Development of verb inflections among Bangla-speaking children with language disorder.

BACKGROUND: Children with language disorder across languages have problems with verb morphology. The nature of these problems varies according to the typology of the language. The language analyzed in this paper is the Standard Bangla spoken in Dhaka, Bangladesh, by more than 200 million people. It is an underexplored language with agglutinative features in its verb inflections. Some information on the acquisition of the language by typically developing children is available, but to date we have no information on the nature of ALD. As in many places in the developing world, the circumstances for research into language disorder are challenging, as there is no well-ordered infrastructure for the identification of these children and approaches to intervention are not evidence based. This study represents the first attempt to characterize the nature of morphosyntactic limitations in standard Bangla-speaking children with language disorder. AIMS: To describe the performance of a group of children with language disorder on elicitation procedures for three Bangla verb inflections of increasing structural complexity-present simple, present progressive and past progressive-and to compare their abilities on these forms with those of a group of typically developing Bangla-speaking children. METHODS & PROCEDURES: Nine children with language disorder (mean age = 88.11 months) were recruited from a special school in Dhaka. Eight of the children also had a differentiating or co-occurring condition. They responded to three tasks: a semi-structured conversation to elicit present simple, and two picture-based tasks to elicit present progressive and past progressive. Their performance was compared with data available from a large group of younger typically developing children. OUTCOMES AND RESULTS: Group data indicated a comparable trajectory of performance by the children with language disorder with the typically developing children (present simple > present progressive > past progressive), but with significantly lower mean scores. Standard deviations suggested considerable individual variation and individual profiles were constructed for each child, revealing varying patterns of ability, some of which did not accord with the typical developmental trajectory and/or substitution patterns. CONCLUSIONS & IMPLICATIONS: This study identified verb morphology deficits in Bangla-speaking children with language disorder who had asociated conditions. Variation in performance among the children suggests that individual profiles will be most effective in guiding intervention.

Visuospatial and Verbal Short-Term Memory Correlates of Vocabulary Ability in Preschool Children.

Background: Recent studies indicate that school-age children's patterns of performance on measures of verbal and visuospatial short-term memory (STM) and working memory (WM) differ across types of neurodevelopmental disorders. Because these disorders are often characterized by early language delay, administering STM and WM tests to toddlers could improve prediction of neurodevelopmental outcomes. Toddler-appropriate verbal, but not visuospatial, STM and WM tasks are available. A toddler-appropriate visuospatial STM test is introduced. Method: Tests of verbal STM, visuospatial STM, expressive vocabulary, and receptive vocabulary were administered to 92 English-speaking children aged 2-5 years. Results: Mean test scores did not differ for boys and girls. Visuospatial and verbal STM scores were not significantly correlated when age was partialed out. Age, visuospatial STM scores, and verbal STM scores accounted for unique variance in expressive (51%, 3%, and 4%, respectively) and receptive vocabulary scores (53%, 5%, and 2%, respectively) in multiple regression analyses. Conclusion: Replication studies, a fuller test battery comprising visuospatial and verbal STM and WM tests, and a general intelligence test are required before exploring the usefulness of these STM tests for predicting longitudinal outcomes. The lack of an association between the STM tests suggests that the instruments have face validity and test independent STM skills.

Interrelationships Between Working Memory, Processing Speed, and Language Development in the Age Range 2-4 years.

Purpose: This study explored associations between working memory and language in children aged 2-4 years. Method: Seventy-seven children aged 24-30 months were assessed on tests measuring language, visual cognition, verbal working memory (VWM), phonological short-term memory (PSTM), and processing speed. A standardized test of receptive and expressive language was used as the outcomes measure 18 months later. Results: There were moderate-to-strong longitudinal bivariate relationships between the 3 processing measures and language outcomes. Early VWM showed the strongest bivariate relationship with both later expressive (r = .71) and receptive language (r = .72). In a hierarchical multiple regression analysis, adding early VWM, PSTM, and processing speed improved prediction of receptive and expressive language outcomes (12%-13% additional variance) compared with models consisting only of early receptive or expressive language, parent education, and age. Conclusions: Unique associations in hierarchical regression analyses were demonstrated between VWM at age two years and receptive and expressive language skills at age four, and between early processing speed and later receptive language. However, early PSTM did not predict unique variance in language outcomes, as it shared variance with other measures.

Exploring Expressive Vocabulary Variability in Two-Year-Olds: The Role of Working Memory.

