Prevalence of specific language impairment in kindergarten children

Predicting language development at age 18 months: data from the Norwegian Mother and Child Cohort Study

OBJECTIVES

This study investigated predictors of delayed language development at 18 months of age in a large population cohort of Norwegian toddlers.

METHODS

Data were analyzed on 42,107 toddlers. Language outcome at age 18 months was measured using a standard parent report instrument, the Ages and Stages Questionnaire, communication scale. Confirmatory factor analysis was conducted on the Ages and Stages Questionnaire items. A theoretically derived set of child, family, and environmental risk factors were used to predict delayed language development at age 18 months using Generalized Estimating Equation.

RESULTS

A number of child factors, including being a boy, low birth weight or gestational age, or a multiple birth child were all significantly associated with low scores on the language outcome at age 18 months. Maternal distress/depression and low maternal education, having older siblings, or a non-Norwegian language background also predicted low scores on the language outcome at age 18 months. Overall, estimated variance in language outcome explained by the model was 4% to 7%.

CONCLUSIONS

A combination of early neurobiological and genetic factors (e.g., male gender, birth weight, and prematurity) and concurrent family variables (e.g., maternal distress/depression) were associated with slower language development at age 18 months. This finding replicated previous research conducted on slightly older language-delayed 2 year olds but also detected the importance of factors related to family resources for the first time in this younger age group. Despite this finding, most of the variability in language performance in this cohort of 18 month olds remained unexplained by the comprehensive set of purported risk factors.

Other impairment associated with developmental language delay in preschool-aged children

The aim of this study was to investigate developmental impairment in several domains that might be associated with developmental language delay. The records of 56 preschool children with developmental language delay and 31 nonimpaired children were reviewed. Children with language delay were more likely than those in the nonimpaired group to have cognitive developmental delay (Mental Development Index < 70) (P < .001) and gross and fine motor delay (gross: 28 [50%] versus 5 [16%], P = .002; fine: 34 [62%] versus 11 [35%], P = .02). Children with language delay were significantly more likely to have impairment than were nonimpaired children in gross motor, fine motor, comprehension-conceptual and personal-social (P = .01, P = .02, P = .01, P = .02, respectively) functional domains. Our findings indicate that preschool children with language delay have wide-ranging difficulties in development and function.

Exploring the outcomes of a novel computer-assisted treatment program targeting expressive-grammar deficits in preschoolers with SLI

PURPOSE

The impact of a newly designed computer-assisted treatment (C-AT) program, My Sentence Builder, for the remediation of expressive-grammar deficits in children with specific language impairment (SLI) was explored. This program was specifically designed with features to directly address expressive-grammar difficulties, thought to be associated with hypothesized deficits in verbal working memory (VWM).

METHOD

Thirty-four preschoolers with deficits in expressive-grammar morphology participated. Using the randomization procedure of consecutive sampling, participants were recruited. Twenty-two participants were consecutively assigned to one of two treatment groups, C-AT or non C-AT (nC-AT). The nC-AT utilized conventional language stimulation procedures containing features which have been traditionally used to address expressive-grammar deficits. A group of equivalent children awaiting treatment and chosen from the same sample of children as the treatment participants served as a control group. Blind assessments of outcomes were completed pre-, post-, and 3-months post-treatment in a formal and informal context.

RESULTS

C-AT and nC-AT participants significantly outperformed controls pre-to-post to 3-months post-treatment in both assessment contexts. No significant differences in treatment gains were found between C-AT and nC-AT.

CONCLUSION

Results suggested that treatments designed to directly address expressive-grammar deficits were better than no treatment for preschool SLI. Further, use of a C-AT program may be another feasible treatment method for this disorder population.

LEARNING OUTCOMES

As a result of this activity, the reader will recognize that: (1) expressive-grammar treatment is better than no treatment for immediate and continued language growth, (2) use of a C-AT program containing specific features designed to directly address expressive-grammar deficits is another viable, but not necessarily a better treatment option for the remediation of expressive-grammar deficits in preschool children with SLI, and (3) different outcome contexts yield distinct yet equally important findings about growth in children's expressive-grammar skills with treatment.

Sensitivity and specificity of French language and processing measures for the identification of primary language impairment at age 5

PURPOSE

Research on the diagnostic accuracy of different language measures has focused primarily on English. This study examined the sensitivity and specificity of a range of measures of language knowledge and language processing for the identification of primary language impairment (PLI) in French-speaking children. Because of the lack of well-documented language measures in French, it is difficult to accurately identify affected children, and thus research in this area is impeded.

METHOD

The performance of 14 monolingual French-speaking children with confirmed, clinically identified PLI (M = 61.4 months of age, SD = 7.2 months) on a range of language and language processing measures was compared with the performance of 78 children with confirmed typical language development (M age = 58.9 months, SD = 5.7). These included evaluations of receptive vocabulary, receptive grammar, spontaneous language, narrative production, nonword repetition, sentence imitation, following directions, rapid automatized naming, and digit span. Sensitivity, specificity, and likelihood ratios were determined at 3 cutoff points: (a) -1 SD, (b) -1.28 SD, and (b) -2 SD below mean values. Receiver operator characteristic curves were used to identify the most accurate cutoff for each measure.

RESULTS

Significant differences between the PLI and typical language development groups were found for the majority of the language measures, with moderate to large effect sizes. The measures differed in their sensitivity and specificity, as well as in which cutoff point provided the most accurate decision. Ideal cutoff points were in most cases between the mean and -1 SD. Sentence imitation and following directions appeared to be the most accurate measures.

CONCLUSIONS

This study provides evidence that standardized measures of language and language processing provide accurate identification of PLI in French. The results are strikingly similar to previous results for English, suggesting that in spite of structural differences between the languages, PLI in both languages involves a generalized language delay across linguistic domains, which can be identified in a similar way using existing standardized measures.

