Phonological working memory and central executive function differ in children with typical development and dyslexia.

The primary purpose of this study was to compare the working memory performance of monolingual English-speaking second- grade children with dyslexia (N = 82) to second-grade children with typical development (N = 167). Prior to making group comparisons, it is important to demonstrate invariance between working memory models in both groups or between-group comparisons would not be valid. Thus, we completed invariance testing using a model of working memory that had been validated for children with typical development (Gray et al., 2017) to see if it was valid for children with dyslexia. We tested three types of invariance: configural (does the model test the same constructs?), metric (are the factor loadings equivalent?), and scalar (are the item intercepts the same?). Group comparisons favoured the children with typical development across all three working memory factors. However, differences in the Focus-of-Attention/Visuospatial factor could be explained by group differences in non-verbal intelligence and language skills. In contrast, differences in the Phonological and Central Executive working memory factors remained, even after accounting for non-verbal intelligence and language. Results highlight the need for researchers and educators to attend not only to the phonological aspects of working memory in children with dyslexia, but also to central executive function.

Phonological Working Memory and Sentence Production in School-Age Children with Typical Language, Dyslexia, and Comorbid Dyslexia and Developmental Language Disorder.

PURPOSE: Little is known about the relationship between sentence production and phonological working memory in school-age children. To fill this gap, we examined how strongly these constructs correlate. We also compared diagnostic groups' working memory abilities to see if differences co-occurred with qualitative differences in their sentences. METHOD: We conducted Bayesian analyses on data from seven- to nine-year-old children (n = 165 typical language, n = 81 dyslexia-only, n = 43 comorbid dyslexia and developmental language disorder). We correlated sentence production and working memory scores and conducted t tests between groups' working memory scores and sentence length, lexical diversity, and complexity. RESULTS: Correlations were positive but weak. The dyslexic and typical groups had dissimilar working memory and comparable sentence quality. The dyslexic and comorbid groups had comparable working memory but dissimilar sentence quality. CONCLUSION: Contrary to literature-based predictions, phonological working memory and sentence production are weakly related in school-age children.

REM sleep in naps differentially relates to memory consolidation in typical preschoolers and children with Down syndrome.

Sleep is recognized as a physiological state associated with learning, with studies showing that knowledge acquisition improves with naps. Little work has examined sleep-dependent learning in people with developmental disorders, for whom sleep quality is often impaired. We examined the effect of natural, in-home naps on word learning in typical young children and children with Down syndrome (DS). Despite similar immediate memory retention, naps benefitted memory performance in typical children but hindered performance in children with DS, who retained less when tested after a nap, but were more accurate after a wake interval. These effects of napping persisted 24 h later in both groups, even after an intervening overnight period of sleep. During naps in typical children, memory retention for object-label associations correlated positively with percent of time in rapid eye movement (REM) sleep. However, in children with DS, a population with reduced REM, learning was impaired, but only after the nap. This finding shows that a nap can increase memory loss in a subpopulation, highlighting that naps are not universally beneficial. Further, in healthy preschooler's naps, processes in REM sleep may benefit learning.

Phonological Vulnerability for School-Aged Spanish-English-Speaking Bilingual Children.

This study examined accuracy on syllable-final (coda) consonants in newly-learned English-like nonwords to determine whether school-aged bilingual children may be more vulnerable to making errors on English-only codas than their monolingual, English-speaking peers, even at a stage in development when phonological accuracy in productions of familiar words is high. Bilingual Spanish-English-speaking second- graders (age 7-9) with typical development (n=40) were matched individually with monolingual peers on age, sex, and speech skills. Participants learned to name sea monsters as part of five computerized word learning tasks. Dependent t-tests revealed bilingual children were less accurate than monolingual children in producing codas unique to English; however, the groups demonstrated equivalent levels of accuracy on codas that occur in both Spanish and English. Results suggest that, even at high levels of English proficiency, bilingual Spanish-English-speaking children may demonstrate lower accuracy than their monolingual English-speaking peers on targets that pattern differently in their two languages. Differences between a bilingual's two languages can be used to reveal targets that may be more vulnerable to error, which could be a result of cross-linguistic effects or more limited practice with English phonology.

