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Background and aims Current evidence shows that children with developmental language disorder (DLD) benefit from spaced retrieval during word learning activities. Word recall is quite good relative to recall with alternative word learning procedures. However, recall on an absolute basis can be improved further; many studies report that fewer than two-thirds of the words are learned, even with the assistance of spaced retrieval during the learning activities. In this article we identify details of spaced retrieval that are less well understood in an effort to promote more effective learning through retrieval practice. Main contribution We discuss the importance of factors such as: (a) integrating immediate retrieval with spaced retrieval trials; (b) determining whether gradual increases in spacing have more than short-term benefits relative to equal spacing; (c) discovering the number of successful retrievals sufficient to ensure later recall; (d) using spaced retrieval to avoid erosion of phonetic details on later recall tests; and (e) whether the well-documented difficulties with learning word forms might be tied to a particular subgroup of children with DLD. We also speculate on some of the possible reasons why spaced retrieval is beneficial in the first place. Conclusions Although many children with DLD make gains in word learning through procedures that incorporate spaced retrieval, there are numerous details involved in the process that can alter its success. Until we have a better understanding of the boundaries of spaced retrieval's effectiveness, we will not be taking full advantage of this promising addition to word learning procedures. Implications Spaced retrieval activities can be an important addition to the resources that clinicians and educators have available to assist children in their word learning. With a deeper understanding of the issues discussed here, we should be able to put spaced retrieval to even greater use.

Abstract Background Many children with developmental language disorders (DLD) have well-documented weaknesses in vocabulary. In recent years, investigators have explored the nature of these weaknesses through the use of novel word learning paradigms. These studies have begun to uncover specific areas of difficulty and have provided hints about possible intervention strategies that might help these children learn words more accurately and efficiently. Among the studies of this type are those that incorporate repeated spaced retrieval activities in the learning procedures. Methods In this study, we examined the data from four of these studies that employed the same types of participants (4- and 5-year-old children with DLD and same-age children with typical language development), research design, and outcome measures. The studies differed primarily in the type of learning condition that was being compared to a spaced retrieval condition. A mixed-effects modeling framework was used, enabling the data from the four studies and different outcome measures to be aggregated. Results Across the studies, more words in the repeated spaced retrieval condition were recalled than those in the comparison conditions. This was true regardless of outcome measure. Children with typical language development recalled more words than the children with DLD. Both groups benefited from spaced retrieval, though effects were larger for the group with DLD. Children recalled words as accurately 1 week after learning as they did at the 5-min mark; the two groups were essentially identical in this respect. Conclusions Overall, the findings support the continued refinement of these types of repeated spaced retrieval procedures, as they may have potential to serve as effective approaches to intervention.

Abstract Due to wide variability of typical language development, it has been historically difficult to distinguish typical and delayed trajectories of early language growth. Improving our understanding of factors that signal language disorder and delay has the potential to improve the lives of the millions with developmental language disorder (DLD). We develop predictive models of low language (LL) outcomes by analyzing parental report measures of early language skill using machine learning and network science approaches. We harmonized two longitudinal datasets including demographic and standardized measures of early language skills (the MacArthur-Bates Communicative Developmental Inventories; MBCDI) as well as a later measure of LL. MBCDI data was used to calculate several graph-theoretic measures of lexico-semantic structure in toddlers’ expressive vocabularies. We use machine-learning techniques to construct predictive models with these datasets to identify toddlers who will have later LL outcomes at preschool and school-age. This approach yielded robust and reliable predictions of later LL outcome with classification accuracies in single datasets exceeding 90%. Generalization performance between different datasets was modest due to differences in outcome ages and diagnostic measures. Grammatical and lexico-semantic measures ranked highly in predictive classification, highlighting promising avenues for early screening and delineating the roots of language disorders.

Background and Aims Children with developmental language disorder (DLD) benefit from word learning procedures that include a mix of immediate retrieval and spaced retrieval trials. In this study, we examine the relative contribution of these two types of retrieval. Methods We examine data from Haebig et al. (2019) in their study that compared an immediate retrieval condition and a condition of spaced retrieval that also included immediate retrieval trials. Participants were 4- and 5-year old children with DLD and same-age peers with typical language development. Each child learned novel (made-up) words referring to unusual plants and animals in both conditions. We examined the phonetic accuracy of the novel words used during the final learning trial and during recall tests 5 min and 1 week after learning. Results On the final learning trial, the children were more phonetically accurate in using the novel words learned in the immediate retrieval condition. However, recall tests after the learning trials revealed a decrease in accuracy, especially for the children with DLD. After one week, accuracy was much lower for words in the immediate retrieval condition than for words in the mixed spaced-plus-immediate retrieval condition. For words learned in the mixed spaced-plus-immediate retrieval condition, accuracy was very stable across time for both groups. Conclusions Immediate retrieval boosts the phonetic accuracy of new words in the short term but spaced retrieval promotes stability and increases the likelihood that short-term gains are maintained. Implications: When novel word learning is assessed at the level of phonetic accuracy, children with DLD can show declines over time not characteristic of children with typical language development. Spaced retrieval procedures augmented by immediate retrieval opportunities during learning appear to prevent such declines, leading to longer-lasting gains.