Communication and cognition profiles in parents of children with nonsyndromic cleft lip and/or palate

The main aim of the study was to ascertain whether parents of children with nonsyndromic cleft lip and/or palate (P-CLP) perform differently than parents of children without CLP (P-control) on a nonword repetition (NWR) test. Given that children with CLP frequently demonstrate communication and cognitive difficulties, a link between NWR performance and group would lend support to a familial risk factor in nonsyndromic CLP. The NWR test, a well-documented assessment to identify language and cognitive impairment, was used, together with a parent questionnaire to gather demographic data and family history information on medical, communication, and/or cognitive difficulties for 260 parents. Group differences on NWR performance and family history of communication and cognition difficulties were not demonstrated. Also, no significant difference on NWR score was seen in the P-CLP group based on child's CLP type. Correlation analysis showed that having more years of schooling, English as the dominant language, living in private housing, and being in skilled occupations were positively correlated to NWR score. Controlling for these known background variables did not alter NWR performance between P-CLP and P-control, however, only years of schooling significantly and consistently predicted NWR performance. Having significantly fewer years of schooling in the P-CLP group could be suggestive of an increased risk of communication and cognitive difficulties these parents face, and the potential difficulties their children with CLP may encounter. These results may inform early and rigorous intervention strategies for children with CLP.

A longitudinal study of behavioral, emotional and social difficulties in individuals with a history of specific language impairment (SLI)

Children with specific language impairment (SLI) have often been reported to have associated behavioral, emotional and social difficulties. Most previous studies involve observations at a single time point, or cross sectional designs, and longitudinal evidence of the developmental trajectories of particular difficulties is limited. The Strengths and Difficulties Questionnaire was used to measure behavioral (hyperactivity and conduct), emotional and social (peer) problems in a sample of individuals with a history of SLI at four time points from childhood (age 7) to adolescence (age 16). A decrease in behavioral and emotional problems was observed from childhood to adolescence, although emotional problems were still evident in adolescence. In contrast, there was an increase in social problems. Reading skills and expressive language were related only to behavioral problems. Pragmatic abilities were related to behavioral, emotional and social difficulties. As a group, those with a history of SLI have poorer long term social and, to a lesser extent, emotional outcomes. In contrast, behavioral difficulties appear to decrease to normative levels by adolescence. Different aspects of early language abilities and reading skills exert different types and degrees of influence on behavioral, emotional and social difficulties.

LEARNING OUTCOMES

Readers will be able to: (1) understand the types of behavioral, emotional and social difficulties present in individuals with a history of SLI; (2) be familiar with the developmental trajectory of these difficulties from childhood to adolescence; and (3) understand the relationships between behavioral, emotional and social difficulties and early language and literacy ability.

Co-morbidity of autism and SLI: kinds, kin and complexity

There has been a long-standing interest in the relationship between specific language impairment (SLI) and autism spectrum disorder (ASD). In the last decade Tager-Flusberg and colleagues have proposed that this relationship consists of a partial overlap between the two. Therefore, among children with ASD there exists a subgroup who have SLI and ASD which has been called 'ALI'. Tager-Flusberg's laboratory has presented several papers showing similar language profiles and brain structure abnormalities in both SLI and ALI. Others (Bishop, Whitehouse, Botting, Williams) have been less convinced that these ALI children have both ASD and SLI. Although they generally agree that the two groups are grossly similar, careful inspection of the data shows that there are differences. I will argue that many of the problems in this debate stem from a view of SLI that represents a particular kind of language learner and therefore a particular and unique profile can be assumed. I argue for recognizing that SLI is not likely to be a unique kind of language learner. Many of the features reported to be characteristic of SLI are also found in other forms of neurodevelopmental disorders. Other features are the outgrowth of studying clinically identified children with SLI and thus the profile appears to reflect biases and practices in the clinical service system. As a result it may be more reasonable to conclude that there is a large group of children with ASD who have poor language skills. The question then remains why are there so many children with ASD who also have poor language? There are several factors that collectively are strong candidates for answers to this question.

Replication of CNTNAP2 association with nonword repetition and support for FOXP2 association with timed reading and motor activities in a dyslexia family sample

Two functionally related genes, FOXP2 and CNTNAP2, influence language abilities in families with rare syndromic and common nonsyndromic forms of impaired language, respectively. We investigated whether these genes are associated with component phenotypes of dyslexia and measures of sequential motor ability. Quantitative transmission disequilibrium testing (QTDT) and linear association modeling were used to evaluate associations with measures of phonological memory (nonword repetition, NWR), expressive language (sentence repetition), reading (real word reading efficiency, RWRE; word attack, WATT), and timed sequential motor activities (rapid alternating place of articulation, RAPA; finger succession in the dominant hand, FS-D) in 188 family trios with a child with dyslexia. Consistent with a prior study of language impairment, QTDT in dyslexia showed evidence of CNTNAP2 single nucleotide polymorphism (SNP) association with NWR. For FOXP2, we provide the first evidence for SNP association with component phenotypes of dyslexia, specifically NWR and RWRE but not WATT. In addition, FOXP2 SNP associations with both RAPA and FS-D were observed. Our results confirm the role of CNTNAP2 in NWR in a dyslexia sample and motivate new questions about the effects of FOXP2 in neurodevelopmental disorders.

Identification of adults with developmental language impairments

PURPOSE

To assess the utility of a wide range of language measures (phonology, morphology, syntax, and semantics) for the identification of adults with developmental language impairment.

METHOD

Measures were administered to 3 groups of adults, each representing a population expected to demonstrate high levels of language impairment, and to matched control groups.

RESULTS

Three measures were the strongest contributors to identification of language impairment in the 3 groups of adults. These measures, combined, maximized identification of members of the clinical groups as having impaired language (sensitivity) and members of the control groups as having typical language (specificity).

CONCLUSION

This suggests that a relatively brief battery could have utility for identifying developmental language impairment during the adult years.

Psycholinguistic profiling differentiates specific language impairment from typical development and from attention-deficit/hyperactivity disorder

PURPOSE

Practitioners must have confidence in the capacity of their language measures to discriminate developmental language disorders from typical development and from other common disorders. In this study, psycholinguistic profiles were collected from 3 groups: children with specific language impairment (SLI), children with attention-deficit/hyperactivity disorder (ADHD), and children with typical development (TD). The capacity of different language indices to successfully discriminate SLI cases from TD and ADHD cases was examined through response operating characteristics curves, likelihood ratios, and binary logistic regression.

