Vocabulary Acquisition and Usage for Late Talkers Treatment: Effect on Expressive Vocabulary and Phonology.

Purpose This study examined the effect of Vocabulary Acquisition and Usage for Late Talkers (VAULT) treatment on toddlers' expressive vocabulary and phonology. Parent acceptability of VAULT treatment was also considered. Method We used a nonconcurrent multiple baseline single case experimental design with three late talking toddlers aged 21-25 months. The treatment was delivered twice weekly in 30-min sessions for 8 weeks by a rotating team of four speech-language pathologists. Toddlers heard three of their 10 strategically selected target words a minimum of 64 times in play activities each session. Expressive vocabulary and phonology was assessed pre-post, with parent interviews conducted posttreatment. Results All toddlers increased production of target words and expressive vocabulary. Ambient expressive vocabulary size increased by an average of 16 words per week (range of 73-169 words learned over the treatment period). On a 20-item, single-word speech assessment, the toddlers' phonetic inventories increased on average from three to seven consonants, and five to eight vowels. Two toddlers used protowords pretreatment, which were replaced by recognizable attempts at words posttreatment. Parents reported the treatment was acceptable for the child and their family with future consideration of parent-based delivery of the treatment in the home. Conclusions The results of this treatment provide further evidence of a model of intervention informed by the principles of implicit learning, and the interconnectedness of phonological and lexical learning. Investigation is required to establish the efficacy and feasibility of VAULT in clinical contexts. Supplemental Material https://doi.org/10.23641/asha.14714733.

Successful Implicit Vocabulary Intervention for Three Cantonese-Speaking Toddlers: A Replicated Single-Case Design.

Purpose We report on a replicated single-case design study that measured the feasibility of an expressive vocabulary intervention for three Cantonese-speaking toddlers with small expressive lexicons relative to their age. The aim was to assess the cross-cultural and cross-linguistic feasibility of an intervention method developed for English-speaking children. Method A nonconcurrent multiple-baseline design was used with four baseline data points and 16 intervention sessions per participant. The intervention design incorporated implicit learning principles, high treatment dosage, and control of the phonological neighborhood density of the stimuli. The children (24-39 months) attended 7-9 weeks of twice weekly input-based treatment in which no explicit verbal production was required from the child. Each target word was provided as input a minimum of 64 times in at least two intervention sessions. Treatment feasibility was measured by comparison of how many of the target and control words the child produced across the intervention period, and parent-reported expressive vocabulary checklists were completed for comparison of pre- and postintervention child spoken vocabulary size. An omnibus effect size for the treatment effect of the number of target and control words produced across time was calculated using Kendall's Tau. Results There was a significant treatment effect for target words learned in intervention relative to baselines, and all children produced significantly more target than control words across the intervention period. The effect of phonological neighborhood density on expressive word production could not be evaluated because two of the three children learned all target words. Conclusion The results provide cross-cultural evidence of the feasibility of a model of intervention that incorporated a high-dosage, cross-situational statistical learning paradigm to teach spoken word production to children with small expressive lexicons.

Phonology, Semantics, and the Comprehension-Expression Gap in Emerging Lexicons.

Purpose Children come to understand many words by the end of their 1st year of life, and yet, generally by 12 months, only a few words are said. In this study, we investigated which linguistic factors contribute to this comprehension-expression gap the most. Specifically, we asked the following: Are phonological neighborhood density, semantic neighborhood density, and word frequency (WF) significant predictors of the probability that words known (understood) by children would appear in their spoken lexicons? Method Monosyllabic words in the active (understood and said) and passive (understood, not said) lexicons of 201 toddlers were extracted from the Dutch Communicative Development Inventory (Zink & Lejaegere, 2002) parent-completed forms. A generalized linear mixed-effects model was applied to the data. Results Phonological neighborhood density and WF were independently and significantly associated with whether or not a known word would be in children's spoken lexicons, but semantic neighborhood density was not. There were individual differences in the impact of WF on the probability that known words would be said. Conclusion The novel findings reported here have 2 major implications. First, they indicate that the comprehension-expression gap exists partly because the phonological distributional properties of words determine how readily words can be phonologically encoded for word production. Second, there are likely subtle and complex individual differences in how and when the statistical properties of the ambient language impact on children's emerging lexicons that might best be explored via longitudinal sampling of word knowledge and use.

