Word learning and verbal working memory in children with developmental language disorder

Word Learning in Arabic Diglossia in Children With Typical Language Development and Developmental Language Disorder

PURPOSE

Word learning requires the creation of phonological and semantic representations and links in long-term memory. Phonological distance of a given word from the spoken language affects children's lexical-phonological representations and processing. The study investigates the role of the phonological distance of Modern Standard Arabic (StA) words from the child's Spoken Arabic (SpA) vernacular in word learning in Arabic diglossia. It also examines whether, given their vulnerable phonological skills, children with developmental language disorder (DLD) show a stronger impact of phonological distance on word learning than children with typical language development (TLD).

METHOD

One hundred children with TLD and DLD in kindergarten and in first grade (25 per group) were tested on comprehension and production word-learning probes manipulating phonological distance. Learning monosyllabic and disyllabic nonwords encoding only SpA phonemes was compared with the learning of parallel nonwords encoding one unique StA consonant each.

RESULTS

Repeated-measures analyses of variance showed higher word learning scores in children with TLD on both probes and for both syllable lengths. Moreover, all children fared significantly lower, in both comprehension and production probes, when the target stimulus was phonologically distant from the spoken language. Finally, an interaction effect was observed on the production probes, revealing differences in the developmental dynamics of phonological distance effects between the groups: Phonological distance hindered word learning among children with TLD in kindergarten, but among children with DLD in the first grade.

CONCLUSIONS

The results support the role of phonological distance as a phonological complexity factor in word learning in Arabic diglossia. Furthermore, they show that the effect of phonological distance is complex and it interacts with modality, language aptitude, and grade level. The theoretical and clinical implications are discussed.

Learning Verbs in Sentences: Children With Developmental Language Disorder and the Role of Retrieval Practice

PURPOSE

Retrieval practice has been shown to assist the word learning of children with developmental language disorder (DLD). Although this has been true for learning new verbs as well as new nouns and adjectives, these children's overall verb learning has remained quite low. In this preregistered study, we presented novel verbs in transitive sentences with varying subjects/agents and objects/patients to determine if recall could be improved and if retrieval practice continued to be facilitative.

METHOD

Fourteen children with DLD aged 4-5 years and 13 same-age peers with typical language development (TD) learned eight novel verbs over two sessions. Half of the novel verbs were presented with spacing between study and retrieval trials, and half were presented with the same frequency in study trials without the opportunity for retrieval. All novel verbs were presented in sentences such as, "The woman is deeking the shoe." Children's ability to recall and use the novel verbs in the same sentence structure was tested after the second session and 1 week later. The children were also required to use the novel verbs in bare-stem form in a new structure, as in, "That woman likes to deek the towel."

RESULTS

Both groups of children showed increased recall relative to a previous novel verb study. The children with TD showed the expected advantages of spaced retrieval over repeated study and could use the novel verbs in the new morphological form and sentence structure. The children with DLD, however, showed an advantage for spaced retrieval only shortly after the learning period. These children had great difficulty changing the novel verbs to a bare stem and using them in a new structure.

CONCLUSION

Although spaced retrieval assists children's novel verb recall, children with DLD in particular require additional help using these verbs with morphological and syntactic flexibility.

Executive functions in children with developmental language disorder: a systematic review and meta-analysis

Background

The purpose of the current study was to assess the differences between children with developmental language disorder (DLD) and typically developing (TD) children in their performance of executive functions from working memory, inhibitory control, and cognitive flexibility.

Methods

We performed a systematical search of PubMed, Embase, Cochrane, and Web of Science for case control studies (published in English between January 1, 1950, and October 11, 2023) comparing the differences in the performance of executive functions between DLD and TD children.