Short-term Memory in Childhood Dyslexia: Deficient Serial Order in Multiple Modalities.

In children with dyslexia, deficits in working memory have not been well-specified. We assessed second-grade children with dyslexia, with and without concomitant specific language impairment, and children with typical development. Immediate serial recall of lists of phonological (non-word), lexical (digit), spatial (location) and visual (shape) items were included. For the latter three modalities, we used not only standard span but also running span tasks, in which the list length was unpredictable to limit mnemonic strategies. Non-word repetition tests indicated a phonological memory deficit in children with dyslexia alone compared with those with typical development, but this difference vanished when these groups were matched for non-verbal intelligence and language. Theoretically important deficits in serial order memory in dyslexic children, however, persisted relative to matched typically developing children. The deficits were in recall of (1) spoken digits in both standard and running span tasks and (2) spatial locations, in running span only. Children with dyslexia with versus without language impairment, when matched on non-verbal intelligence, had comparable serial order memory, but differed in phonology. Because serial orderings of verbal and spatial elements occur in reading, the careful examination of order memory may allow a deeper understanding of dyslexia and its relation to language impairment. Copyright © 2017 John Wiley & Sons, Ltd.

Vocabulary Acquisition and Usage for Late Talkers: The Feasibility of a Caregiver-Implemented Telehealth Model.

PURPOSE: This feasibility study examined a caregiver-implemented telehealth model of the Vocabulary Acquisition and Usage for Late Talkers (VAULT) protocol. We asked whether caregivers could reach fidelity on VAULT, if the protocol was socially and ecologically valid, and if late-talking toddlers could learn new words with this model. METHOD: Five late-talking monolingual and bilingual toddlers and four caregivers participated. The caregiver-related research questions involved measurements taken at multiple time points and replication across subjects but did not follow a specific research design. The toddler-related research questions included elements of a single-case design. Caregivers completed self-paced online training modules and then provided 8 weeks of VAULT to their children with remote coaching. Fidelity data were collected during coached sessions and through rating scales. Social and ecological validity data were collected via surveys and interviews. Children's word learning was measured before, during, and after treatment via production of targets and controls and via standardized vocabulary inventories. RESULTS: Caregivers demonstrated high fidelity to VAULT throughout treatment. They reported being comfortable with many aspects of VAULT. Feedback was mixed regarding the time required. Many reported their child was talking more as a result of the program. Visual analysis revealed that toddlers learned more target than control words, which was corroborated by Tau-U and d effect size analyses. CONCLUSION: A caregiver-implemented telehealth model of VAULT was feasible, was socially and ecologically valid, and benefited toddlers, making this a worthwhile model for future studies to examine. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21753872.

Harnessing automatic speech recognition to realise Sustainable Development Goals 3, 9, and 17 through interdisciplinary partnerships for children with communication disability.

PURPOSE: To showcase how applications of automatic speech recognition (ASR) technology could help solve challenges in speech-language pathology practice with children with communication disability, and contribute to the realisation of the Sustainable Development Goals (SDGs). RESULT: ASR technologies have been developed to address the need for equitable, efficient, and accurate assessment and diagnosis of communication disability in children by automating the transcription and analysis of speech and language samples and supporting dual-language assessment of bilingual children. ASR tools can automate the measurement of and help optimise intervention fidelity. ASR tools can also be used by children to engage in independent speech production practice without relying on feedback from speech-language pathologists (SLPs), thus bridging the long-standing gap between recommended and received intervention intensity. These innovative technologies and tools have been generated from interdisciplinary partnerships between SLPs, engineers, data scientists, and linguists. CONCLUSION: To advance equitable, efficient, and effective speech-language pathology services for children with communication disability, SLPs would benefit from integrating ASR solutions into their clinical practice. Ongoing interdisciplinary research is needed to further advance ASR technologies to optimise children's outcomes. This commentary paper focusses on industry, innovation and infrastructure (SDG 9) and partnerships for the goals (SDG 17). It also addresses SDG 1, SDG 3, SDG 4, SDG 8, SDG 10, SDG 11, and SDG 16.

Using principles of learning to inform language therapy design for children with specific language impairment.