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.

Influence of consonant frequency on Icelandic-speaking children's speech acquisition.

PURPOSE: A developmental hierarchy of phonetic feature complexity has been proposed, suggesting that later emerging sounds have greater articulatory complexity than those learned earlier. The aim of this research was to explore this hierarchy in a relatively unexplored language, Icelandic. METHOD: Twenty-eight typically-developing Icelandic-speaking children were tested at 2;4 and 3;4 years. Word-initial and word-medial phonemic inventories and a phonemic implicational hierarchy are described. RESULT: The frequency of occurrence of Icelandic consonants in the speech of 2;4 and 3;4 year old children was, from most to least frequent, n, s, t, p, r, m, l, k, f, ʋ, j, ɵ, h, kÊ°, c, [Formula: see text], É°, pÊ°, tÊ°, cÊ°, ç, [Formula: see text], [Formula: see text], [Formula: see text]. CONCLUSION: Consonant frequency was a strong predictor of consonant accuracy at 2;4 months (r(23) = -0.75), but the effect was weaker at 3;4 months (r(23) = -0.51). Acquisition of /c/, /[Formula: see text]/ and /l/ occurred earlier, relative to English, Swedish, Dutch and German. A frequency-bound practice effect on emerging consonants is proposed to account for the early emergence of /c/, /[Formula: see text]/ and /l/ in Icelandic.

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.

Literacy skills of Australian Indigenous school children with and without otitis media and hearing loss.

This study examined the relationship between reading, spelling, and the presence of otitis media (OM) and co-occurring hearing loss (HL) in metropolitan Indigenous Australian children, and compared their reading and spelling outcomes with those of their non-Indigenous peers. OM and HL may hinder language development and phonological awareness skills, but there is little empirical evidence to link OM/HL and literacy in this population. Eighty-six Indigenous and non-Indigenous children attending pre-primary, year one and year two at primary schools in the Perth metropolitan area participated in the study. The ear health of the participants was screened by Telethon Speech and Hearing Centre EarBus in 2011/2012. Participants' reading and spelling skills were tested with culturally modified sub-tests of the Queensland University Inventory of Literacy. Of the 46 Indigenous children, 18 presented with at least one episode of OM and one episode of HL. Results indicated that Indigenous participants had significantly poorer non-word and real word reading and spelling skills than their non-Indigenous peers. There was no significant difference between the groups of Indigenous participants with OM and HL and those with normal ear health on either measure. This research provides evidence to suggest that Indigenous children have ongoing literacy development difficulties and discusses the possibility of OM as one of many impacting factors.

The impact of phonological neighborhood density on typical and atypical emerging lexicons*.

According to the Extended Statistical Learning account (ExSL; Stokes, Kern & dos Santos, 2012) late talkers (LTs) continue to use neighborhood density (ND) as a cue for word learning when their peers no longer use a density learning mechanism. In the current article, LTs expressive (active) lexicon ND values differed from those of their age-matched, but not language-matched, TD peers, a finding that provided support for the ExSL account. Stokes (2010) claimed that LTs had difficulty abstracting sparse words, but not dense, from the ambient language. If true, then LTs' receptive (passive), as well as active lexicons should be comprised of words of high ND. However, in the current research only active lexicons were of high ND. LTs' expressive lexicons may be small not because of an abstraction deficit, but because they are unable to develop sufficiently strong phonological representations to support word production.

Community-based early intervention for language delay: a preliminary investigation.

