Effect of memory support and elicited production on fast mapping of new words by adolescents with Down syndrome

Strategies for Teaching Verbs to Children with and without Language Impairment

The aim of this feasibility study was to extend the current evidence base on intransitive verb learning by evaluating and comparing three strategies (syntactic cues, semantic cues, combined cues) for teaching novel verbs to expand the vocabularies of children with and without language impairment. Twenty-three children with typical development, seven children with developmental language disorder, and eight children with Down syndrome participated in Studies 1, 2, and 3, respectively. They were taught novel, intransitive verbs using syntactic, semantic, and combined cues and then asked to receptively identify and expressively label the novel verbs. Across all conditions, participants learned novel verbs receptively with large effect sizes and participants with typical development and Down syndrome also learned the verbs expressively with large effect sizes. There were no significant differences between conditions. This study extends word-learning research by evaluating not only receptive but also expressive intransitive verb learning to expand one's vocabulary. The results provide positive evidence for three effective strategies for teaching intransitive verbs to children with and without language impairment.

Modeling the Relations Among Sustained Attention, Short-Term Memory, and Language in Down Syndrome

Sustained attention (SA) and short-term memory (STM) contribute to language function in Down syndrome (DS). We proposed models in which relations of SA to language in DS are mediated by STM. Thirty-seven youth with DS aged 10-22 years (M = 15.59) completed SA, STM, and language tasks. Cross-sectional mediation analyses were run with the bootstrapping method. We found significant indirect effects of SA separately on vocabulary and syntax through auditory STM with point estimates of -.30 and -.31, respectively. Results suggest lapses in SA compromise auditory STM, which in turn impacts vocabulary and syntax in youth with DS; however, further research is needed to confirm causality. Addressing SA and STM in language therapy with youth with DS could lead to improved outcomes.

Verbal short-term memory shows a specific association with receptive but not productive vocabulary measures in Down syndrome

BACKGROUND

Verbal short-term memory (STM) capacity has been considered to support vocabulary learning in typical children and adults, but evidence for this link is inconsistent for studies in individuals with Down syndrome (DS). The aim of this study was explore the role of processing demands on the association between verbal STM and vocabulary measures in DS, by comparing receptive vocabulary measures with high STM processing demands to productive vocabulary measures with low STM processing demands.

METHOD

Forty-seven adults with Down syndrome were administered receptive vocabulary and productive vocabulary tasks, as well as measures of verbal STM abilities and intellectual efficiency.

RESULTS

Bayesian regression analyses showed that verbal STM abilities were strongly and specifically associated with receptive vocabulary measures but not productive lexical abilities after controlling for intellectual efficiency, and this is despite the fact that vocabulary abilities as measured by receptive and productive vocabulary tasks were closely associated.

CONCLUSIONS

In Down syndrome, verbal STM abilities may be predictive of specific task demands associated with receptive vocabulary tasks rather than of vocabulary development per se.

The Composition of Early Vocabulary in Spanish Children With Down Syndrome and Their Peers With Typical Development

PURPOSE

There are very few studies, and at present none in Spanish, on vocabulary composition in children with Down syndrome (DS). Nor has the topic been widely assessed in Spanish-speaking children with typical development (TD). This study analyzed the composition of early vocabularies in a large sample of Spanish-speaking children with DS and compared it with that of children with TD.

METHOD

We studied 108 children with DS and 108 children with TD with mental ages between 8 and 29 months, matched for size of productive vocabulary and gender. The MacArthur-Bates Communicative Development Inventories (Fenson et al., 1993, 2007), adapted to the language development profile of children with DS, were used. The categories examined were nouns, predicates, closed-class words, and social words.

RESULTS

The performance of children with DS was similar to that of children with TD with the same vocabulary size. The only significant difference was the larger production of nouns by children with DS. The trends of development in the different classes of words were also similar.

CONCLUSIONS

The strategies used by children with DS to learn vocabulary may be similar to those used by children with TD in the first stages of language learning.