BACKGROUND: Language treatment for children with specific language impairment (SLI) often takes months to achieve moderate results. Interventions often do not incorporate the principles that are known to affect learning in unimpaired learners. AIMS: To outline some key findings about learning in typical populations and to suggest a model of how they might be applied to language treatment design as a catalyst for further research and discussion. METHODS & PROCEDURES: Three main principles of implicit learning are reviewed: variability, complexity and sleep-dependent consolidation. After explaining these principles, evidence is provided as to how they influence learning tasks in unimpaired learners. Information is reviewed on principles of learning as they apply to impaired populations, current treatment designs are also reviewed that conform to the principles, and ways in which principles of learning might be incorporated into language treatment design are demonstrated. MAIN CONTRIBUTION: This paper provides an outline for how theoretical knowledge might be applied to clinical practice in an effort to promote discussion. CONCLUSIONS & IMPLICATIONS: Although the authors look forward to more specific details on how the principles of learning relate to impaired populations, there is ample evidence to suggest that these principles should be considered during treatment design.

Working Memory Predicts New Word Learning Over and Above Existing Vocabulary and Nonverbal IQ.

PURPOSE: The purpose of this study was to use an established model of working memory in children to predict an established model of word learning to determine whether working memory explained word learning variance over and above the contributions of expressive vocabulary and nonverbal IQ. METHOD: One hundred sixty-seven English-speaking second graders (7- to 8-year-olds) with typical development from two states participated. They completed a comprehensive battery of working memory assessments and six word learning tasks that assessed the creation, storage, retrieval, and production of phonological and semantic representations of novel nouns and verbs and the ability to link those representations. RESULTS: A structural equation model with expressive vocabulary, nonverbal IQ, and three working memory factors predicting two word learning factors fit the data well. When working memory factors were entered as predictors after expressive vocabulary and nonverbal IQ, they explained 45% of the variance in the phonological word learning factor and 17% of the variance in the semantic word learning factor. Thus, working memory explained a significant amount of word learning variance over and above expressive vocabulary and nonverbal IQ. CONCLUSION: Results show that working memory is a significant predictor of dynamic word learning over and above the contributions of expressive vocabulary and nonverbal IQ, suggesting that a comprehensive working memory assessment has the potential to identify sources of word learning difficulties and to tailor word learning interventions to a child's working memory strengths and weaknesses. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.19125911.

A lifespan perspective on semantic processing of concrete concepts: does a sensory/motor model have the potential to bridge the gap?

Research regarding semantic knowledge of objects is often conducted independently in children and adults. Review of these bodies of evidence suggests that the two literatures are often complementary. It seems critical to determine what we can learn from a developmental perspective, toward the common goal of understanding semantic organization. Here we focus on the proposal that semantic knowledge about concrete concepts may be built on the foundation of sensory/motor processes. In particular, we focus on a moderate formulation of this viewpoint, the sensory/motor model of semantic representations of objects (e.g., Gainotti 2007; Martin 2007), which has been examined utilizing behavioral, neuroimaging, and neuropsychological evidence. Taken together, behavioral and neuroimaging studies with infants, older children, and adults have suggested that patterns laid down in early childhood remain salient throughout the lifespan and may also predict patterns of deficit that emerge following brain injury.

A Vocabulary Acquisition and Usage for Late Talkers Treatment Efficacy Study: The Effect of Input Utterance Length and Identification of Responder Profiles.

Purpose This study examined the efficacy of the Vocabulary Acquisition and Usage for Late Talkers (VAULT) treatment in a version that manipulated the length of clinician utterance in which a target word was presented (dose length). The study also explored ways to characterize treatment responders versus nonresponders. Method Nineteen primarily English-speaking late-talking toddlers (aged 24-34 months at treatment onset) received VAULT and were quasirandomly assigned to have target words presented in grammatical utterances matching one of two lengths: brief (four words or fewer) or extended (five words or more). Children were measured on their pre- and posttreatment production of (a) target and control words specific to treatment and (b) words not specific to treatment. Classification and Regression Tree (CART) analysis was used to classify responders versus nonresponders. Results VAULT was successful as a whole (i.e., treatment effect sizes of greater than 0), with no difference between the brief and extended conditions. Despite the overall significant treatment effect, the treatment was not successful for all participants. CART results (using participants from the current study and a previous iteration of VAULT) provided a dual-node decision tree for classifying treatment responders versus nonresponders. Conclusions The input-based VAULT treatment protocol is efficacious and offers some flexibility in terms of utterance length. When VAULT works, it works well. The CART decision tree uses pretreatment vocabulary levels and performance in the first two treatment sessions to provide clinicians with promising guidelines for who is likely to be a nonresponder and thus might need a modified treatment plan. Supplemental Material https://doi.org/10.23641/asha.14226641.