METHOD

The Test of Early Grammatical Impairment (Rice & Wexler, 2001a), Dollaghan and Campbell's (1998) nonword repetition task, Redmond's (2005) sentence recall task, and the Test of Narrative Language (Gillam & Pearson, 2004) were administered to 60 children (7-8 years of age).

RESULTS

Diagnostic accuracy was high for all 4 psycholinguistic measures, although modest reductions were observed with the SLI versus ADHD discriminations. Classification accuracy associated with using the Test of Early Grammatical Impairment and the Sentence Recall task was equivalent to using all 4 measures.

IMPLICATIONS

Outcomes confirmed and extended previous investigations, documenting high levels of diagnostic integrity for these particular indices and supporting their incorporation into eligibility decisions, differential diagnosis, and the identification of comorbidity.

The influence of neighborhood density and word frequency on phoneme awareness in 2nd and 4th grades

PURPOSE

The purpose of this study was to test the hypothesis that two lexical characteristics - neighborhood density and word frequency - interact to influence performance on phoneme awareness tasks.

METHODS

Phoneme awareness was examined in a large, longitudinal dataset of 2nd and 4th grade children. Using linear logistic test model, the relation between words' neighborhood density, word frequency, and phoneme awareness performance was examined across grades while co-varying type and place of deletion.

RESULTS

A predicted interaction was revealed: words from dense neighborhoods or those with high frequency were more likely to yield correct phoneme awareness responses across grades.

CONCLUSIONS

Findings support an expansion of the lexical restructuring model to include interactions between neighborhood density and word frequency to account for phoneme awareness.

LEARNING OUTCOMES

The reader will be able to (1) describe the lexical restructuring model; (2) define neighborhood density; (3) define word frequency; (4) identify how these variables interact to impact phoneme awareness performance; (5) identify ways in which future clinical practice may be impacted by the study's findings.

The Genetics of Autism

This chapter is written to make the fast-paced, expanding field of the genetics of autism accessible to those practitioners who help children with autism. New genetic knowledge and technology have quickly developed over the past 30 years, particularly within the past decade, and have made many optimistic about our ability to explain autism. Among these advances include the sequencing of the human genome (Lander et al., 2001) and the identification of common genetic variants via the HapMap project (International HapMap Consortium, 2005), and the development of cost-efficient genotyping and analysis technologies (Losh, Sullivan, Trembath, & Piven, 2008). Improvement in technology has led to improved visualization of chromosomal abnormality down to the molecular level. The four most common syndromes associated with autism include fragile X syndrome, tuberous sclerosis, 15q duplications, and untreated phenylketonuria (PKU; Costa e Silva, 2008). FXS and 15q duplications are discussed within the context of cytogenetics. TSC is illustrated within the description of linkage analysis.

Mothers' autobiographical memory and book narratives with children with specific language impairment

This study examined the role that mothers' scaffolding plays in the autobiographical memory (AM) and storybook narratives of children with specific language impairment (SLI). Seven 4-5-year-old children and their mothers co-constructed narratives in both contexts. We also compared children's narratives with mothers to their narratives with an experimenter. Narratives were assessed in terms of narrative style (i.e., elaborativeness) and topic control. Mothers' elaborative and repetitive questions during AM and book narratives were related to children's elaborations, whereas mothers' elaborative and repetitive statements were not. Mothers produced more topic-controlling utterances than children in both contexts; however, both mothers and children provided proportionally more information in the book context. Additionally, children were more elaborative with mothers compared to an experimenter.

LEARNING OUTCOMES

Readers will be able to: (1) understand the importance of mother-child narratives for both typical and clinical populations; (2) understand how mother-child autobiographical memory and storybook narratives may differ between typical and clinical populations; and (3) consider the implications for designing narrative intervention studies for language impaired children.

Longitudinal patterns of behaviour problems in children with specific speech and language difficulties: Child and contextual factors

BACKGROUND

The purpose of this study was to examine the stability of behavioural, emotional and social difficulties (BESD) in children with specific speech and language difficulties (SSLD), and the relationship between BESD and the language ability.

METHODS

A sample of children with SSLD were assessed for BESD at ages 8, 10 and 12 years by both teachers and parents. Language abilities were assessed at 8 and 10 years.

RESULTS

High levels of BESD were found at all three ages but with different patterns of trajectories for parents' and teachers' ratings. Language ability predicted teacher- but not parent-rated BESD.

CONCLUSIONS

The study confirms the persistence of high levels of BESD over the period 8-12 years and the continuing comorbidity of BESD and language difficulties but also indicates a complex interaction of within-child and contextual factors over time.

Electrophysiological correlates of rapid auditory and linguistic processing in adolescents with specific language impairment

Brief tonal stimuli and spoken sentences were utilized to examine whether adolescents (aged 14;3-18;1) with specific language impairments (SLI) exhibit atypical neural activity for rapid auditory processing of non-linguistic stimuli and linguistic processing of verb-agreement and semantic constraints. Further, we examined whether the behavioral and electrophysiological indices for rapid auditory processing were correlated with those for linguistic processing. Fifteen adolescents with SLI and 15 adolescents with normal language met strict criteria for displaying consistent diagnoses from kindergarten through the eighth grade. The findings provide evidence that auditory processing for non-linguistic stimuli is atypical in a significant number of adolescents with SLI compared to peers with normal language and indicate that reduced efficiency in auditory processing in SLI is more vulnerable to rapid rates (200ms ISI) of stimuli presentation (indexed by reduced accuracy, a tendency for longer RTs, reduced N100 over right anterior sites, and reduced amplitude P300). Many adolescents with SLI displayed reduced behavioral accuracy for detecting verb-agreement violations and semantic anomalies, along with less robust P600s elicited by verb-agreement violations. The results indicate that ERPs elicited by morphosyntactic aspects of language processing are atypical in many adolescents with SLI. Additionally, correlational analyses between behavioral and electrophysiological indices of processing non-linguistic stimuli and verb-agreement violations suggest that the integrity of neural functions for auditory processing may only account for a small proportion of the variance in morphosyntactic processing in some adolescents.