Addressing phonological memory in language therapy with clients who have Down syndrome: Perspectives of speech-language pathologists

BACKGROUND

Phonological memory (PM) plays a significant role in language development but is impaired in individuals with Down syndrome (DS). Without formal recommendations on how to address PM limitations in clients with DS, it is possible speech-language pathologists (SLPs) find ways to do so in their practices.

AIMS

This study asked if and how SLPs address PM in language therapy with clients who have DS. It also asked about SLPs' opinions of the importance, practicality and difficulty of addressing PM in clients with DS.

METHODS & PROCEDURES

SLPs participated in an online survey that asked if they address PM in clients with DS and, if so, how often and with which techniques. The survey also asked SLPs to rate their opinions of addressing PM in clients with DS with Likert scales. To contrast clients with DS, SLPs were asked about their practices and opinions with clients who have specific language impairment (SLI) and autism spectrum disorders (ASD). SLPs were recruited through e-mails sent from state organizations and researchers. To compare SLPs' practices and opinions across client types, frequency analyses and analyses of variance (ANOVAs) were run.

OUTCOMES & RESULTS

In all, 290 SLPs from 28 states completed the survey. Nearly all SLPs were currently practising at the time data were collected, and all worked with at least one of the three client types. Findings indicated SLPs less often addressed PM and used less variety when addressing PM with clients who have DS compared with clients who have SLI or ASD. Further, SLPs considered it less important, less practical and more difficult to address PM in clients who have DS when compared with clients who have SLI, whereas a similar pattern was found with clients who have ASD.

CONCLUSIONS & IMPLICATIONS

SLPs' opinions could be one reason they under-address PM with clients who have DS. Other reasons include there are no evidence-based practice (EBP) guidelines on this topic, and there is not enough familiarity with the DS phenotype among SLPs. Future research on ways to address PM in clients with DS successfully are essential so that EBP guidelines can be established and language therapy can be made more effective.

Syntactic bootstrapping in children with Down syndrome: the impact of bilingualism

PURPOSE

The purpose of the study was to add to our knowledge of bilingual learning in children with Down syndrome (DS) using a syntactic bootstrapping task.

METHOD

Four groups of children and youth matched on non-verbal mental age participated. There were 14 bilingual participants with DS (DS-B, mean age 12;5), 12 monolingual participants with DS (DS-M, mean age 10;10), 9 bilingual typically developing children (TD-B; mean age 4;1) and 11 monolingual typically developing children (TD-M; mean age 4;1). The participants completed a computerized syntactic bootstrapping task involving unfamiliar nouns and verbs. The syntactic cues employed were a for the nouns and ing for the verbs.

RESULTS

Performance was better on nouns than verbs. There was also a main effect for group. Follow-up t-tests revealed that there were no significant differences between the TD-M and TD-B or between the DS-M and DS-B groups. However, the DS-M group performed more poorly than the TD-M group with a large effect size. Analyses at the individual level revealed a similar pattern of results.

CONCLUSION

There was evidence that Down syndrome impacted performance; there was no evidence that bilingualism negatively affected the syntactic bootstrapping skills of individuals with DS. These results from a dynamic language task are consistent with those of previous studies that used static or product measures. Thus, the results are consistent with the position that parents should be supported in their decision to provide bilingual input to their children with DS.

LEARNING OUTCOMES

Readers of this article will identify (1) research evidence regarding bilingual development in children with Down syndrome and (2) syntactic bootstrapping skills in monolingual and bilingual children who are typically developing or who have Down syndrome.

The role of linguistic context in deriving word meanings in individuals with Down Syndrome

Deriving the meaning of unknown words from context and its relationship to text comprehension was investigated in 24 individuals with Down syndrome and in 24 typically developing children matched for the Peabody Picture Vocabulary Test (PPVT) score. The study consisted of three phases. Unknown words were identified during the first phase (PPVT). Those words were presented embedded in brief linguistic contexts during the second phase. Recognition (maintenance) of word meanings was verified in the third and final phase. Both groups of participants recognized the meanings of a noteworthy number of words in contexts and a high percentage of these was maintained when they were presented at a later date without the support of context. Over and above group differences and basic linguistic skills, text comprehension seems to predict the ability to use context. Context provides the semantic information necessary to extract word meaning by activating relevant world knowledge.