PURPOSE: This study explored whether measures of working memory ability contribute to the wide variation in 2-year-olds' expressive vocabulary skills. METHOD: Seventy-nine children (aged 24-30 months) were assessed by using standardized tests of vocabulary and visual cognition, a processing speed measure, and behavioral measures of verbal working memory and phonological short-term memory. RESULTS: Strong correlations were observed between phonological short-term memory, verbal working memory, and expressive vocabulary. Speed of spoken word recognition showed a moderate significant correlation with expressive vocabulary. In a multivariate regression model for expressive vocabulary, the most powerful predictor was a measure of phonological short-term memory (accounting for 66% unique variance), followed by verbal working memory (6%), sex (2%), and age (1%). Processing speed did not add significant unique variance. CONCLUSIONS: These findings confirm previous research positing a strong role for phonological short-term memory in early expressive vocabulary acquisition. They also extend previous research in two ways. First, a unique association between verbal working memory and expressive vocabulary in 2-year-olds was observed. Second, processing speed was not a unique predictor of variance in expressive vocabulary when included alongside measures of working memory.

Study of child language development and disorders in Iran: A systematic review of the literature.

Child language development and disorder in Iran has been the focus for research by different professions, the most prominent ones among them being psychologists and speech therapists. Epidemiological studies indicate that between 8% and 12% of children show noticeable signs of language impairment in the preschool years; however, research on child language in Iran is not extensive compared to studies in English speaking countries, which are currently the basis of clinical decision-making in Iran. Consequently, there is no information about the prevalence of child language disorders in Iranian population. This review summarizes Iranian studies on child language development and disorder in the preschool years and aims to systematically find the most studied topics in the field of normal development, the assessment and diagnosis of language impairments as well as exploring the current gaps within the body of literature. Three main Iranian academic websites of indexed articles along with four other nonIranian databases were scrutinized for all relevant articles according to the inclusion criteria: Iranian studies within the field of Persian language development and disorders in preschool children published up to December 2013. They are classified according to the hierarchy of evidence and weighed against the criteria of critical appraisal of study types. As this is a type of nonintervention systematic review, the preferred reporting items for systematic reviews and meta-analyses is modified to be more compatible to the designs of eligible studies, including descriptive studies, test-developing and/or diagnostic studies. Several limitations made the process of searching and retrieving problematic; e.g., lack of unified keywords and incompatibility of Persian typing structure embedded in Iranian search engines. Overall, eligible studies met the criteria up to the third level of the hierarchy of evidence that shows the necessity of conducting studies with higher levels of design and quality.

Diagnostic accuracy of language sample measures with Persian-speaking preschool children.

This study examined the diagnostic accuracy of selected language sample measures (LSMs) with Persian-speaking children. A pre-accuracy study followed by phase I and II studies are reported. Twenty-four Persian-speaking children, aged 42 to 54 months, with primary language impairment (PLI) were compared to 27 age-matched children without PLI on a set of measures derived from play-based, conversational language samples. Results showed that correlations between age and LSMs were not statistically significant in either group of children. However, a majority of LSMs differentiated children with and without PLI at the group level (phase I), while three of the measures exhibited good diagnostic accuracy at the level of the individual (phase II). We conclude that general LSMs are promising for distinguishing between children with and without PLI. Persian-specific measures are mainly helpful in identifying children without language impairment while their ability to identify children with PLI is poor.

Early language delay and specific language impairment.

Early language delay (ELD) is a warning sign that may presage the presence of a later language impairment (LI). In order to allow more targeted identification and earlier intervention for LI, better diagnostic measures for toddlers are needed. Development of accurate predictive/diagnostic models requires consideration of a set of complex interrelated questions around definition, causality, and theories of LIs. A multifactorial model of language development and LI is essential to increase the accuracy of prediction. This article examines what is known about LI in the preschool years and language delay in toddlers, and examines these in relation to the Procedural Deficit Hypothesis (Ullman and Pierpont, [2005] Cortex 41:399-433] and the Statistical Learning Account (Stokes et al., [2012a] J Speech Lang Hear Res; Stokes et al., [2012b] J Child Lang 39:105-129) to suggest a new framework for characterizing ELD to better assist prediction of later LI.

Differentiating Cantonese-speaking preschool children with and without SLI using MLU and lexical diversity (D).

