Structural Relationship Between Cognitive Processing and Syntactic Sentence Comprehension in Children With and Without Developmental Language Disorder

Verb Vocabulary Supports Event Probability Use in Developmental Language Disorder

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.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25491805.

Enhancing Syntactic Knowledge in School-Age Children With Developmental Language Disorder: The Promise of Syntactic Priming

PURPOSE

We propose that implicit learning, including syntactic priming, has therapeutic promise to enhance the syntactic knowledge of children with developmental language disorder (DLD).

METHOD

We review the chunk-based learning framework of syntactic learning, the developmental evidence in support of it, and the developmental literature on syntactic priming as an instance of chunk-based statistical learning. We use this framework to help understand the nature of the syntactic learning difficulties of children with DLD. We then briefly review the available explicit treatments for syntactic deficits and end by proposing an implicit training activity that integrates syntactic priming with the principles of statistical learning.

RESULTS

Statistically induced chunk-based learning is a powerful driver of syntactic learning, and syntactic priming is a form of this learning. Repeated priming episodes during everyday language interactions lead children to create abstract and global syntactic representations in long-term memory. We offer some thoughts on an implicit language intervention approach with syntactic priming at its center.

CONCLUSIONS

Children's learning of syntactic structures is influenced by repeated syntactic priming experiences. Including a syntactic priming activity in our language intervention toolbox has the promise to enhance children's syntactic knowledge and sentence comprehension and production abilities.

Sentences Are Key: Helping School-Age Children and Adolescents Build Sentence Skills Needed for Real Language

PURPOSE

In this article, we present key concepts pointing to the importance of targeting complex sentences for school-age children and adolescents with developmental language disorders (DLD). Drawing on current treatment research, we argue that the sentence is a crucial but often neglected piece of the puzzle when it comes to understanding relationships between DLD and academic outcomes. We provide detailed suggestions for how clinicians can focus on complex sentence structures in natural academic contexts to bridge this gap.

METHOD

Background information on sentence complexity is presented, along with a rationale for targeting complex sentences with school-age children and adolescents with DLD. Intervention methods from a variety of studies targeting multiclausal sentences are discussed in relation to current accounts of language learning and language processing models. We provide a robust catalog of suggested strategies for targeting sentence complexity in a manner that is aligned with research findings to date and integrated into real academic contexts.

CONCLUSIONS

Complex sentence structures are a key challenge for students with DLD as they tackle discipline-specific language and academic tasks. Sentence complexity treatment programs employ one or more treatment methods including priming, modeling, recasting, contextualization, metalinguistic instruction, and sentence combining. While studies have consistently shown a measurable improvement in complex sentence production on proximal outcomes regardless of treatment approach, evidence of durable, functional changes for students with DLD remains sparse. We encourage new treatments that target comprehension and production of complex sentences in real-life academic contexts in clinical practice and research.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23969103.

Comprehension of complex syntax by non-English-speaking children with developmental language disorder: A scoping review

Children with developmental language disorder (DLD) are characterised by impaired language abilities both in comprehension and production. Complex syntax is a specific domain which is often considered challenging for children with DLD. Research regarding complex syntax is mostly concerned with the production patterns of speakers and usually employs English-speaking populations. This scoping review aims to systematically map the abilities of non-English-speaking children with DLD to comprehend complex syntactic structures, comparing these results with the broader literature on English-speaking children with DLD. It also aims to consider the account (i.e. grammatical vs processing) by which these abilities can be explained. Four online databases were used to extract original research articles published between 2011 and 2021. Of the 264 studies initially identified, 20 studies were included in the review. The results demonstrated that children with DLD present with difficulties in comprehending object relative clauses, wh-questions, sentences with non-canonical word order, passives, and other types of complex syntax. All of these challenges are also evident in English-speaking children with DLD and can be mainly attributed either to the inability of children to assign thematic roles, their restricted working memory capacities, or a combination thereof. It is concluded that the comprehension of complex syntax might be a universal marker of DLD, which can be explained on the basis of either a grammatical or a processing account, or both. Common challenges in certain structures across languages can be used to design a comprehension assessment tool that can be applied in several languages.