Beyond capacity limitations II: effects of lexical processes on word recall in verbal working memory tasks in children with and without specific language impairment

PURPOSE

This study investigated the impact of lexical processes on target word recall in sentence span tasks in children with and without specific language impairment (SLI).

METHOD

Participants were 42 children (ages 8;2-12;3 [years;months]): 21 with SLI and 21 typically developing peers matched on age and nonverbal IQ. Children completed a sentence span task in which target words to be recalled varied in word frequency and neighborhood density. Two measures of lexical processes were examined: the number of nontarget competitor words activated during a gating task (lexical cohort competition) and word definitions.

RESULTS

Neighborhood density had no effect on word recall for either group. However, both groups recalled significantly more high- than low-frequency words. Lexical cohort competition and specificity of semantic representations accounted for unique variance in the number of target word recalled in the SLI and chronological age-matched (CA) groups combined.

CONCLUSIONS

Performance on verbal working memory span tasks for both SLI and CA children is influenced by word frequency, lexical cohorts, and semantic representations. Future studies need to examine the extent to which verbal working memory capacity is a cognitive construct independent of extant language knowledge representations.

Cerebellar-dependent delay eyeblink conditioning in adolescents with Specific Language Impairment

Cerebellar impairments have been hypothesized as part of the pathogenesis of Specific Language Impairment (SLI), although direct evidence of cerebellar involvement is sparse. Eyeblink Conditioning (EBC) is a learning task with well documented cerebellar pathways. This is the first study of EBC in affected adolescents and controls. 16 adolescent controls, 15 adolescents with SLI, and 12 adult controls participated in a delay EBC task. Affected children had low general language performance, grammatical deficits but no speech impairments. The affected group did not differ from the control adolescent or control adult group, showing intact cerebellar functioning on the EBC task. This study did not support cerebellar impairment at the level of basic learning pathways as part of the pathogenesis of SLI. Outcomes do not rule out cerebellar influences on speech impairment, or possible other forms of cerebellar functioning as contributing to SLI.

Emergent literacy profiles of preschool-age children with specific language impairment

The primary aim of the present study was to explore the heterogeneity of emergent literacy skills among preschool-age children with specific language impairment (SLI) through examination of profiles of performance. Fifty-nine children with SLI were assessed on a battery of emergent literacy skills (i.e., alphabet knowledge, print concepts, emergent writing, rhyme awareness) and oral language skills (i.e., receptive/expressive vocabulary and grammar). Cluster analysis techniques identified three emergent literacy profiles: (1) Highest Emergent Literacy, Strength in Alphabet Knowledge; (2) Average Emergent Literacy, Strength in Print Concepts; and (3) Lowest Emergent Literacy across Skills. After taking into account the contribution of child age, receptive and expressive language skills made a small contribution to the prediction of profile membership. The present findings, which may be characterized as exploratory given the relatively modest sample size, suggest that preschool-age children with SLI display substantial individual differences with regard to their emergent literacy skills and that these differences cannot be fully determined by children's age or oral language performance. Replication of the present findings with a larger sample of children is needed.

Predicting language outcomes at 4 years of age: findings from Early Language in Victoria Study

OBJECTIVE

To quantify the contributions of child, family, and environmental predictors to language ability at 4 years.

METHODS

A longitudinal study was performed with a sample of 1910 infants recruited at 8 months in Melbourne, Australia. Predictors were child gender, prematurity, birth weight and order, multiple birth, socioeconomic status, maternal mental health, vocabulary, education, and age at child's birth, non-English-speaking background, and family history of speech/language difficulties. Outcomes were Clinical Evaluation of Language Fundamentals-Preschool, language scores, low language status (scores >1.25 SDs below the mean), and specific language impairment (SLI) (scores >1.25 SDs below the mean for children with normal nonverbal performance).

RESULTS

A total of 1596 children provided outcome data. Twelve baseline predictors explained 18.9% and 20.9% of the variation in receptive and expressive scores, respectively, increasing to 23.6% and 30.4% with the addition of late talking status at age 2. A total of 20.6% of children (324 of 1573 children) met the criteria for low language status and 17.2% (251 of 1462 children) for SLI. Family history of speech/language problems and low maternal education levels and socioeconomic status predicted adverse language outcomes. The combined predictors discriminated only moderately between children with and without low language levels or SLIs (area under the curve: 0.72-0.76); this improved with the addition of late talking status (area under the curve: 0.78-0.84).

CONCLUSIONS

Measures of social disadvantage helped explain more variation in outcomes at 4 years than at 2 years, but ability to predict low language status and SLI status remained limited.

Intervention for mixed receptive-expressive language impairment: a review

Studies indicate that language impairment that cannot be accounted for by factors such as below-average non-verbal ability, hearing impairment, behaviour or emotional problems, or neurological impairments affects some 6% of school-age children. Language impairment with a receptive language component is more resistant to intervention than specific expressive or phonological delays, and carries a greater risk of comorbid behavioural difficulties as well as adverse outcomes for language development and academic progress. This paper considers underlying explanations that may account for receptive-expressive language impairment. It also reviews evidence for the effectiveness of intervention from theory and recent systematic reviews, trials, and speech and language therapy practice.

Sibling recurrence and the genetic epidemiology of autism

OBJECTIVE

Although the symptoms of autism exhibit quantitative distributions in nature, estimates of recurrence risk in families have never previously considered or incorporated quantitative characterization of the autistic phenotype among siblings.

METHOD

The authors report the results of quantitative characterization of 2,920 children from 1,235 families participating in a national volunteer register, with at least one child clinically affected by an autism spectrum disorder and at least one full biological sibling.

