Early predictors of communication development in young children with autism spectrum disorder: joint attention, imitation, and toy play.
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This study investigated the unique contributions of joint attention, imitation, and toy play to language ability and rate of development of communication skills in young children with autism spectrum disorder (ASD). Sixty preschool-aged children with ASD were assessed using measures of joint attention, imitation, toy play, language, and communication ability. Two skills, initiating protodeclarative joint attention and immediate imitation, were most strongly associated with language ability at age 3-4 years, whereas toy play and deferred imitation were the best predictors of rate of communication development from age 4 to 6.5 years. The implications of these results for understanding the nature and course of language development in autism and for the development of targeted early interventions are discussed. (+info)
Functional genetic analysis of mutations implicated in a human speech and language disorder.
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Mutations in the FOXP2 gene cause a severe communication disorder involving speech deficits (developmental verbal dyspraxia), accompanied by wide-ranging impairments in expressive and receptive language. The protein encoded by FOXP2 belongs to a divergent subgroup of forkhead-box transcription factors, with a distinctive DNA-binding domain and motifs that mediate hetero- and homodimerization. Here we report the first direct functional genetic investigation of missense and nonsense mutations in FOXP2 using human cell-lines, including a well-established neuronal model system. We focused on three unusual FOXP2 coding variants, uniquely identified in cases of verbal dyspraxia, assessing expression, subcellular localization, DNA-binding and transactivation properties. Analysis of the R553H forkhead-box substitution, found in all affected members of a large three-generation family, indicated that it severely affects FOXP2 function, chiefly by disrupting nuclear localization and DNA-binding properties. The R328X truncation mutation, segregating with speech/language disorder in a second family, yields an unstable, predominantly cytoplasmic product that lacks transactivation capacity. A third coding variant (Q17L) observed in a single affected child did not have any detectable functional effect in the present study. In addition, we used the same systems to explore the properties of different isoforms of FOXP2, resulting from alternative splicing in human brain. Notably, one such isoform, FOXP2.10+, contains dimerization domains, but no DNA-binding domain, and displayed increased cytoplasmic localization, coupled with aggresome formation. We hypothesize that expression of alternative isoforms of FOXP2 may provide mechanisms for post-translational regulation of transcription factor function. (+info)
Individual differences in anatomy predict reading and oral language impairments in children.
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Developmental dyslexia (DD) and specific language impairment (SLI) are disorders of language that differ in diagnostic criteria and outcome. DD is defined by isolated reading deficits. SLI is defined by poor receptive and expressive oral language skills. Reading deficits, although prevalent, are not necessary for the diagnosis of SLI. An enduring question is whether these two disorders are qualitatively different or simply differ quantitatively along a dimension of severity. Here we address this problem by examining neuroanatomical correlates of reading and language in children with learning disabilities. We asked whether a quantitative anatomical risk index derived from previous work could predict behavioural profiles in a heterogeneous sample of 14 boys and 8 girls (11-16 years of age) with reading and language impairments. The results confirmed our predictions that (i) children with relatively smaller and symmetrical brain structures (negative risk indices) would have the severe comprehension impairments typical of SLI; (ii) children with larger, asymmetrical brain structures (positive risk indices) would have poor word reading in the presence of relatively preserved comprehension, a profile typical of DD; and (iii) the best performance would be seen in children with anatomical risk indices near zero (normal anatomy). Also, in confirmation of previous work, rapid automatic naming was not predicted by the anatomical risk index, but by anatomical measures derived from the frontal lobes. These results highlight the key significance of comprehension deficits in distinguishing DD from SLI. Reading impaired children with and without comprehension deficits appear to occupy neuroanatomical domains on the opposite sides of normal. (+info)
The development of oral motor control and language.
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Motor control has long been associated with language skill, in deficits, both acquired and developmental, and in typical development. Most evidence comes from limb praxis however; the link between oral motor control and speech and language has been neglected, despite the fact that most language users talk with their mouths. Oral motor control is affected in a variety of developmental disorders, including Down syndrome. However, its development is poorly understood. We investigated oral motor control in three groups: adults with acquired aphasia, individuals with developmental dysphasia, and typically developing children. In individuals with speech and language difficulties, oral motor control was impaired. More complex movements and sets of movements were even harder for individuals with language impairments. In typically developing children (21-24 months), oral motor control was found to be related to language skills. In both studies, a closer relationship was found between language and complex oral movements than simple oral movements. This relationship remained when the effect of overall cognitive ability was removed. Children who were poor at oral movements were not good at language, although children who were good at oral movements could fall anywhere on the distribution of language abilities. Oral motor skills may be a necessary precursor for language skills. (+info)
Simultaneous treatment of grammatical and speech-comprehensibility deficits in children with Down syndrome.