The significance of nonverbal performance in children with developmental language disorder

Nonverbal deficits are frequently reported in children with developmental language disorder (DLD). In the new diagnostic criteria of DLD, the previous requirement of normal nonverbal performance has been removed and children with below average and even weak nonverbal skills now fit under the DLD definition. However, the significance of the nonverbal cognitive level, and the connection between nonverbal and verbal skills in these children diagnosed according to the new DLD classification is unclear. In the present study, the significance of nonverbal cognitive level on verbal performance was investigated among preschool-aged children with remarkable deficits in language development. Verbal skills were compared between average, below average, and weak nonverbal cognitive level groups. The connection between nonverbal and verbal skills was evaluated with Pearson correlations, and the covariance structure of the subtests used was modeled with Structural Modelling. The connection between nonverbal cognitive level and verbal skills was clear; weaker nonverbal cognitive levels were associated with lower verbal skills. While receptive language skills and verbal short-term-memory (STM) were the most profound weaknesses, relative strengths emerged for each nonverbal cognitive level group in fluid intelligence, especially in nonverbal reasoning tasks without time limits. In addition, fluid intelligence was strongly linked to verbal understanding and reasoning. These results suggest that the relative strength in nonverbal fluid intelligence with specific weaknesses in receptive language, verbal understanding, and verbal STM could be used as basic factors differentiating children with DLD from those with intellectual disability.

The effect of sentence length on question comprehension in children with cochlear implants

OBJECTIVES

The present study investigated the comprehension of subject and object who and which questions in children with cochlear implants (CI).

METHODS

Growth Curve Analysis (GCA) was used to compare eye gaze fixations and gaze patterns to the appropriate subject or object nouns within a four-picture array between 16 children with CI and 31 children with typical hearing (aged 7;0-12;0) on wh-questions with and without added adjectives to increase length. Offline accuracy was also compared.

RESULTS

Findings indicated children with typical hearing exhibited more fixations to the target noun across all conditions, supporting higher comprehension accuracy. Both groups of children demonstrated more fixations to the target noun in object questions and questions without added length. Patterns of eye movement were significantly different between groups, suggesting different patterns of eye gaze across the array before fixation on the target noun. Children with CI exhibited fewer fixations, slower speed to fixation, and differences in gaze patterns that may imply the presence of processing limitations. Error analyses also suggested that children with CI frequently fixated on a picture similar to the target noun.

CONCLUSIONS

Results indicate children with CI comprehend questions more slowly than their hearing peers, which may be related to limitations in working memory.

Predictors of language proficiency in school-age Spanish-English bilingual children with and without developmental language disorder

Children with developmental language disorder (DLD) have impairments in their language-learning abilities that may influence interactions with environmental opportunities to learn two languages. This study explores relationships between proficiency in L1 and L2 and a set of environmental and personal variables within a group of school-age Spanish-English bilingual children with DLD and a group of typically-developing peers. Within each group, current usage in the home, length of L2 exposure, gender, maternal education, analytical reasoning, and number of L1 conversational partners were used to predict proficiency in each language. Results showed that home language environment, particularly home L2 usage, strongly predicted L1 proficiency but had less influence on the L2. Female gender predicted L1 skills in both groups, whereas analytical reasoning predicted both L1 and L2 but only for children with DLD. This study expands the limited literature on how children with DLD interact with their environment to learn two languages.

Children's syntactic parsing and sentence comprehension with a degraded auditory signal

During sentence comprehension, young children anticipate syntactic structures using early-arriving words and have difficulties revising incorrect predictions using late-arriving words. However, nearly all work to date has focused on syntactic parsing in idealized speech environments, and little is known about how children's strategies for predicting and revising meanings are affected by signal degradation. This study compares comprehension of active and passive sentences in natural and vocoded speech. In a word-interpretation task, 5-year-olds inferred the meanings of novel words in sentences that (1) encouraged agent-first predictions (e.g., The blicket is eating the seal implies The blicket is the agent), (2) required revising predictions (e.g., The blicket is eaten by the seal implies The blicket is the theme), or (3) weakened predictions by placing familiar nouns in sentence-initial position (e.g., The seal is eating/eaten by the blicket). When novel words promoted agent-first predictions, children misinterpreted passives as actives, and errors increased with vocoded compared to natural speech. However, when familiar words were sentence-initial that weakened agent-first predictions, children accurately interpreted passives, with no signal-degradation effects. This demonstrates that signal quality interacts with interpretive processes during sentence comprehension, and the impacts of speech degradation are greatest when late-arriving information conflicts with predictions.