RESULTS

A traditionally defined autism spectrum disorder in an additional child occurred in 10.9% of the families. An additional 20% of nonautism-affected siblings had a history of language delay, one-half of whom exhibited autistic qualities of speech. Quantitative characterization using the Social Responsiveness Scale supported previously reported aggregation of a wide range of subclinical (quantitative) autistic traits among otherwise unaffected children in multiple-incidence families and a relative absence of quantitative autistic traits among siblings in single-incidence families. Girls whose standardized severity ratings fell above a first percentile severity threshold (relative to the general population distribution) were significantly less likely to have elicited community diagnoses than their male counterparts.

CONCLUSIONS

These data suggest that, depending on how it is defined, sibling recurrence in autism spectrum disorder may exceed previously published estimates and varies as a function of family type. The results support differences in mechanisms of genetic transmission between simplex and multiplex autism and advance current understanding of the genetic epidemiology of autism spectrum conditions.

Narrative abilities in monolingual and dual language learning children with specific language impairment

PURPOSE

The aim of this study was to compare narrative abilities in children with specific language impairment (SLI) who are monolingual and those who are dual language learners.

METHOD

The participants were 26 children with SLI, 14 monolingual English speakers and 12 dual language learners. The dual language learners were English dominant and spoke a variety of other languages in the home. The two SLI groups were compared using standardized tests and measures from two narrative samples.

RESULTS

Compared to the monolingual children, the dual language learners achieved lower scores on standardized tests of morphosyntax but not on measures of language form derived from the narrative samples. Both groups achieved below average scores on productivity, narrative structure, literate language, and language form measures from the narrative samples.

CONCLUSION

The data suggest that narrative samples can be a sensitive way to assess the language skills of dual language learners with specific language impairment. Furthermore, the findings are consistent with the position that English standardized tests may be a biased assessment measure when used with dual language learners, particularly for the assessment of expressive morphosyntactic skills.

LEARNING OUTCOMES

Readers will be able to (1) describe the narrative abilities of typically developing dual language learners; (2) describe similarities between the narrative abilities of children with SLI who are monolingual and dual language learners; (3) identify ways to analyses narratives at a variety of levels.

Bilingual children with primary language impairment: issues, evidence and implications for clinical actions

A clear understanding of how to best provide clinical serves to bilingual children with suspected or confirmed primary language impairment (PLI) is predicated on understanding typical development in dual-language learners as well as the PLI profile. This article reviews general characteristics of children learning two languages, including three that challenge the diagnosis and treatment of PLI; uneven distribution of abilities in the child's two languages, cross-linguistic associations within bilingual learners, and individual variation in response to similar social circumstances. The diagnostic category of PLI (also referred to in the literature as specific language impairment or SLI) is described with attention to how language impairment, in the face of otherwise typical development, manifests in children learning two languages. Empirical evidence related to differential diagnosis of PLI in bilingual children is then reviewed and issues related to the generalization of treatment gains in dual-language learners with PLI are introduced.

LEARNING OUTCOMES

As a result of this activity, the careful reader will be able to (1) describe general characteristics of typically developing dual-language learners, (2) explain how primary language impairment (PLI) manifests in bilingual children, and (3) identify key clinical issues and approaches to assessment and treatment on bilingual PLI.

Increasing genotype-phenotype model determinism: application to bivariate reading/language traits and epistatic interactions in language-impaired families

While advances in network and pathway analysis have flourished in the era of genome-wide association analysis, understanding the genetic mechanism of individual loci on phenotypes is still readily accomplished using genetic modeling approaches. Here, we demonstrate two novel genotype-phenotype models implemented in a flexible genetic modeling platform. The examples come from analysis of families with specific language impairment (SLI), a failure to develop normal language without explanatory factors such as low IQ or inadequate environment. In previous genome-wide studies, we observed strong evidence for linkage to 13q21 with a reading phenotype in language-impaired families. First, we elucidate the genetic architecture of reading impairment and quantitative language variation in our samples using a bivariate analysis of reading impairment in affected individuals jointly with language quantitative phenotypes in unaffected individuals. This analysis largely recapitulates the baseline analysis using the categorical trait data (posterior probability of linkage (PPL) = 80%), indicating that our reading impairment phenotype captured poor readers who also have low language ability. Second, we performed epistasis analysis using a functional coding variant in the brain-derived neurotrophic factor (BDNF) gene previously associated with reduced performance on working memory tasks. Modeling epistasis doubled the evidence on 13q21 and raised the PPL to 99.9%, indicating that BDNF and 13q21 susceptibility alleles are jointly part of the genetic architecture of SLI. These analyses provide possible mechanistic insights for further cognitive neuroscience studies based on the models developed herein.

Comprehension of inferences in discourse processing by adolescents with and without language impairment

PURPOSE

This study investigated inference construction within spoken narratives in adolescents with varying cognitive and language abilities, using W. Kintsch's (1988) construction-integration model as a framework. The role of working memory in inference construction was examined along with language and nonverbal cognition.

METHOD

Participants were 527 eighth-grade students in 4 diagnostic groups: normal language (NL), low cognitive (LC), specific language impairment (SLI), and nonspecific language impairment (NLI). Participants answered premise and inference questions based on adjacent and distant information.

RESULTS

Distant inferences were significantly more difficult than were adjacent inferences. When controlling for premise accuracy, the NL group performed significantly better than each of the other groups on distant inferences. The LC group demonstrated significantly higher accuracy on distant inferences than did the NLI group. Regression analyses revealed that performance on a verbal working memory measure predicted unique variance in distant inference accuracy beyond that accounted for by measures of language and nonverbal cognition.

CONCLUSIONS

Understanding implicit information, particularly when linking distant information, is difficult for adolescents who are deficient in language comprehension, verbal working memory skills, and/or general world knowledge.

Overlaps between autism and language impairment: phenomimicry or shared etiology?