Results

Forty eligible studies were included in the present study (N = 3,168 participants). In comparison with TD children, DLD children exhibited significantly poorer performances in all six verbal working memory tasks (backward digit recall task, SMD -1.4321, 95% CI -2.2692 to -0.5950; listening recall task, SMD -1.4469, 95% CI -1.7737 to -1.1202; counting recall task, SMD -0.9192, 95% CI -1.4089 to -0.4295; digit recall task, SMD -1.2321, 95% CI -1.4397 to -1.0244; word list recall task, SMD -1.1375, 95% CI -1.5579 to -0.7171; non-word recall task, SMD -1.5355, 95% CI -1.8122 to -1.2589). However, regarding inhibitory control and cognitive flexibility, the differences between DLD and TD children depended on specific circumstances. In subgroup analyses of all verbal working memory tasks, DLD children presented notably lower performance than TD children in both the monolingual English and monolingual non-English groups, and in both the preschooler and school-aged groups.

Conclusion

This study proves that verbal working memory deficits can be seen as a marker for children with DLD and are not affected by age or language type.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=391070, CRD42023391070.

Individual Predictors of Language Treatment Response in Children With Developmental Language Disorder: A Systematic Review

PURPOSE

Treatment response is the degree to which an individual benefits from a treatment. This systematic review sought to identify and synthesize research evidence regarding individual characteristics that predict language treatment response among children with developmental language disorder (DLD).

METHOD

To be eligible for inclusion, articles needed to report results of an oral language treatment program in a group of children aged 4-10 years with identified DLD and also include a quantitative analysis of the relation between one or more pretreatment child characteristics and the outcome of language treatment. Seven databases (Cumulated Index to Nursing and Allied Health Literature, Dissertations and Theses Global, Education Resources Information Center, Linguistics and Language Behavior Abstracts, PsycINFO, Medline, and Web of Science) were searched for articles in June and July 2021, with search updates conducted in May 2023. Studies were categorized by the type of treatment provided, and results were synthesized qualitatively.

RESULTS

The review included 31 studies, 1,551 participants with DLD, and over 300 statistical tests of a predictor's effect on language treatment response. Most studies (n = 21) included only monolingual speakers of English, with five studies including bilinguals and five including monolingual speakers of non-English languages. Language treatments targeted word learning in controlled or clinical conditions, grammatical learning in controlled or clinical conditions, or multiple language targets in clinical conditions. Predictors of treatment response are summarized across four categories: cognitive, demographic, pretreatment language levels, and other.

CONCLUSIONS

There were relatively few significant tests of the predictors of language treatment response. A central limitation of the evidence is that most included studies were designed to consider language treatment efficacy, not predictors of treatment response. Increasing research attention to the question of predictors of language treatment response in children with DLD is needed to enhance treatment and optimize outcomes for individual children.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.26170006.

Spoken verb learning in children with language disorder

The current study examined spoken verb learning in elementary school children with language disorder (LD). We aimed to replicate verb learning deficits reported in younger children with LD and to examine whether verb instrumentality, a semantic factor reflecting whether an action requires an instrument (e.g., "to chop" is an instrumental verb), influenced verb learning. The possible facilitating effect of orthographic cues presented during training was also evaluated. In an exploratory analysis, we investigated whether language and reading skills mediated verb learning performance. General language skills and verb learning were assessed in Dutch children with LD and age-matched typically developing controls (n = 25 per group) aged 8 to 12 years (M = 9;9 [years;months], SD = 1;3). Using video animations, children learned 20 nonwords depicting actions comprising 10 instrumental and 10 noninstrumental verbs. Half of the items were trained with orthographic information present. Verb learning was assessed using an animation-word matching and animation naming task. Linear mixed-effects models showed a main effect of group for all verb learning measures, demonstrating that children with LD learned fewer words and at a slower rate than the control group. No effect of verb instrumentality, presence of orthographic information, or the included mediators was found. Our results emphasize the importance of continued vocabulary instruction in elementary school to strengthen verb encoding. Given that our findings are inconsistent with the overall literature showing an orthographic facilitation effect, future studies should investigate whether participants pay attention to the written word form in learning contexts with moving stimuli.