Animacy-induced conflict in sentence production and comprehension from late childhood to adolescence

Some animacy configurations elicit parallel semantic interference in adult production and comprehension; for example, phrases with similar animate nouns like the man that the girl is hugging are more difficult than phrases like the doll that the girl is hugging. Yet little is known about how this interference manifests in development, particularly, beyond early childhood. Because frontal brain maturation and cognitive control improvements are known to occur across late childhood and adolescence, we investigated (a) how animacy-induced difficulty in production and comprehension vary with age throughout this period and (b) whether control processes reflected in the backward digit span (BDS) test uniquely explained these differences besides other language measures. In separate tasks, participants (8- to 15-year-old children; N = 91) heard auditory descriptions of depicted characters, produced characters' descriptions, and completed BDS, vocabulary, and reading experience tests. Results indicated that, as in adults, animacy modulated performance in production and comprehension across all ages. The animacy modulation interacted with age in production but not in comprehension, suggesting age-related animacy differences in production but relatively stable differences in comprehension despite processing speed improvements. Importantly, these age-related production differences were also modulated by the BDS scores; only participants with higher BDS scores displayed age-related animacy differences. Together, these results indicate that comprehension and production develop at different rates and that the development of BDS performance interacts with age-dependent changes in sentence planning from late childhood to adolescence. More generally, the study highlights tasks' disparities to be explained by cognitive and developmental models of language.

Speech Perception in Noise Predicts Oral Narrative Comprehension in Children With Developmental Language Disorder

We examined the relative contribution of auditory processing abilities (tone perception and speech perception in noise) after controlling for short-term memory capacity and vocabulary, to narrative language comprehension in children with developmental language disorder. Two hundred and sixteen children with developmental language disorder, ages 6 to 9 years (Mean = 7; 6), were administered multiple measures. The dependent variable was children's score on the narrative comprehension scale of the Test of Narrative Language. Predictors were auditory processing abilities, phonological short-term memory capacity, and language (vocabulary) factors, with age, speech perception in quiet, and non-verbal IQ as covariates. Results showed that narrative comprehension was positively correlated with the majority of the predictors. Regression analysis suggested that speech perception in noise contributed uniquely to narrative comprehension in children with developmental language disorder, over and above all other predictors; however, tone perception tasks failed to explain unique variance. The relative importance of speech perception in noise over tone-perception measures for language comprehension reinforces the need for the assessment and management of listening in noise deficits and makes a compelling case for the functional implications of complex listening situations for children with developmental language disorder.

Cognitive Processes Related to Memory Capacity Explain Nearly All of the Variance in Language Test Performance in School-Age Children With and Without Developmental Language Disorder

The purpose of this study was to investigate the dimensionality of the cognitive processes related to memory capacity and language ability and to assess the magnitude of the relationships among these processes in children developing typically (TD) and children with developmental language disorder (DLD). Participants were 234 children between the ages of 7;0 and 11;11 (117 TD and 117 DLD) who were propensity matched on age, sex, mother education and family income. Latent variables created from cognitive processing tasks and standardized measures of comprehension and production of lexical and sentential aspects of language were tested with confirmatory factor analysis (CFA) and structural regression. A five-factor CFA model that included the constructs of Fluid Intelligence, Controlled Attention, Working Memory, Long-Term Memory for Language Knowledge and Language Ability yielded better fit statistics than two four-factor nested models. The four cognitive abilities accounted for more than 92% of the variance in the language measures. A structural regression model indicated that the relationship between working memory and language ability was significantly greater for the TD group than the DLD group. These results are consistent with a broad conceptualization of the nature of language impairment in older, school-age children as encompassing a dynamic system in which cognitive abilities account for nearly all of the variance in linguistic abilities.