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Children with Down syndrome often display speech-comprehensibility and grammatical deficits beyond what would be predicted based upon general mental age. Historically, speech-comprehensibility has often been treated using traditional articulation therapy and oral-motor training so there may be little or no coordination of grammatical and speech-comprehensibility treatment. The purpose of this paper is to provide the rationale for and preliminary evidence in support of integrating speech and grammatical intervention using a type of recast treatment in six children with Down syndrome. Speech-comprehensibility and MLU growth in generalisation sessions occurred in 4/6 and 5/6 participants, respectively. Using multiple baseline design logic, two of these participants showed evidence of treatment effects on speech-comprehensibility and two in MLU in generalisation sessions, respectively. The study constitutes a conservative test of the intervention effects for reasons that are discussed. The theoretical and applied significance of these findings are discussed. (+info)
Cortical dysplasia of the left temporal lobe might explain severe expressive-language delay in patients with duplication of the Williams-Beuren locus.
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We report on a new duplication case of 7q11.23, reciprocal of the Williams-Beuren (WB) deletion. The patient, a 13-year-old girl, was ascertained within an array-CGH screening of patients with epilepsy and neuronal migration defects. Similarly to the first reported patient, she showed serious difficulties in expressive language in the absence of severe mental retardation and marked dysmorphic features. Magnetic resonance imaging (MRI) of the brain revealed an abnormal development of the cerebral cortex in the left temporal lobe, which showed a simplified gyral pattern, and increased cortical thickness. This finding, which might explain poor language development, suggests that the WB critical region might harbour a dosage-sensitive gene controlling the molecular machinery of neuronal migration, with regional specificity and lateralization. It will be important to confirm our findings in newly diagnosed patients with dup(7)(q11.23). We expect to detect many more patients with the same duplication using widespread clinical implementation of high-resolution genome analysis. (+info)
Dynamic assessment of school-age children's narrative ability: an experimental investigation of classification accuracy.
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Two experiments examined reliability and classification accuracy of a narration-based dynamic assessment task. PURPOSE: The first experiment evaluated whether parallel results were obtained from stories created in response to 2 different wordless picture books. If so, the tasks and measures would be appropriate for assessing pretest and posttest change within a dynamic assessment format. The second experiment evaluated the extent to which children with language impairments performed differently than typically developing controls on dynamic assessment of narrative language. METHOD: In the first experiment, 58 1st- and 2nd-grade children told 2 stories about wordless picture books. Stories were rated on macrostructural and microstructural aspects of language form and content, and the ratings were subjected to reliability analyses. In the second experiment, 71 children participated in dynamic assessment. There were 3 phases: a pretest phase, in which children created a story that corresponded to 1 of the wordless picture books from Experiment 1; a teaching phase, in which children attended 2 short mediation sessions that focused on storytelling ability; and a posttest phase, in which children created a story that corresponded to a second wordless picture book from Experiment 1. Analyses compared the pretest and posttest stories that were told by 2 groups of children who received mediated learning (typical and language impaired groups) and a no-treatment control group of typically developing children from Experiment 1. RESULTS: The results of the first experiment indicated that the narrative measures applied to stories about 2 different wordless picture books had good internal consistency. In Experiment 2, typically developing children who received mediated learning demonstrated a greater amount of pretest to posttest change than children in the language impaired and control groups. Classification analysis indicated better specificity and sensitivity values for measures of response to intervention (modifiability) and posttest storytelling than for measures of pretest storytelling. Observation of modifiability was the single best indicator of language impairment. Posttest measures and modifiability together yielded no misclassifications. CONCLUSION: The first experiment supported the use of 2 wordless picture books as stimulus materials for collecting narratives before and after mediation within a dynamic assessment paradigm. The second experiment supported the use of dynamic assessment for accurately identifying language impairments in school-age children. (+info)
Effect of sentence length and complexity on working memory performance in Hungarian children with specific language impairment (SLI): A cross-linguistic comparison.
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BACKGROUND: English-speaking children with specific language impairment (SLI) perform more poorly than their typically developing peers in verbal working memory tasks where processing and storage are simultaneously required. Hungarian is a language with a relatively free word order and a rich agglutinative morphology. AIMS: To examine the effect of linguistic structure on working memory performance. It was examined whether syntactic complexity has a larger impact on working memory performance than sentence length in Hungarian-speaking children, similar to the findings in English speaking children. METHODS & PROCEDURES: In Experiment 1, performance accuracy was measured with two linguistic span tasks that included stimuli with varying sentence length and syntactic complexity. Experiment 2 examined the impact of sentence length and morphological complexity on working memory performance. OUTCOMES & RESULTS: Children with SLI performed more poorly than their age-matched peers in all working memory tasks. Their error patterns differed from those of children with typical language development. Children with SLI produced a high number of interference errors that indicate poor executive functions. The findings were compared with previous results of English-speaking children. Complexity affected working memory performance accuracy differently across languages. In English, it was the increase of syntactic complexity that resulted in a decrease in performance accuracy, whereas in Hungarian, it was the morphological complexity that had a large impact on working memory performance. CONCLUSIONS: Working memory performance depends on the linguistic characteristics of the language tested. In both English- and Hungarian-speaking children, complexity has a larger effect on verbal working memory performance than the length of the stimuli. However, complexity affects working memory performance accuracy differently across languages. (+info)