Purpose: Children with developmental language disorder (DLD) tend to interpret noncanonical sentences like passives using event probability (EP) information regardless of structure (e.g., by interpreting "The dog was chased by the squirrel" as "The dog chased the squirrel"). Verbs are a major source of EP information in adults and children with typical development (TD), who know that "chase" implies an unequal relationship among participants. Individuals with DLD have poor verb knowledge and verb-based sentence processing. Yet, they also appear to rely more on EP information than their peers. This paradox raises two questions: (a) How do children with DLD use verb-based EP information alongside other information in online passive sentence interpretation? (b) How does verb vocabulary knowledge support EP information use? Method: We created novel EP biases by showing animations of agents with consistent action tendencies (e.g., clumsy vs. helpful actions). We then used eye tracking to examine how this EP information was used during online passive sentence processing. Participants were 4- to 5-year-old children with DLD (n = 20) and same-age peers with TD (n = 20). Results: In Experiment 1, children with DLD quickly integrated verb-based EP information with morphosyntax close to the verb but failed to do so with distant morphosyntax. In Experiment 2, the quality of children's sentence-specific verb vocabulary knowledge was positively associated with the use of EP information in both groups. Conclusion: Depending on the morphosyntactic context, children with DLD and TD used EP information differently, but verb vocabulary knowledge aided its use.

Purpose: The word learning of preschool-age children with developmental language disorder (DLD) is improved when spaced retrieval practice is incorporated into the learning sessions. In this preregistered study, we compared two types of spacing--an expanding retrieval practice schedule and an equally spaced schedule--to determine if one of these approaches yields better word learning outcomes for the children. Method: Fourteen children with DLD aged 4-5 years and 14 same-age children with typical language development (TD) learned eight novel nouns over two sessions. Spacing for half of the novel words was expanded gradually during learning; for the remaining novel words, greater spacing remained at the same level throughout learning. Immediately after the second session and 1 week later, the children's recall of the words was tested. Results: The children with TD recalled more novel words than the children with DLD, although this difference could be accounted for by differences in the children's standardized receptive vocabulary test scores. The two groups were similar in their ability to retain the words over 1 week. Initially, the shorter spacing in the expanding schedule resulted in greater retrieval success than the corresponding (longer spaced) retrieval trials in the equally spaced schedule. These early shorter spaced trials also seemed to benefit retrieval of the trials with greater spacing that immediately followed. However, as the learning period progressed, the accuracy levels for the two conditions converged and were likewise similar during final testing. Conclusion: We need a greater understanding of how and when short spacing can be helpful to children's word learning, with the recognition that early gains might give a misleading picture of the benefits that short spacing can provide to longer term retention.

Abstract Background A substantial amount of work has examined language abilities in young children with specific language impairment (SLI); however, our understanding of the developmental trajectory of language impairment is limited. Along with studying the behavioral changes that occur across development, it is important to examine the neural indices of language processing for children with different language trajectories. The current study sought to examine behavioral and neural bases of language processing in adolescents showing three different trajectories: those with normal language development (NL), those exhibiting persistent SLI (SLI-Persistent), and those with a history of SLI who appear to have recovered (SLI-Recovered). Methods Through a sentence judgment task, we examined semantic and syntactic processing. Adolescents judged whether or not each sentence was semantically and syntactically correct. Stimuli consisted of naturally spoken sentences that were either correct, contained a semantic verb error, or contained a syntactic verb agreement error. Verb agreement errors consisted of omission and commission violations of the third-person singular -s. Behavioral button-press responses and electroencephalographic recordings were collected. Behavioral judgments and mean amplitude of the N400 and P600 components were examined. Results Adolescents in the SLI-Persistent group had lower sentence judgment accuracy overall, relative to the NL and SLI-Recovered groups. Accuracy in judging omission and commission syntactic errors were marginally different, with marginally lower accuracy for commission errors. All groups demonstrated an N400 component elicited by semantic violations. However, adolescents in the SLI-Persistent group demonstrated a less robust P600 component for syntactic violations. Furthermore, adolescents in the SLI-Recovered group exhibited a similar neural profile to the NL group for the semantic and syntactic omission violations. However, a unique profile with initial negativity was observed in the SLI-Recovered group in the commission violation condition. Conclusions Adolescents with persistent language impairment continue to demonstrate delays in language processing at the behavioral and neural levels. Conversely, the adolescents in the SLI-Recovered group appear to have made gains in language processing skills to overcome their initial impairments. However, our findings suggest that the adolescents in the SLI-Recovered group may have compensatory processing strategies for some aspects of language, as evidenced by a unique event-related potential profile.

The main goal of this tutorial is to promote the study of children with developmental language disorder (DLD) across different languages of the world. The cumulative effect of these efforts is likely to be a set of more compelling and comprehensive theories of language learning difficulties and, possibly, of language acquisition in general. Benefits to children and local societies are also likely to accrue. After presenting some of the initial considerations involved in the cross-linguistic study of children with language disorders, we provide examples of the types of questions that might be asked. The examples are informed by our own collaborative work studying children DLD across the languages of Cantonese, Finnish, German, Hebrew, Hungarian, Italian, Spanish, Swedish, and Turkish, as well as English. Examples from investigators' work on other languages are also included. We discuss within-language comparisons of children with DLD and their same-age and younger typically developing peers as well as between-language comparisons of children with DLD. Examples concern issues of morphophonology, prosody, syntactic movement, verb paradigm complexity, and underlying mechanisms, among others. These examples--tied as they are to current theories and hypotheses--are necessarily limited to the types of languages already receiving investigative attention. Through the participation of child language scholars from a wider set of disciplines we can expand the number and types of languages studied and, as a consequence, greatly enhance our understanding of childhood language disorders.