PURPOSE: In this study, the authors examined the diagnostic accuracy of a composite clinical assessment measure based on mean length of utterance (MLU), lexical diversity (D), and age (Klee, Stokes, Wong, Fletcher, & Gavin, 2004) in a second, independent sample of 4-year-old Cantonese-speaking children with and without specific language impairment (SLI). METHOD: The composite measure was calculated from play-based, conversational language samples of 15 children with SLI and 14 children without SLI. Scores were dichotomized and compared to diagnostic outcomes using a reference standard based on clinical judgment supported by test scores. RESULTS: Eleven of 15 children with SLI and 8 of 14 children with typical language skills were correctly classified by the dichotomized composite measure. The measure's sensitivity in this second sample was 73.3% (95% confidence interval [CI] 48%-89%); specificity was 57.1% (95% CI 33%-79%); positive likelihood ratio was 1.71 (95% CI 0.87-3.37); and negative likelihood ratio was 0.47 (95% CI 0.18-1.21). CONCLUSIONS: The diagnostic accuracy of the composite measure was substantially lower than in the original study, suggesting that it is unlikely to be informative for clinical use in its present form. The value of replication studies is discussed.

An exploratory trial of the effectiveness of an enhanced consultative approach to delivering speech and language intervention in schools.

BACKGROUND: Increased demand for access to specialist services for providing support to children with speech, language and communication needs prompted a local service review of how best to allocate limited resources. This study arose as a consequence of a wish to evaluate the effectiveness of an enhanced consultative approach to delivering speech and language intervention in local schools. AIMS: The purpose was to evaluate an intensive speech and language intervention for children in mainstream schools delivered by specialist teaching assistants. METHODS & PROCEDURES: A within-subjects, quasi-experimental exploratory trial was conducted, with each child serving as his or her own control with respect to the primary outcome measure. Thirty-five children between the ages of 4;2 and 6;10 (years; months) received speech and/or language intervention for an average of four 1-hour sessions per week over 10 weeks. The primary outcome measure consisted of change between pre- and post-intervention scores on probe tasks of treated and untreated behaviours summed across the group of children, and maintenance probes of treated behaviours. Secondary outcome measures included standardized tests (Clinical Evaluation of Language Fundamentals - Preschool(UK) (CELF-P(UK)); Diagnostic Evaluation of Articulation and Phonology (DEAP)) and questionnaires completed by parents/carers and school staff before and after the intervention period. OUTCOME & RESULTS: The primary outcome measure showed improvement over the intervention period, with target behaviours showing a significantly larger increase than control behaviours. The gains made on the target behaviours as a result of intervention were sustained when reassessed 3-12 months later. These findings were replicated on a second set of targets and controls. Significant gains were also observed on CELF-Preschool(UK) receptive and expressive language standard scores from pre- to post-intervention. However, DEAP standard scores of speech ability did not increase over the intervention period, although improvements in raw scores were observed. Questionnaires completed before and after intervention showed some significant differences relating to how much the child's speech and language difficulties affected him/her at home and at school. CONCLUSIONS & IMPLICATIONS: This exploratory study demonstrates the benefit of an intensive therapy delivered by specialist teaching assistants for remediating speech and language difficulties experienced by young children in mainstream schools. The service delivery model was perceived by professionals as offering an inclusive and effective practice and provides empirical support for using both direct and indirect intervention in the school setting.

The diagnostic accuracy of a new test of early nonword repetition for differentiating late talking and typically developing children.

PURPOSE: To assess the diagnostic accuracy of a new Test of Early Nonword Repetition (TENR) for 2-year-old children. METHOD: 232 British-English-speaking children aged 27 (+/-3) months were assessed on 3 standardized tests (receptive and expressive vocabulary and visual processing) and a novel nonword repetition (NWR) test. Parents completed a British adaptation of the MacArthur-Bates Communicative Development Inventory: Words and Sentences (CDI:WS-UK; Klee & Harrison, 2001). The diagnostic accuracy of two versions (1-3 syllables and 1-4 syllables) of a new NWR test was examined. Standard diagnostic accuracy measures of sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratios were generated. RESULTS: 177 children (80%) completed the 1-3 syllable task, and 96 children (73%) completed the 1-4 syllable task. The 1-3 syllable version produced a positive likelihood ratio (LR+) of 7.8 (confidence interval [CI] = 4.5-13.6) and a negative likelihood ratio (LR-) of .28 (CI = .12-.65). The 1-4 syllable version of the NWR test produced a LR+ of 14.88 (CI = 6.1-36.2) and a LR- of .13 (CI = .02-.83). CONCLUSION: The TENR could be useful for identifying 2-year-old children at risk of language impairment.

Factors that influence vocabulary development in two-year-old children.