An Evaluation of Expedited Transcription Methods for School-Age Children's Narrative Language: Automatic Speech Recognition and Real-Time Transcription

Purpose This study examined the accuracy and potential clinical utility of two expedited transcription methods for narrative language samples elicited from school-age children (7;5-11;10 [years;months]) with developmental language disorder. Transcription methods included real-time transcription produced by speech-language pathologists (SLPs) and trained transcribers (TTs) as well as Google Cloud Speech automatic speech recognition. Method The accuracy of each transcription method was evaluated against a gold-standard reference corpus. Clinical utility was examined by determining the reliability of scores calculated from the transcripts produced by each method on several language sample analysis (LSA) measures. Participants included seven certified SLPs and seven TTs. Each participant was asked to produce a set of six transcripts in real time, out of a total 42 language samples. The same 42 samples were transcribed using Google Cloud Speech. Transcription accuracy was evaluated through word error rate. Reliability of LSA scores was determined using correlation analysis. Results Results indicated that Google Cloud Speech was significantly more accurate than real-time transcription in transcribing narrative samples and was not impacted by speech rate of the narrator. In contrast, SLP and TT transcription accuracy decreased as a function of increasing speech rate. LSA metrics generated from Google Cloud Speech transcripts were also more reliably calculated. Conclusions Automatic speech recognition showed greater accuracy and clinical utility as an expedited transcription method than real-time transcription. Though there is room for improvement in the accuracy of speech recognition for the purpose of clinical transcription, it produced highly reliable scores on several commonly used LSA metrics. Supplemental Material https://doi.org/10.23641/asha.15167355.

Executive Function, Working Memory, and Verbal Fluency in Relation to Non-Verbal Intelligence in Greek-Speaking School-Age Children with Developmental Language Disorder

Developmental Language Disorder (DLD) is often associated with impairments in working memory (WM), executive functions (EF), and verbal fluency. Moreover, increasing evidence shows poorer performance of children with DLD on non-verbal intelligence tests relative to their typically developing (TD) peers. Yet, the degree and generality of relevant difficulties remain unclear. The present study aimed at investigating WM capacity, key EFs and verbal fluency in relation to non-verbal intelligence in Greek-speaking school-age children with DLD, compared to TD peers (8–9 years). To our knowledge, the present study is the first to attempt a systematic relevant assessment with Greek-speaking school-age children, complementing previous studies mostly involving English-speaking participants. The results showed that children with DLD scored lower than TD peers on the non-verbal intelligence measure. Groups did not differ in the inhibition measures obtained (tapping resistance to either distractor or proactive interference), but children with DLD were outperformed by TD peers in the WM capacity, updating, monitoring (mixing cost), and verbal fluency (phonological and semantic) measures. The effects showed limited (in the case of backward digit recall) or no dependence on non-verbal intelligence. Findings are discussed in terms of their theoretical and practical implications as well as in relation to future lines of research.

Speech production factors and verbal working memory in children and adults with developmental language disorder

Verbal working memory (VWM) deficits are common in individuals with developmental language disorder (DLD) but are not well understood. This study evaluated how both memory and language production factors influence VWM performance in children and adults with DLD, focusing on the influence of serial position, phonological activation (PA), and lexical frequency. Participants were 30 children with DLD and 26 with typical language (TL), and 21 adults with DLD and 23 with TL. The participants completed a listening span task in which they were asked to recall the final words of sentences in sets of increasing size. Responses (dependent variable) were coded as correct, incorrect, or no response. Final words were coded for frequency, serial position within the set, and PA (number of occurrences of the initial phoneme, vowel, and whole word in the task). These variables, along with age and language status, were entered as predictors in mixed-effects multinomial regression models. Extreme serial position, greater PA, and higher frequency reduced incorrect and no responses. These effects were attenuated for the DLD group, and the effect of greater PA varied with set size. The findings suggest that for individuals with DLD, VWM performance is affected by more limited effective language experience and by the dynamic task demands.