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.

Using AAC to unlock communicative potential in late-talking toddlers.

PURPOSE: The purpose of this study was to report on modifications we made to a standardized input-based word learning treatment for two late-talking toddlers. The modifications were the addition of an augmentative alternative communication (AAC) device and the requirement that the children use this device, or speech, to communicate. METHOD: We used a single-subject design to track late-talking toddlers' progress through an input-based word learning treatment, which was part of a larger study. Because the input-based treatment protocol was not effective for each toddler based on absent or clinically insignificant treatment effect sizes, we modified the protocol. The modifications were meant to address each child's potential over-reliance on nonverbal communication and the potential impact of speech sound delay. We then measured their linguistic output. RESULTS: Both toddlers showed no evidence of learning during the input-based treatment. Each child's linguistic output increased by over 600 % once we made the protocol modification and introduced the AAC device. They used both AAC and vocal speech to communicate. Both toddlers produced novel words, and one began to produce multiple word combinations. DISCUSSION: While input-based therapy has an evidence base and has been successful for some toddlers, it may require modifications for children who have not learned the pragmatic convention of using spoken language, and for children with difficulty with speech sound production.

The Structure of Word Learning in Young School-Age Children.

Purpose We investigated four theoretically based latent variable models of word learning in young school-age children. Method One hundred sixty-seven English-speaking second graders with typical development from three U.S. states participated. They completed five different tasks designed to assess children's creation, storage, retrieval, and production of the phonological and semantic representations of novel words and their ability to link those representations. The tasks encompassed the triggering and configuration stages of word learning. Results Results showed that a latent variable model with separate phonological and semantic factors and linking indicators constrained to load on the phonological factor best fit the data. Discussion The structure of word learning during triggering and configuration reflects separate but related phonological and semantic factors. We did not find evidence for a unidimensional latent variable model of word learning or for separate receptive and expressive word learning factors. In future studies, it will be interesting to determine whether the structure of word learning differs during the engagement stage of word learning when phonological and semantic representations, as well as the links between them, are sufficiently strong to affect other words in the lexicon.

Exploring Input Parameters in an Expressive Vocabulary Treatment With Late Talkers.

Purpose The aims of this study were (a) to assess the efficacy of the Vocabulary Acquisition and Usage for Late Talkers (VAULT) treatment and (b) to compare treatment outcomes for expressive vocabulary acquisition in late talkers in 2 conditions: 3 target words/90 doses per word per session versus 6 target words/45 doses per word per session. Method We ran the treatment protocol for 16 sessions with 24 primarily monolingual English-speaking late talkers. We calculated a d score for each child, compared treatment to control effect sizes, and assessed the number of words per week children acquired outside treatment. We compared treatment effect sizes of children in the condition of 3 target words/90 doses per word to those in the condition of 6 target words/45 doses per word. We used Bayesian repeated-measures analysis of variance and Bayesian t tests to answer our condition-level questions. Results With an average treatment effect size of almost 1.0, VAULT was effective relative to the no-treatment condition. There were no differences between the different dose conditions. Discussion The VAULT protocol was an efficacious treatment that has the potential to increase the spoken vocabulary of late-talking toddlers and provides clinicians some flexibility in terms of number of words targeted and dose number, keeping in mind the interconnectedness of treatment parameters. Supplemental Material https://doi.org/10.23641/asha.11593323.

Spoken Word Learning Differences Among Children With Dyslexia, Concomitant Dyslexia and Developmental Language Disorder, and Typical Development.