BACKGROUND: A trial parent-focused early intervention (PFEI) programme for children with delayed language development is reported in which current research evidence was translated and applied within the constraints of available of clinical resources. The programme, based at a primary school, was run by a speech-language pathologist with speech-language pathology students. AIM: To investigate the changes in child language development and parent and child interactions following attendance at the PFEI. METHODS & PROCEDURES: Eighteen parents and their children attended six, weekly group sessions in which parents were provided with strategies to maximize language learning in everyday contexts. Pre- and post-programme assessments of vocabulary size and measures of parent-child interaction were collected. OUTCOME & RESULTS: Parents and children significantly increased their communicative interactions from pre- to post-treatment. Children's expressive vocabulary size and language skills increased significantly. Large-effect sizes were observed. CONCLUSIONS & IMPLICATIONS: The positive outcomes of the intervention programme contribute to the evidence base of intervention strategies and forms of service delivery for children at risk of language delay.

Statistical learning in emerging lexicons: the case of Danish.

PURPOSE: This research explored the impact of neighborhood density (ND), word frequency (WF), and word length (WL) on the vocabulary size of Danish-speaking children. Given the particular phonological properties of Danish, the impact was expected to differ from that reported in studies on English and French. METHOD: The monosyllabic words in the expressive lexicons of 894 Danish-speaking 2-year-old children were coded for ND, WF, and WL. Lexicons were extracted from parent checklists of the words spoken by their children. RESULTS: Regression revealed that ND, WF, WL, and age together predicted 47% of the variance in vocabulary size, with ND, WF, WL, and age uniquely accounting for 39%, 3.2%, 2.2%, and 2.8% of that variance, respectively. Children with small vocabularies had learned words that were denser and more frequent in the ambient language, and those words were shorter than the words of children with larger vocabularies. CONCLUSION: The 2 main findings were unexpected. The impact of ND for Danish-speaking children was not expected given the phonological properties of the language. The WF results differed from those of English because of the distribution of word classes on the language-relevant parent checklists. The strong role for ND in emerging languages found in other languages was replicated for Danish.

Extended Statistical Learning as an account for slow vocabulary growth.

Stokes (2010) compared the lexicons of English-speaking late talkers (LT) with those of their typically developing (TD) peers on neighborhood density (ND) and word frequency (WF) characteristics and suggested that LTs employed learning strategies that differed from those of their TD peers. This research sought to explore the cross-linguistic validity of this conclusion. The lexicons (production, not recognition) of 208 French-speaking two-year-old children were coded for ND and WF. Regression revealed that ND and WF together predicted 62% of the variance in vocabulary size, with ND and WF uniquely accounting for 53% and 9% of that variance respectively. Epiphenomenal findings were ruled out by comparison of simulated data sets with the actual data. A generalized Mann-Whitney test showed that children with small vocabularies had significantly higher ND values and significantly lower WF values than children with large vocabularies. An EXTENDED STATISTICAL LEARNING theory is proposed to account for the findings.

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.

Narrative assessment for Cantonese-speaking children.

BACKGROUND: This study examined the narrative skills of Cantonese-speaking school-age children to fill a need for a normative language test for school-age children. PURPOSE: To provide a benchmark of the narrative skills of Cantonese-speaking children; to identify which of the microstructure components was the best predictor of age; and to determine the diagnostic accuracy of the test components. METHOD AND PROCEDURE: Data were collected from 1,120 Cantonese-speaking children between the ages of 4;10 (years;months) and 12;01, using a story-retell of a 24-frame picture series. Four narrative components (syntactic complexity, semantic score, referencing, and connective use) were measured. OUTCOMES AND RESULTS: Each measure reflected significant age-related differences in narrative ability. Regression analyses revealed that vocabulary and syntactic complexity were the best predictors of grade. All measures showed high sensitivity (86%-94%) but relatively low specificity (60%-90%) and modest likelihood ratio (LR) values: LR+ (2.15-9.42) and LR- (0.07-0.34). CONCLUSION AND IMPLICATIONS: Narrative assessment can be standardized to be a reliable and valid instrument to assist in the identification of children with language impairment. Syntactic complexity is not only a strong predictor of grade but was also particularly vulnerable in Cantonese-speaking children with specific language impairment. Further diagnostic research using narrative analysis is warranted.

Neighborhood density and word frequency predict vocabulary size in toddlers.