A New Memory Perspective on the Sentence Comprehension Deficits of School-Age Children With Developmental Language Disorder: Implications for Theory, Assessment, and Intervention

Purpose The nature of the relationship between memory and sentence comprehension in school-age children with developmental language disorder (DLD) has been unclear. We present a novel perspective that highlights the relational influences of fluid intelligence, controlled attention, working memory (WM), and long-term memory (LTM) on sentence comprehension in children with and without DLD. This perspective has new and important implications for theory, assessment, and intervention. Method We review a large-scale study of children with and without DLD that focused on the connections between cognition, memory, and sentence comprehension. We also summarize a new model of these relationships. Results Our new model suggests that WM serves as a conduit through which syntactic knowledge in LTM, controlled attention, and general pattern recognition indirectly influence sentence comprehension in both children with DLD and typically developing children. For typically developing children, language-based LTM and fluid intelligence indirectly influence sentence comprehension. However, for children with DLD, controlled attention plays a larger indirect role. Conclusions WM plays a key role in children's ability to apply their syntactic knowledge when comprehending canonical and noncanonical sentences. Our new model has important implications for the assessment of sentence comprehension and for the treatment of larger sentence comprehension deficits.

The Use of Structural Priming and Focused Recasts to Facilitate the Production of Subject- and Object-Focused Relative Clauses by School-Age Children With and Without Developmental Language Disorder

Purpose The purpose of this study was to examine the use of structural priming combined with a focused recasting procedure to elicit subject- and object-focused, center-embedded relative clauses from students with developmental language disorders (DLDs) and typically developing (TD) students. Method A total of 26 children (13 DLD, 13 TD), ranging in age from 6;10 to 10;11 (years;months), participated in this study. All children completed a priming and recasting task that targeted subject- and object-focused relatives. The stimuli were presented in two blocks, which each contained 40 trials for each sentence type. Results Children with DLD and their TD peers were significantly more accurate producing subject-focused than object-focused relatives. An analysis of rate of learning indicated that significantly more trials were required for subjects in the DLD group to demonstrate consistent performance on both subject- and object-focused relatives. Conclusions The study supports the feasibility of combining an implicit priming task with an explicit recasting task for teaching subject-focused relative clauses to children with DLD. However, it is likely that additional instruction and/or more trials will be necessary for children with DLD to attain consistent performance levels. Supplemental Material https://doi.org/10.23641/asha.12670847.

Tracking Changes in Frontal Lobe Hemodynamic Response in Individual Adults With Developmental Language Disorder Following HD tDCS Enhanced Phonological Working Memory Training: An fNIRS Feasibility Study

Background: Current research suggests a neurobiological marker of developmental language disorder (DLD) in adolescents and young adults may be an atypical neural profile coupled with behavioral performance that overlaps with that of normal controls. Although many imaging techniques are not suitable for the study of speech and language processing in DLD populations, fNIRS may be a viable option. In this study we asked if fNIRS can be used to identify atypical cortical activation patterns in individual adults with DLD and track potential changes in cortical activation patterns following a phonological working memory training protocol enhanced with anodal HD tDCS stimulation to the presupplementary motor area (preSMA).

Objective/Hypothesis: The purpose of this study was two-fold: (1) to determine if fNIRS can be used to identify atypical hemodynamic responses in individual young adults with DLD during active spoken word processing and, (2) to determine if fNIRS can detect changes in hemodynamic response in these same adults with DLD following anodal HD tDCS enhanced phonological working memory training.

Methods: Two adult subjects with DLD (female, age 25) completed a total of two sessions of fNIRs working memory task prior to and following one session of a non-word repetition task paired with anodal HD tDCS (1.0 mA tDCS; 20 min) to the preSMA. Standardized z-scores of behavioral measures (accuracy and reaction time) and changes in hemodynamic response during an n-back working memory task for the two participants with DLD was compared to that of a normative sample of 21 age- and gender- matched normal controls (ages 18 to 25) prior to and following phonological working memory training.

Results: Individual standardized z-scores for each participant with DLD indicated that prior to training, hemoglobin response in the prefrontal lobe for both participants was markedly different from each other and normal controls. Following training, standard scores showed that the hemodynamic response for both participants moved within normal limits for ROIs.

Conclusion: These findings highlight the feasibility of fNIRS to establish individual differences in the link between behavior and neural patterns in single subjects with DLD, as well as track individual differences in changes in brain activity following working memory training.