Purpose The purpose of our study was to test the hypotheses (a) that children with dyslexia have spoken word learning deficits primarily related to phonology and (b) that children with dyslexia and concomitant developmental language disorder (DLD) have word learning deficits related to both phonology and semantic processing when compared to peers with typical development (TD). Method Second-graders with dyslexia (n = 82), concomitant dyslexia and DLD (dyslexia + DLD; n = 40), and TD (n = 167) learned names and semantic features for cartoon monsters in 5 carefully controlled word learning tasks that varied phonological and semantic demands. The computer-based tasks were played in 6 different word learning games. We analyzed results using Bayesian statistics. Results In general, the dyslexia + DLD group showed lower accuracy on tasks compared to the dyslexia and TD groups. As predicted, word learning tasks that taxed phonology revealed deficits in the dyslexia group, although there were some exceptions related to visual complexity. Word learning deficits in the dyslexia + DLD group were present in tasks that taxed phonology, semantic processing, or both. Conclusions The dyslexia + DLD group demonstrated word learning deficits across the range of word learning tasks that tapped phonology and semantic processing, whereas the dyslexia group primarily struggled with the phonological aspects of word learning. Supplemental Material https://doi.org/10.23641/asha.9807929.

Novel Word Learning in Children Who Are Bilingual: Comparison to Monolingual Peers.

Purpose We compared novel word learning in 2nd-grade children with typical development who were Spanish-English bilinguals to English monolinguals to understand word learning in bilingual children. Method Children (monolinguals n = 167, bilinguals n = 76) engaged in 5 computer-based tasks that assessed word learning in 6 different contexts. The tasks measured children's ability to link novel names with novel objects/actions, make decisions about the accuracy of those names and objects/actions, recognize the semantic features of the objects/actions, and produce the novel names. For analysis, we used Bayesian repeated-measures analyses of covariance with Bayesian independent-samples t tests to clarify interactions. Results Monolingual and bilingual children differed in some, but not most, word learning situations. There was at least moderate evidence that bilingual children were less accurate at naming in 1 condition and at detecting mispronunciations in 3 of 6 contexts and were less accurate at judging semantic features of a referent when that referent was paired with orthographic information. Discussion Among children with typical development, there were few differences in novel word learning between monolingual and bilingual participants. When differences did occur, they suggested that bilinguals were more accepting of phonological variations of word productions than their monolingual peers.

Working Memory Profiles of Children With Dyslexia, Developmental Language Disorder, or Both.

Purpose Compared to children with typical development, children with dyslexia, developmental language disorder (DLD), or both often demonstrate working memory deficits. It is unclear how pervasive the deficits are or whether the deficits align with diagnostic category. The purpose of this study was to determine whether different working memory profiles would emerge on a comprehensive battery of central executive, phonological, visuospatial, and binding working memory tasks and whether these profiles were associated with group membership. Method Three hundred two 2nd graders with typical development, dyslexia, DLD, or dyslexia/DLD completed 13 tasks from the Comprehensive Assessment Battery for Children-Working Memory ( Gray, Alt, Hogan, Green, & Cowan, n.d. ) that assessed central executive, phonological, and visuospatial/attention components of working memory. Results Latent class analyses yielded 4 distinct latent classes: low overall (21%), average with high number updating (30%), average with low number updating (12%), and high overall (37%). Children from each disability group and children from the typically developing group were present in each class. Discussion Findings highlight the importance of knowing an individual child's working memory profile because working memory profiles are not synonymous with learning disabilities diagnosis. Thus, working memory assessments could contribute important information about children's cognitive function over and above typical psychoeducational measures.

Statistical Learning: How it Relates to Speech-Language Pathology.

Purpose: The purpose of this special issue is to introduce speech-language pathologists to the topic of statistical learning and how this is relevant to their practice. In the following articles, the concept of statistical learning will be explained, and readers will find (a) research studies showing how children with special needs can use statistical learning to learn language; (b) tutorials that show why statistical learning is meaningful for special populations; and (c) tutorials that show how statistical learning is involved in language, reading, and spelling.

Take Home Points: How to Use Statistical Learning.

Purpose: The purpose of this epilogue is to synthesize the main points of the articles in this issue on statistical learning for clinicians. These points can be used to guide practice.