PURPOSE: To document the lexical characteristics of neighborhood density (ND) and word frequency (WF) in the lexicons of a large sample of English-speaking toddlers. METHOD: Parents of 222 British-English-speaking children aged 27(+/-3) months completed a British adaptation of the MacArthur-Bates Communicative Development Inventory: Words and Sentences (MCDI; Klee & Harrison, 2001). Child words were coded for ND and WF, and the relationships among vocabulary, ND, and WF were examined. A cut-point of -1 SD below the mean on the MCDI classified children into one of two groups: low or high vocabulary size. Group differences on ND and WF were examined using nonparametric statistics. RESULTS: In a hierarchical regression, ND and WF accounted for 47% and 14% of unique variance in MCDI scores, respectively. Low-vocabulary children scored significantly higher on ND and significantly lower on WF than did high-vocabulary children, but there was more variability in ND and WF for children at the lowest points of the vocabulary continuum. CONCLUSION: Children at the lowest points of a continuum of vocabulary size may be extracting statistical properties of the input language in a manner quite different from their more able age peers.

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.

Early oral language markers of poor reading performance in Hong Kong Chinese children.

This study investigated the extent to which language skills at ages 2 to 4 years could discriminate Hong Kong Chinese poor from adequate readers at age 7. Selected were 41 poor readers (age M = 87.6 months) and 41 adequate readers (age M = 88.3 months). The two groups were matched on age, parents' education levels, and nonverbal intelligence. The following language tasks were tested at different ages: vocabulary checklist and Cantonese articulation test at age 2; nonword repetition, Cantonese articulation, and receptive grammar at age 3; and nonword repetition, receptive grammar, sentence imitation, and story comprehension at age 4. Significant differences between the poor and adequate readers were found in the age 2 vocabulary knowledge, age 3 Cantonese articulation, and age 4 receptive grammar skill, sentence imitation, and story comprehension. Among these measures, sentence imitation showed the greatest power in discriminating poor and adequate readers.

The use of facilitative vowel contexts in the treatment of post-alveolar fronting: a case study.

BACKGROUND: School-aged children with persisting speech sound disorders (SSDs) may show little improvement in speech accuracy following phonological or articulation therapy. AIMS: To determine the effects of establishing consonant production in facilitative vowel contexts for a 7-year-old boy (CD) with persisting post-alveolar fronting. CD had received phonological awareness therapy and traditional articulation therapy as part of a community caseload. However, his post-alveolar fronting showed resistance to therapy. METHODS & PROCEDURES: CD received individual therapy for nine 45-55-min sessions. A checklist of quality indicators for single-subject research was used to explore the likelihood that a community clinic could meet quality indicators. Fifteen test words in each of target, generalization and control sets were measured at five times pre-, during and post-therapy. A trend analysis was used to measure the statistical significance of the results and to demonstrate the efficacy of therapy. OUTCOMES & RESULTS: Therapy was successful. Gains on treatment and generalization test items were rapid and significantly higher than gains on control test items. Only three of 21 single-subject research quality indicators were not met in this research. CONCLUSIONS & IMPLICATIONS: Targeting facilitative vowel contexts was successful for this 7-year-old boy with persisting post-alveolar fronting which had been resistant to other therapy techniques. Speech and language therapists are encouraged to ensure that quality indicators for single-subject interventions are built into regular practice.

Optional elements and variant structures in the productions of bei2 'to give' dative constructions in Cantonese-speaking adults and three-year-old children.

To express object transfer, Cantonese-speakers use a 'ditransitive' ([V-R-T] or [V-T-R] where V=Verb, T=Theme, R=Recipient), or a more complex prepositional/serial-verb (P/SV) construction. Clausal elements in Cantonese datives can be optional (resulting in 'full' versus 'non-full' forms) or appear in variant orders (full non-canonical and full canonical). We report on usage of dative constructions with the word bei2 'to give' in 86 parents and 53 three-year-old children during conversations. The parents used more P/SV than ditransitive bei2-datives, and vice versa for the children. Both groups showed a similar usage pattern of optional elements and variant structures in their ditransitive and P/SV bei2-datives. The roles of multiple construction types, optional elements and variant structures in children's learning of bei2-dative constructions are described.