Diagnosis of Developmental Language Disorder in Research Studies

Purpose The aim of this study was to investigate the extent to which researchers in the field of developmental language disorder are utilizing validated methods to diagnose their research participants. Method We examined 90 research articles published from 2015 to 2019 that included English-speaking participants from the United States who were identified as having a developmental language disorder or specific language impairment. From these articles, we identified the tests and measures used to identify participants and classify them as healthy or impaired. We then consulted the test manuals and the literature to find information on sensitivity and specificity of the test and the evidence-based cut score that maximized identification accuracy. Results Of the 90 articles examined, 38 (42%) were found to reflect validated diagnostic methods, and 51 (58%) did not. Conclusion Our results illustrate that validated methods are used less than half of the time even by those who should have a high level of expertise and despite calls for increasing scientific rigor in research practices.

Relationship between working memory and complex syntax in children with Developmental Language Disorder

Some theories of Developmental Language Disorder (DLD) explain the linguistic deficits observed in terms of limitations in non-linguistic cognitive systems such as working memory. The goal of this research is to clarify the relationship between working memory and the processing of complex sentences by exploring the performance of 28 French-speaking children with DLD aged five to fourteen years and 48 typically developing children of the same age in memory and linguistic tasks. We identified predictive relationships between working memory and the comprehension and repetition of complex sentences in both groups. As for syntactic measures in spontaneous language, it is the complex spans that explain the major part of the variance in the control children. In children with DLD, however, simple spans are predictive of these syntactic measures. Our results thus reveal a robust relationship between working memory and syntactic complexity, with clinical implications for the treatment of children with DLD.

Explicit Grammatical Intervention for Developmental Language Disorder: Three Approaches

Purpose This article summarizes the shared principles and evidence underpinning methods employed in the three sentence-level (syntactic) grammatical intervention approaches developed by the authors. We discuss associated clinical resources and map a way forward for clinically useful research in this area. Method We provide an overview of the principles and perspectives that are common across our three syntactic intervention approaches: MetaTaal (Zwitserlood, 2015; Zwitserlood, Wijnen, et al., 2015), the SHAPE CODING system (Ebbels, 2007; Ebbels et al., 2014, 2007), and Complex Sentence Intervention (Balthazar & Scott, 2017, 2018). A description of each approach provides examples and summarizes current evidence supporting effectiveness for children with developmental language disorder ranging in age from 5 to 16 years. We suggest promising directions for future research that will advance our understanding of effective practices and support more widespread adoption of syntactic interventions with school-age children. Conclusion In each approach to syntactic intervention, careful and detailed analysis of grammatical knowledge is used to support target selection. Intervention targets are explicitly described and presented systematically using multimodal representations within engaging and functional activities. Treatment stimuli are varied within a target pattern in order to maximize learning. Similar intervention intervals and intensities have been studied and proven clinically feasible and have produced measurable effects. We identify a need for more research evidence to maximize the effectiveness of our grammatical interventions, encompassing languages other than English, as well as practical clinical tools to guide target selection, measurement of outcomes, and decisions about how to tailor interventions to individual needs.

A Comparison of the Storage-Only Deficit and Joint Mechanism Deficit Hypotheses of the Verbal Working Memory Storage Capacity Limitation of Children With Developmental Language Disorder

Purpose The storage-only deficit and joint mechanism deficit hypotheses are 2 possible explanations of the verbal working memory (vWM) storage capacity limitation of school-age children with developmental language disorder (DLD). We assessed the merits of each hypothesis in a large group of children with DLD and a group of same-age typically developing (TD) children. Method Participants were 117 children with DLD and 117 propensity-matched TD children 7-11 years of age. Children completed tasks indexing vWM capacity, verbal short-term storage, sustained attention, attention switching, and lexical long-term memory (LTM). Results For the DLD group, all of the mechanisms jointly explained 26.5% of total variance. Storage accounted for the greatest portion (13.7%), followed by controlled attention (primarily sustained attention; 6.5%) and then lexical LTM (5.6%). For the TD group, all 3 mechanisms together explained 43.9% of total variance. Storage accounted for the most variance (19.6%), followed by lexical LTM (16.0%), sustained attention (5.4%), and attention switching (3.0%). There was a significant LTM × Group interaction, in which stronger LTM scores were associated with significantly higher vWM capacity scores for the TD group as compared to the DLD group. Conclusions Results support a joint mechanism deficit account of the vWM capacity limitation of children with DLD. Results provide substantively new insights into the underlying factors of the vWM capacity limitation in DLD. Supplemental Material https://doi.org/10.23641/asha.9932312.