Evidence for preserved novel word learning in Down syndrome suggests multiple routes to vocabulary acquisition

PURPOSE

Three studies investigated novel word learning, some requiring phonological production, each involving between 11 and 17 individuals with Down syndrome, and between 15 and 24 typically developing individuals matched for receptive vocabulary. The effect of stimuli wordlikeness and incidental procedure-based memory demands were examined to see whether these may account for an apparent impairment in word learning in Down syndrome demonstrated in earlier research.

METHOD

Paired associate word and nonword learning tasks were presented, requiring participants to learn the names of novel characters. The nonword stimuli varied in the degree of wordlikeness in 2 studies. A third study investigated extraneous task demand.

RESULTS

Across 3 studies, there was no suggestion of a word learning deficit associated with Down syndrome (η(2)(p) for the main effect of group of .03, .11, and .03, respectively), despite the level of phonological representation required. There was evidence that novel word learning by participants with Down syndrome exceeded that which their verbal short-term memory capacity would predict.

CONCLUSIONS

Vocabulary acquisition in Down syndrome may not rely on verbal short-term memory to the same extent as in typically developing children, lending support to the suggestion that new word learning may be underpinned by an additional memory process.

Habilidade pragmática e Síndrome de Down

OBJETIVO: investigar as habilidades pragmáticas em sujeitos com Síndrome de Down e sua influência no uso comunicativo. MÉTODOS: avaliação da pragmática (ABFW). Participaram desta pesquisa 10 crianças e adolescentes, de ambos os sexos, com idades entre sete e treze anos. A coleta de dados foi realizada a partir de uma situação de brincadeira livre com um familiar. Os padrões de comportamento foram analisados por meio das funções comunicativas, dos meios de comunicação (vocal, gestual ou verbal) e dos atos comunicativos. Os resultados foram tratados estatisticamente (p < 0.05 Kruskal-Wallis; Q1 = n/4 Q2 = n/2 Q3 =3n/4 (n = 10) Primeiro Quartil, Mediana, Terceiro Quartil. RESULTADOS: foram realizados em média 2.88 atos comunicativos por minuto. Entre as funções comunicativas as de maior frequência foram a comentário e a narrativa. O meio comunicativo de maior frequência foi o verbal. Todos os participantes utilizaram as funções comunicativas: comentário, reconhecimento do outro e jogo compartilhado e 90% do direcionamento da comunicação foi realizado pelas crianças e adolescentes. CONCLUSÃO: os meios comunicativos verbal e gestual foram os mais utilizados pelos participantes do estudo. Em relação às funções comunicativas observou-se a predominância da função comentário e narrativa. O direcionamento da comunicação foi realizado predominantemente pelas crianças e adolescentes participantes do estudo.

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.

Use of speaker intent and grammatical cues in fast-mapping by adolescents with Down syndrome

PURPOSE

The authors asked whether adolescents with Down syndrome (DS) could fast-map novel nouns and verbs when word learning depended on using the speaker's pragmatic or syntactic cues. Compared with typically developing (TD) comparison children, the authors predicted that syntactic cues would prove harder for the group with DS to use and that action verbs would be harder to fast-map than nouns.

METHOD

Twenty participants with DS, aged 12-18 years, and 19 TD participants, aged 3-6 years, were matched on syntax comprehension and engaged in 4 fast-mapping tasks. Both comprehension and production of novel words were assessed for each task. Through use of hierarchical regression models, hearing, cognition, and working memory were considered as predictors of total comprehension and production performance for each group.

RESULTS

Both groups used speaker intent in fast-mapping labels to object referents but performed more poorly on fast-mapping verbs. Neither group appeared to use grammatical cues to disambiguate the intended referent. Syntax comprehension was replicated as a predictor of fast-mapping comprehension for the DS group. Syntax comprehension and chronological age were replicated as predictors of TD fast-mapping.

CONCLUSION

Participants with DS had better recall for the object or action seen most recently during speaker intent tasks. They had better recall for the object presented first and the action presented last during grammatical cue tasks. Response patterns may have depended on the structure of specific task paradigms. Verb acquisition may be facilitated when either the action or label is familiar.

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.