teste Tukey, quando necessário. Resultados: verificou-se desempenho inferior das crianças com Síndrome de Down comparadas ao grupo pareado por idade cronológica para nomeação correta e não nomeação das figuras. Não houve diferença significante entre o grupo com Síndrome de Down e com desenvolvimento típico pareado por idade mental. Conclusão: as crianças com Síndrome de Down apresentaram vocabulário expressivo aquém do esperado para a idade cronológica, porém próximo ao esperado para a idade mental, permitindo inferir que a idade considerada na avaliação da linguagem desta população interfere na análise dos resultados encontrados.

The concurrent and predictive validity of the Dutch version of the Communicative Development Inventory in children with Down Syndrome for the assessment of expressive vocabulary in verbal and signed modalities

The expressive vocabulary of children with Down Syndrome (DS) is generally measured with parental reports, such as the Communicative Development Inventory (CDI), given that standardized tests for assessing vocabulary levels may be too difficult for most young children with DS. The CDI provides important insight into the parents' perception of their child's vocabulary development. The CDI has proven to be a valid measurement of expressive vocabulary, spoken and gestural, in typical and atypical populations. The validity in children with DS is not well established and signed vocabulary is often not included. This longitudinal study examined the concurrent and predictive validity of the Dutch version of the CDI (N-CDI) in children with DS between 2;0 and 7;6 years old to assess spoken and signed vocabulary. N-CDI scores were assessed on strength of association with mental age, an expressive vocabulary test and spontaneous language analyses in a play setting with parents at T1 and T2 (1.5 years later), and a therapy setting with speech language pathologists at T1. The results of the present study show that the N-CDI is a valuable and valid measurement of expressive vocabulary in children with DS. Strengths and weaknesses of several assessment methods for expressive vocabulary are discussed.

Spontaneous Gesture Production and Lexical Abilities in Children With Specific Language Impairment in a Naming Task

PURPOSE

The purpose of the study was to investigate the role that cospeech gestures play in lexical production in preschool-age children with expressive specific language impairment (E-SLI).

METHOD

Fifteen preschoolers with E-SLI and 2 groups of typically developing (TD) children matched for chronological age (n = 15, CATD group) and for language abilities (n = 15, LATD group) completed a picture-naming task. The accuracy of the spoken answers (coded for types of correct and incorrect answers), the modality of expression (spoken and/or gestural), types of gestures, and semantic relationship between gestures and speech produced by children in the different groups were compared.

RESULTS

Children with SLI produced higher rates of phonological simplifications and unintelligible answers than CATD children, but lower rates of semantic errors than LATD children. They did not show a significant preference for spoken answers, as TD children did. Similarly to LATD children, they used gestures at higher rates than CATD, both deictic and representational, and both reinforcing the information conveyed in speech and adding correct information to co-occurring speech.

CONCLUSIONS

These findings support the hypotheses that children with SLI rely on gestures for scaffolding their speech and do not have a clear preference for the spoken modality, as TD children do, and have implications for educational and clinical practice.

Noun and predicate comprehension/production and gestures in extremely preterm children at two years of age: Are they delayed?

Extremely low gestational age (ELGA, GA<28 weeks) preterm children are at high risk for linguistic impairments; however, their lexical comprehension and production as well as lexical categories in their early language acquisition have not been specifically examined via direct tools. Our study examines lexical comprehension and production as well as gestural production in ELGA children by focusing on noun and predicate acquisition. Forty monolingual ELGA children (mean GA of 26.7 weeks) and 40 full-term (FT) children were assessed at two years of corrected chronological age (CCA) using a test of noun and predicate comprehension and production (PiNG) and the Italian MB-CDI. Noun comprehension and production were delayed in ELGA compared with FT children, as documented by the low number of correct responses and the large number of errors, i.e., incorrect responses and no-response items, and by the types of incorrect responses, i.e., fewer semantically related responses, in noun production. Regarding predicate comprehension and production, a higher frequency of no responses was reported by ELGA children and these children also presented a lower frequency of bimodal spoken-gestural responses in predicate production than FT children. A delayed vocabulary size as demonstrated by the MB-CDI, was exhibited by one-fourth of the ELGA children, who were also unable to complete the predicate subtest. These findings highlight that noun comprehension and production are delayed in ELGA children at two years of CCA and are the most important indexes for the direct evaluation of their lexical abilities and delay. The types of incorrect responses and bimodal spoken-gestural responses were proven to be useful indexes for evaluating the noun and predicate level of acquisition and to plan early focused interventions.

LEARNING OUTCOMES

After reading this manuscript, the reader will understand (a) the differences in noun and predicate comprehension and production between ELGA and FT children and the indexes of lexical delays exhibited by ELGA children at 2;0 (CCA); (b) the relevance of evaluating errors (incorrect response and no response), the types of incorrect responses (semantically related and unrelated) and the modality of the responses (unimodal spoken and bimodal spoken-gestural) in noun and predicate production to understand the difficulties experienced by ELGA children in representing and expressing meanings; and (c) the need to plan specific interventions to support spoken and gestural modalities in lexical comprehension and production in ELGA children by focusing on noun and predicate acquisition.