BACKGROUND: This research explored the relative impact of demographic, cognitive, behavioural, and psycholinguistic factors on vocabulary development in two-year-old children. METHODS: Two hundred and thirty-two children (24-30 months) were tested on expressive and receptive vocabulary, cognitive development, word learning and working memory skills. Parents completed a British adaptation (Klee & Harrison, 2001) of the MacArthur-Bates Communicative Development Inventory (CDI; Fenson et al., 1993), a demographic questionnaire and a questionnaire regarding the child's social-emotional behaviour. RESULTS: Several demographic, child and processing variables were significantly correlated with CDI (vocabulary) scores, but the only significant unique predictors of CDI scores were nonword repetition (NWR; R(2) change = .36), sex (R(2) change = .05) and age (R(2) change = .04). Scores were only included when a child completed the entire NWR test (77% of toddlers). CONCLUSIONS: The NWR task used in this experiment maximised participation in this group of toddlers, and was a strong predictor of vocabulary ability. Longitudinal research is warranted to explore the independent and reciprocal growth in working memory and language skills in children.

Lexical mixing in the early productive vocabularies of Maltese children: implications for intervention.

Since norms for vocabulary acquisition in Maltese children do not yet exist, documentation of productive vocabulary acquisition may contribute to establishing a baseline of lexical development. Clinical implications may thus be derived. The current study is a small-scale investigation of the proportions of Maltese and English lexemes in the vocabularies of ten normally-developing Maltese children aged between 12 and 30 months. The participants were primarily exposed to Maltese within their immediate environments, while receiving indirect exposure to English. Outcomes of parental report and language sampling were analysed for evidence of a bilingual dimension in these children's productive vocabularies. Translation equivalents were reported on by parents, but negligible evidence of equivalents emerged in conversational language use. In contrast, lexical borrowings were both reported and sampled. A substantial proportion of English lexemes were reported by the parents in the absence of Maltese equivalents.

A phonemic implicational feature hierarchy of phonological contrasts for English-speaking children.

Contrastive feature hierarchies have been developed and used for some time in depicting typical phonological development and in guiding therapy decisions. Previous descriptions of feature use have been based on independent analyses and usually phonetic inventories. However, recent trends in phonology include a relational analysis of phonemic inventories (D. Ingram & K. D. Ingram, 2001). The current investigation was a relational analysis of the phonemic inventories of 40 typically developing 2-year-old American-English-speaking children. Consonant inventories were derived from spontaneous speech samples using the Logical International Phonetics Programs computer software (D. K. Oller & R. E. Delgado, 1999). Cluster analysis was used to determine the grouping of contrastive features. Four levels emerged. Level I included [consonant], [sonorant], and [coronal], Level II included [voice], Level III included [anterior], [continuant], and [nasal], and Level IV included [lateral] and [strident]. Results suggested that the resulting 4-level phonemic feature hierarchy might be used to classify the phonological systems of children with phonological disorders.

Utterance length and lexical diversity in Cantonese-speaking children with and without specific language impairment.

Two studies of children's conversational language abilities are reported. In the first, mean length of utterance (MLU) and lexical diversity (D) were examined in a group of typically developing Cantonese-speaking children in Hong Kong. Regression analyses indicated a significant linear relationship between MLU and age (R = .44) and a significant curvilinear relationship between D and age (R = .73) in children age 27-68 months. MLU and D were moderately correlated with each other (r = .23); however, the two measures showed no statistical relationship when the effect of age was partialled out. In a second study, the utterances of Chinese children with specific language impairment (SLI) were found to be significantly shorter and less lexically diverse than typically developing children matched for age but similar to children matched for comprehension level. Discriminant analyses revealed that the combination of age, MLU, and D could be used to accurately differentiate children with SLI from both age-matched and language-matched children. Based on these findings, we hypothesize that these measures can be used jointly as a marker of SLI in Cantonese-speaking children.

Phonological profiles of 2-year-olds with delayed language development: predicting clinical outcomes at age 3.

Twenty-eight 2-year-olds were screened for language development using the Language Development Survey (LDS; L. Rescorla, 1989) and underwent a clinical evaluation within a month following LDS administration. Six measures of phonological development were derived from 20-min language samples of parent-child play interactions, including number of different consonants, number of different consonants in the initial and final positions, number of different consonant clusters in the initial and final position, and percentage of closed syllables shapes. Comparisons were made among 3 groups: (a) those who screened positive on the LDS (LDS+) who were within normal limits on follow-up, (b) those who were identified as language delayed (LD), and (c) children who were language normal (LN). Results revealed that children who were LDS+ and LD had comparable phonetic profiles. The LD group had significantly lower scores on all phonetic measures tested, as compared to the LN group. Clinical recommendations were available on a subset of 13 children who were reassessed at age 3. Children who received "monitor" or "treatment" recommendations at age 3 had significantly lower z scores on measures of phonetic development recorded at 2 years of age than toddlers who received a recommendation of "no concerns" at 3 years. Our preliminary findings indicated that the more delayed the 2-year-old child was in phonological development, the more at risk the child was for continuing delays at age 3.