Traditionally, autistic spectrum disorder (ASD) and specific language impairment (SLI) are regarded as distinct conditions with separate etiologies. Yet these disorders co-occur at above chance levels, suggesting shared etiology. Simulations, however, show that additive pleiotropic genes cannot account for observed rates of language impairment in relatives, which are higher for probands with SLI than for those with ASD + language impairment. An alternative account is in terms of 'phenomimicry', i.e., language impairment in comorbid cases may be a consequence of ASD risk factors, and different from that seen in SLI. However, this cannot explain why molecular genetic studies have found a common risk genotype for ASD and SLI. This paper explores whether nonadditive genetic influences could account for both family and molecular findings. A modified simulation involving G x G interactions obtained levels of comorbidity and rates of impairment in relatives more consistent with observed values. The simulations further suggest that the shape of distributions of phenotypic trait scores for different genotypes may provide evidence of whether a gene is involved in epistasis.

A longitudinal investigation of early reading and language skills in children with poor reading comprehension

BACKGROUND

Poor comprehenders have difficulty comprehending connected text, despite having age-appropriate levels of reading accuracy and fluency. We used a longitudinal design to examine earlier reading and language skills in children identified as poor comprehenders in mid-childhood.

METHOD

Two hundred and forty-two children began the study at age 5. Further assessments of language and reading skill were made at 5.5, 6, 7 and 8 years. At age 8, fifteen children met criteria for being a poor comprehender and were compared to 15 control children both concurrently and prospectively.

RESULTS

Poor comprehenders showed normal reading accuracy and fluency at all ages. Reading comprehension was poor at each time point and, notably, showed minimal increases in raw score between 6 and 8 years. Phonological skills were generally normal throughout, but mild impairments in expressive and receptive language, listening comprehension and grammatical understanding were seen at all ages.

CONCLUSIONS

Children identified as poor comprehenders at 8 years showed the same reading profile throughout earlier development. Their difficulties with the non-phonological aspects of oral language were present at school entry and persisted through childhood, showing that the oral language weaknesses seen in poor comprehenders in mid-childhood are not a simple consequence of their reading comprehension impairment.

Perinatal exposure to hazardous air pollutants and autism spectrum disorders at age 8

BACKGROUND

Hazardous air pollutants are plausible candidate exposures for autism spectrum disorders. They have been explored in recent studies for their role in the development of these disorders.

METHODS

We used a prevalent case-control design to screen perinatal exposure to 35 hazardous air pollutants for further investigation in autism etiology. We included 383 children with autism spectrum disorders and, as controls, 2,829 children with speech and language impairment. All participants were identified from the records-based surveillance of 8-year-old children conducted by the Autism and Developmental Disabilities Monitoring Network in North Carolina (for children born in 1994 and 1996) and West Virginia (born in 1992 and 1994). Exposures to ambient concentrations of metal, particulate, and volatile organic air pollutants in the census tract of the child's birth residence were assigned from the 1996 National Air Toxics Assessment annual-average model. We estimated odds ratios (ORs) for autism spectrum disorders and corresponding 95% confidence intervals (CIs), comparing across the 20th and 80th percentiles of log-transformed hazardous air pollutant concentration among the selected controls, using semi-Bayes logistic models and adjusting for sampling variables (surveillance year and state), a priori demographic confounders from the birth certificate and census, and covarying air pollutants.

RESULTS

We estimated many near-null ORs, including those for metals, established human neurodevelopmental toxicants, and several pollutants that were elevated in a similar study in California. Hazardous air pollutants with more precise and elevated OR estimates included methylene chloride, 1.4 (95% CI = 0.7-2.5), quinoline, 1.4 (1.0-2.2), and styrene, 1.8 (1.0-3.1).

CONCLUSIONS

Our screening design was limited by exposure misclassification of air pollutants and the use of an alternate developmental disorder as the control group, both of which may have biased results toward the null. Despite these limitations, methylene chloride, quinoline, and styrene emerged (based on this analysis and prior epidemiologic evidence) as candidates that warrant further investigation for a possible role in autism etiology.

Etiologies and molecular mechanisms of communication disorders

Quantitative behavioral genetic studies have made it clear that communication disorders such as reading disability, language impairment, and autism spectrum disorders follow some basic principles: (1) complex disorders have complex causes, in which each clinical disorder is influenced by a number of separate genes; and (2) at least some behaviorally related disorders are influenced by the same genes. Recent advances in molecular and statistical methods have confirmed these principles and are now leading to an understanding of the genes that may be involved in these disorders and how their disruption may affect the development of the brain. The prospect is that the genes involved in these disorders will define a network of interacting neurologic functions and that perturbations of different elements of this network will produce susceptibilities for different disorders. Such knowledge would clarify the underlying deficits in these disorders and could lead to revised diagnostic conceptions. However, these goals are still in the future. Identifying the individual genes in such a network is painstaking, and there have been seemingly contradictory studies along the way. Improvements in study design and additional functional analysis of genes are gradually clarifying many of these issues. When combined with careful phenotypic studies, molecular genetic studies have the potential to refine the clinical definitions of communication disorders and influence their remediation.

Is there a sex ratio difference in the familial aggregation of specific language impairment? A meta-analysis

PURPOSE

Specific language impairment (SLI) is known to aggregate in families. Debate exists on whether the male sex presents an additional risk for SLI. This meta-analysis examined whether there is a sex ratio difference in the risk for impairment among family members of an SLI proband and whether this is mediated by assessment method (direct assessment via psychometric tests vs. indirect assessment via questionnaire/interview) or relative type (sibling vs. parent).

METHOD

Twelve studies met inclusion criteria, including 11 parent and 9 sibling samples. Risk ratios, indicating relative risk for language difficulties for males versus females, were calculated as a function of assessment method and relative type.

RESULTS

Direct assessments identified a male predominance of language impairment, with a pooled risk ratio of 1.73 for siblings (95% confidence interval [CI]: 1.20-2.52) and 1.54 for parents (95% CI: 1.14-2.07). No sex differences were observed for studies using indirect testing methods, with mean risk ratios of 1.12 (0.85-1.48) and 1.17 (0.92-1.49) for sibling and parent samples, respectively.

CONCLUSION

A predominance of affected males among family members is observed when using direct assessments only. This finding is interpreted with reference to the strengths and weaknesses of different assessment methodologies and what sex differences may indicate about the biological mechanisms underlying the SLI phenotype.