Lexical-semantic processing in preschoolers with Developmental Language Disorder: an eye tracking study

This study examined lexical-semantic processing in children with Developmental Language Disorder (DLD) during visually situated comprehension of real-time spoken words. Existing evidence suggests that children with DLD may experience challenges in lexical access and retrieval, as well as greater lexical competition compared to their peers with Typical Development (TD). However, the specific nature of these difficulties remains unclear. Using eye-tracking methodology, the study investigated the real-time comprehension of semantic relationships in children with DLD and their age-matched peers. The results revealed that, for relatively frequent nouns, both groups demonstrated similar comprehension of semantic relationships. Both groups favored the semantic competitor when it appeared with an unrelated visual referent. In turn, when the semantic competitor appeared with the visual referent of the spoken word, both groups disregarded the competitor. This finding shows that, although children with DLD usually present a relatively impoverished vocabulary, frequent nouns may not pose greater difficulties for them. While the temporal course of preference for the competitor or the referent was similar between the two groups, numerical, though non-significant, differences in the extension of the clusters were observed. In summary, this research demonstrates that monolingual preschoolers with DLD exhibit similar lexical access to frequent words compared to their peers with TD. Future studies should investigate the performance of children with DLD on less frequent words to provide a comprehensive understanding of their lexical-semantic abilities.

Retrieval Practice and Word Learning by Children With Developmental Language Disorder: Does Expanding Retrieval Provide Additional Benefit?

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.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25537696.

Word learning by children with developmental language disorder: Identifying gaps in our understanding of spaced retrieval effects

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.

The 10-Word Auditory Verbal Learning Test and Vocabulary Performance in 4- and 5-Year-Old Children

BACKGROUND

Understanding the different factors that determine vocabulary development in young children is essential for the diagnosis and rehabilitation of language disorders in children. Language development is closely related to other cognitive processes such as auditory verbal learning and memory. This research focuses on the development of a novel auditory verbal learning test (AVLT) for 4- and 5-year-old children within the Dutch population. This new test is an adaptation of the common AVLT for both older children and adults, usually including a list of 15 words. Considering the lower attention span and limited executive functioning in young children, the word list of this new instrument is reduced to 10 words. Besides, a second recognition form has been developed to improve the ability to distinguish between possible underlying learning and memory deficits.

METHOD

Ninety-five preschool children (ages 4;0-5;12 [years;months]) were tested with this new AVLT 10-word test for kids (10WT-K), yielding different measures of verbal auditory memory. Forty-eight of 95 children received a recognition task with semantically unrelated items, and 47 of 95 received a recognition task with semantically related items. Three additional language skills were assessed to establish test validation: receptive and expressive vocabulary performance and nonword repetition. Outcome of the 10WT-K was related to scores on the language measures.

RESULTS

Positive correlations were found between the total score of the 10WT-K and all three aforementioned language skills. We found no correlations between frequency of error types (intrusions and repetitions) and language measures. Furthermore, children who were administered the recognition list with semantically related items showed fewer correct answers and more false-positive and false-negative responses than children who received a recognition list with semantically unrelated items.

CONCLUSIONS

The 10WT-K for young children can be used to (a) measure different aspects of auditory verbal learning and memory, (b) clarify the nature of possible verbal learning difficulties, and (c) identify a possible nature of language disorders. The word recognition task tested with semantically related items provides a more accurate measurement of individual differences, namely, in distinguishing retrieval and storage abilities. The significant relation found between auditory verbal short-term memory capacity and vocabulary performance in preschool children is a first step toward establishing test validity.

Nonverbal Executive Functioning in Relation to Vocabulary and Morphosyntax in Preschool Children With and Without Developmental Language Disorder

PURPOSE

Developmental language disorder (DLD) is characterized by persistent and unexplained difficulties in language development. Accumulating evidence shows that children with DLD also present with deficits in other cognitive domains, such as executive functioning (EF). There is an ongoing debate on whether exclusively verbal EF abilities are impaired in children with DLD or whether nonverbal EF is also impaired, and whether these EF impairments are related to their language difficulties. The aims of this study were to (a) compare nonverbal performance of preschoolers with DLD and typically developing (TD) peers, (b) examine how nonverbal EF and language abilities are related, and (c) investigate whether a diagnosis of DLD moderates the relationship between EF and language abilities.