The language phenotype of children and adolescents with Noonan syndrome

PURPOSE

This study presents an analysis of language skills in individuals with Noonan syndrome (NS), an autosomal dominant genetic disorder. We investigated whether the language impairments affecting some individuals arise from deficits specifically within the linguistic system or whether they are associated with cognitive, perceptual, and motor factors. Comparisons of language abilities among the different NS genotypes were also conducted.

METHOD

Sixty-six children and adolescents with NS were evaluated using standardized speech, language, and literacy assessments. Additional cognitive, perceptual, and motor tasks were administered to examine the relation of these factors to language development. Genotype was noted for those who underwent genetic testing.

RESULTS

Language impairments were more frequent in NS than in the general population and were associated with higher risk for reading and spelling difficulties. Language was significantly correlated with nonverbal cognition, hearing ability, articulation, motor dexterity, and phonological memory. Genotype analyses suggest that the higher performance of SOS1-positive than PTPN11-positive individuals on language tasks was largely mediated by differences in cognitive ability.

CONCLUSIONS

Our results indicate that variation in language skill in NS is closely related to cognitive, perceptual, and motor factors. It does not appear that specific aspects of language are selectively affected in this syndrome.

Social stress in young people with specific language impairment

Social interactions can be a source of social stress for adolescents. Little is known about how adolescents with developmental difficulties, such as specific language impairment (SLI), feel when interacting socially. Participants included 28 adolescents with SLI and 28 adolescents with typical language abilities (TL). Self-report measures of social stress, social skills and social acceptance were obtained. Participants with SLI reported experiencing significantly more social stress than did participants with TL. Both groups judged themselves as having adequate social skills and positive social acceptance. Expressive language ability was negatively associated with social stress, but did not predict social stress when social factors were included in the regression model. Perceived social skills and social acceptance scores predicted social stress, in that poorer scores predicted more social stress. Despite perceiving themselves as having adequate social skills and as being socially accepted, social interactions are nonetheless a source of stress for adolescents with SLI.

Kindergarten attendance may reduce developmental impairments in children: results from the Bavarian Pre-School Morbidity Survey

BACKGROUND

The relative risks and benefits of children attending kindergarten or pre-school remain uncertain and controversial. We used data from the Bavarian Pre-School Morbidity Survey (BPMS) to look at the prevalence of developmental impairments in pre-school children entering primary school and to assess if these were correlated with the duration of kindergarten attendance.

METHODS

We collected data from all school beginners in the district of Dingolfing, Bavaria from 2004 to 2007 (n = 4,005) and utilised a retrospective cross-sectional study design to review the information. The children were assessed for motor, cognitive, language and psychosocial impairments using a standardized medical assessment. Point prevalence of impairments of speech, cognition, motor functioning and psychosocial functioning were compared by chi(2)-test for the variable of time spent in kindergarten.

RESULTS

We detected a high incidence of impairments, with boys showing higher rates than girls in all the areas assessed. Longer length of time spent in kindergarten was associated with reduced rates of motor, cognitive and psychosocial impairments. There was no clear correlation between length of kindergarten attendance and speech disorders.

CONCLUSIONS

Kindergarten attendance may have a positive effect on a number of domains of development including motor, cognitive and psychosocial development, but no significant effect on speech impairments. Implications for public health policies are discussed.

Assessing component language deficits in the early detection of reading difficulty risk

This article focuses on some of the linguistic components that underlie letter-sound decoding skills and reading comprehension: specifically phonology, morphology, and syntax. Many children who have reading difficulties had language deficits that were detectable before they began reading. Early identification of language difficulties will therefore help identify children at risk of reading failure. Using a developmental psycholinguistic framework, the authors provide a model of how syntax, morphology, and phonology break down in children with language impairments. The article reports on a screening test of these language abilities for preschool or young school-aged children that identifies those at risk for literacy problems and in need of further assessment.

Kindergarten predictors of second versus eighth grade reading comprehension impairments

Multiple studies have shown that kindergarten measures of phonological awareness and alphabet knowledge are good predictors of reading achievement in the primary grades. However, less attention has been given to the early predictors of later reading achievement. This study used a modified best-subsets variable-selection technique to examine kindergarten predictors of early versus later reading comprehension impairments. Participants included 433 children involved in a longitudinal study of language and reading development. The kindergarten test battery assessed various language skills in addition to phonological awareness, alphabet knowledge, naming speed, and nonverbal cognitive ability. Reading comprehension was assessed in second and eighth grades. Results indicated that different combinations of variables were required to optimally predict second versus eighth grade reading impairments. Although some variables effectively predicted reading impairments in both grades, their relative contributions shifted over time. These results are discussed in light of the changing nature of reading comprehension over time. Further research will help to improve the early identification of later reading disabilities.

Extending use of the NRT to preschool-age children with and without specific language impairment

PURPOSE

The purpose of this study was to assess the diagnostic accuracy of the Nonword Repetition Test (NRT; Dollaghan & Campbell, 1998) using a sample of 4- and 5-year-olds with and without specific language impairment (SLI) and to evaluate its feasibility for use in universal screening.

METHOD

The NRT was administered to 29 children with SLI and 47 age-matched children with typical development. Diagnostic accuracy was computed using alternative scoring methods, which treated out-of-inventory phonemes either as errors or as unscorable. To estimate accuracy in a universal screening context, the probability of identifying a child at risk for language impairment was computed using the prevalence of SLI (7%) as the base rate.

RESULTS

Diagnostic accuracy was acceptable using both scoring methods. The resulting likelihood ratios (LR+ = 22.66, 19.43; LR- = .05, .05) were similar to those reported for older children. The probability of accurate detection of children with SLI in the general population increased from 7% to 61%. However, this value suggests that many false positives could be expected.

CONCLUSION

The NRT yielded results similar to those reported for older children. However, despite its strengths, the NRT is not sufficient for screening the general population of 4- and 5-year-olds.