METHOD

A total of 143 children (nDLD = 65, nTD = 78) participated. All children were between 3 and 6.5 years old and were monolingual Dutch. We assessed nonverbal EF with a visual selective attention task, a visuospatial short-term and working memory task, and a task gauging broad EF abilities. Vocabulary and morphosyntax were each measured with two standardized language tests. We created latent variables for EF, vocabulary, and morphosyntax.

RESULTS

Analyses showed that children with DLD were outperformed by their TD peers on all nonverbal EF tasks. Nonverbal EF abilities were related to morphosyntactic abilities in both groups, whereas a relationship between vocabulary and EF skills was found in the TD group only. These relationships were not significantly moderated by a diagnosis of DLD.

CONCLUSIONS

We found evidence for nonverbal EF impairments in preschool children with DLD. Moreover, nonverbal EF and morphosyntactic abilities were significantly related in these children. These findings may have implications for intervention and support the improvement of prognostic accuracy.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24121287.

Can Retrieval Practice Facilitate Verb Learning in Children With Developmental Language Disorder and Their Peers With Typical Language Development?

PURPOSE

Children with developmental language disorder (DLD) have well-documented verb learning difficulties. In this study, we asked whether the inclusion of retrieval practice during the learning period would facilitate these children's verb learning relative to a similar procedure that provided no retrieval opportunities.

METHOD

Eleven children with DLD (M age = 60.09 months) and 12 children with typical language development (TD; M age = 59.92 months) learned four novel verbs in a repeated spaced retrieval (RSR) condition and four novel verbs in a repeated study (RS) condition. The words in the two conditions were heard an equal number of times, in the context of video-recorded actors performing novel actions.

RESULTS

Recall testing immediately after the learning period and 1 week later revealed greater recall for novel verbs in the RSR condition than for novel verbs in the RS condition. This was true for both groups, and for immediate as well as 1-week testing. The RSR advantage remained when children had to recall the novel verbs while watching new actors perform the novel actions. However, when tested in contexts requiring the children to inflect the novel verbs with -ing for the first time, the children with DLD were much less likely to do so than their peers with TD. Even words in the RSR condition were only inconsistently inflected.

CONCLUSIONS

Retrieval practice provides benefits to verb learning-an important finding given the challenges that verbs present to children with DLD. However, these benefits do not appear to automatically translate to the process of adding inflections to newly learned verbs but rather appear to be limited to the operations of learning the verbs' phonetic forms and mapping these forms onto associated actions.

Direct Instruction Improves Word Learning for Children With Developmental Language Disorder

PURPOSE

The current study compared the effects of direct instruction versus indirect exposure on multiple aspects of novel word learning for children with developmental language disorder (DLD) and children with typical language development (TLD).

METHOD

Participants included 36 children with DLD and 45 children with TLD. All children were in the first grade and 6-8 years of age (Mdn = 7 years; 2 months). Using a between-subjects design, children were randomly assigned to be exposed to novel words and their unfamiliar referents via either direct instruction (each referent presented in isolation with an explicit goal of learning) or indirect exposure (multiple referents presented with the goal of answering yes/no questions).

RESULTS

In alternative forced-choice measures of recognition, children with DLD were less accurate than their TLD peers in linking words to referents, encoding semantic categories for words, and encoding detailed representations of word forms. These differences in word learning were accounted for by a constellation of cognitive measures, including receptive vocabulary, phonological memory, visuospatial memory, and sustained attention. All children were similarly accurate in retaining word forms over a 24- to 48-hr delay. Children with TLD were more accurate in all aspects of word learning following direct instruction compared to indirect exposure. Benefits from direct instruction were observed for children with DLD in link and semantic, but not word form, learning.

CONCLUSIONS

These results suggest that vocabulary interventions with direct instruction can help children with DLD learn some, but not all, aspects of novel words. Additional support is necessary to help children with DLD encode rich phonological representations.

The Contributions of Immediate Retrieval and Spaced Retrieval to Word Learning in Preschoolers with Developmental Language Disorder

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.