Videogames and Young People with Developmental Disorders

Young people with developmental disorders experience difficulties with many cognitive and perceptual tasks, and often suffer social impairments. Yet, like typical youth, many appear to enjoy playing videogames. This review considers the appeal of videogames to individuals with autism spectrum disorders, attention deficit hyperactivity disorder, and specific language impairment. It examines how they respond to the various challenges that play entails with particular reference to sensory, cognitive, and social dimensions. It is argued that research into how these young people engage voluntarily with this dynamic and challenging medium offers great potential to extend our empirical and theoretical understanding of the disorders. Many gaps in our current knowledge are identified and several additional themes for possible future research are proposed.

Memory impairment in children with language impairment

AIM

The aim of this study was to assess whether any memory impairment co-occurring with language impairment is global, affecting both verbal and visual domains, or domain specific.

METHOD

Visual and verbal memory, learning, and processing speed were assessed in children aged 6 years to 16 years 11 months (mean 9 y 9 m, SD 2 y 6 mo) with current, resolved, and no language impairment using the Wide Range Assessment of Memory and Learning (WRAML), a standardized memory and learning test for children, and the Children's Test of Non-Word Repetition (CNRep), a test of phonological short-term memory. Fifty-one children (38 males, 13 females) with current speech and language impairment from 49 families were compared with 13 siblings (11 males, 2 females) with a past history of language impairment and 26 (15 males, 11 females) who had never had language impairment.

RESULTS

Children with current language impairment showed impairment in all verbal memory measures compared with children who had never had language impairment, and these impairments were still evident in children with a past history of learning impairment. Visual memory and learning were not impaired compared with children who had never had language impairment. The severity of verbal memory impairment correlated with the degree of language impairment.

INTERPRETATION

We concluded that in language impairment there is domain specificity of memory impairment affecting verbal processing.

Identifying specific language impairment in deaf children acquiring British Sign Language: implications for theory and practice

This paper presents the first ever group study of specific language impairment (SLI) in users of sign language. A group of 50 children were referred to the study by teachers and speech and language therapists. Individuals who fitted pre-determined criteria for SLI were then systematically assessed. Here, we describe in detail the performance of 13 signing deaf children aged 5-14 years on normed tests of British Sign Language (BSL) sentence comprehension, repetition of nonsense signs, expressive grammar and narrative skills, alongside tests of non-verbal intelligence and fine motor control. Results show these children to have a significant language delay compared to their peers matched for age and language experience. This impaired development cannot be explained by poor exposure to BSL, or by lower general cognitive, social, or motor abilities. As is the case for SLI in spoken languages, we find heterogeneity within the group in terms of which aspects of language are affected and the severity of the impairment. We discuss the implications of the existence of language impairments in a sign language for theories of SLI and clinical practice.

Gesture production and comprehension in children with specific language impairment

Children with specific language impairment (SLI) have difficulties with spoken language. However, some recent research suggests that these impairments reflect underlying cognitive limitations. Studying gesture may inform us clinically and theoretically about the nature of the association between language and cognition. A total of 20 children with SLI and 19 typically developing (TD) peers were assessed on a novel measure of gesture production. Children were also assessed for sentence comprehension errors in a speech-gesture integration task. Children with SLI performed equally to peers on gesture production but performed less well when comprehending integrated speech and gesture. Error patterns revealed a significant group interaction: children with SLI made more gesture-based errors, whilst TD children made semantically based ones. Children with SLI accessed and produced lexically encoded gestures despite having impaired spoken vocabulary and this group also showed stronger associations between gesture and language than TD children. When SLI comprehension breaks down, gesture may be relied on over speech, whilst TD children have a preference for spoken cues. The findings suggest that for children with SLI, gesture scaffolds are still more related to language development than for TD peers who have out-grown earlier reliance on gestures. Future clinical implications may include standardized assessment of symbolic gesture and classroom based gesture support for clinical groups.

Brainstem correlates of temporal auditory processing in children with specific language impairment

Deficits in identification and discrimination of sounds with short inter-stimulus intervals or short formant transitions in children with specific language impairment (SLI) have been taken to reflect an underlying temporal auditory processing deficit. Using the sustained frequency following response (FFR) and the onset auditory brainstem responses (ABR) we evaluated if children with SLI show abnormalities at the brainstem level consistent with a temporal processing deficit. To this end, the neural encoding of tonal sweeps, as reflected in the FFR, for different rates of frequency change, and the effects of reducing inter-stimulus interval on the ABR components were evaluated in 10 4-11-year-old SLI children and their age-matched controls. Results for the SLI group showed degraded FFR phase-locked neural activity that failed to faithfully track the frequency change presented in the tonal sweeps, particularly at the faster sweep rates. SLI children also showed longer latencies for waves III and V of the ABR and a greater prolongation of wave III at high stimulus rates (>30/sec), suggesting greater susceptibility to neural adaptation. These results taken together appear to suggest a disruption in the temporal pattern of phase-locked neural activity necessary to encode rapid frequency change and an increased susceptibility to desynchronizing factors related to faster rates of stimulus presentation in children with SLI.

Speech-language characteristics of children with neurofibromatosis type 1

Delays in speech and articulation development have been found in school-aged children and adolescents with neurofibromatosis type 1 (NF1). This report examines speech and language skills of preschool children with NF1. Nineteen 3- to 5-year-old children diagnosed with NF1 were assessed using measures of articulation (GFTA-2), and receptive and expressive language (CELF-P2). Significant differences were observed between mean scores obtained by the group of children with NF1 compared to the validated controls from the speech and language instruments (P < or = 0.009). Sixty-eight percent of the children exhibited delays in speech and/or language. Thirty-two percent demonstrated delays in articulation, 37% percent demonstrated delays in receptive language, and 37% exhibited delays in expressive language. Sixteen percent of the children exhibited a voice disorder and 42% were judged to have a resonance problem. No significant differences were observed on any of the measures of speech and language for children with non-familial versus familial NF1. Results of this study support the need for early assessment of speech and language problems for children diagnosed with NF1 and implementation of appropriate timely intervention as needed.