Do Children With Developmental Language Disorder (DLD) Have Difficulties With Interference Control, Visuospatial Working Memory, and Selective Attention? Developmental Patterns and the Role of Severity and Persistence of DLD

Using semantic verbal fluency to estimate the relative and absolute vocabulary size of bilinguals: An exploratory study of children and adolescents

INTRODUCTION

The full assessment of bilingual children often involves at least one language for which formal vocabulary tests are lacking and which the examiner does not speak. We examined, in a sample of children with typical development (TD), whether a semantic verbal fluency task, typically used in research as a measure of executive function, could be used in the place of a formal vocabulary test to estimate vocabulary knowledge when formal tests are not available.

METHOD

113 TD monolingual French speakers and TD bilinguals and with varying degrees of exposure to French, age 6 to 17 years, completed tests of vocabulary knowledge and semantic verbal fluency. A subset of 64 participants spoke French and English and were tested in both languages. Verbal fluency measures calculated using a traditional method which uses specific rules for superordinate categories and for animals of different sex and age and a simplified scoring method which simply counts all words produced, included the total number of words produced in each language, Total Vocabulary and Conceptual Vocabulary measures combining both languages, as well as analyses of lexical composition and word frequency within the study sample.

RESULTS

Linear regressions revealed that the number of words produced predicted vocabulary size in a language-specific way, with slightly stronger predictions made by the simplified scoring method. As expected, bilinguals produced more words and more unique words in their language of greater exposure, while different exposure groups were equivalent in measures combining both languages, including their Total vocabulary and Conceptual vocabulary. Producing unusual words (infrequently produced in the study sample) indicated higher vocabulary scores.

CONCLUSIONS

This study supports the use of the verbal fluency task as a quick and simple tool to obtain a rough estimate of vocabulary size in TD monolinguals and bilinguals. This tool shows promise as well in clinical work with other populations, subject to further verification.

Evaluating the role of word-related parameters in the discriminative power of a novel nonword repetition task for bilingual children

In bi- and monolingual children, nonword repetition tasks (NWRTs) differentiate typically developing (TD) children from children with Developmental Language Disorder (DLD) or children with a risk of DLD. Previous research has highlighted the importance of considering language specificity in nonword (NW) construction especially for bilingual children. A novel NWRT has been designed for the screening of DLD risk in the bilingual Italian-German preschool population, creating lists of language-specific (for the two target languages) and language-non-specific NWs. This study aimed to test the discriminative validity of this NWRT and to identify the characteristics of the NWs that maximise discriminative validity within language-specific and language-non-specific subsets. The findings confirm the role of language specificity (in terms of target language alikeness) but also of other characteristics related to word structure complexity.

A systematic review of factors that impact reading comprehension in children with developmental language disorders

Children with developmental language disorder (DLD) have a high rate of co-occurring reading difficulties. The current study aims to (i) examine which factors within the Active View of Reading (AVR; Duke & Cartwright, 2021) apply to individuals with DLD and (ii) investigate other possible factors that relate to reading comprehension ability in individuals with DLD, outside the components in the AVR. Electronic database search and journal hand-search yielded 5058 studies published before March 2022 related to reading comprehension in children with DLD. 4802 articles were excluded during abstract screening, yielding 256 studies eligible for full-text review. Following full-text review, 44 studies were included and further coded for demographics, language of assessment, description of reported disabilities, behavioral assessment, and reading comprehension assessment. While the results aligned with the AVR model, three additional factors were identified as significantly relating to reading comprehension abilities in children with DLD: expressive language (oral and written), question types of reading assessment, and language disorder history. Specifically, expressive language was positively associated with reading comprehension ability, while resolved DLD showed higher reading comprehension abilities than persistent DLD. Furthermore, children with DLD may face additional difficulties in comprehending inference-based questions. This study provides factors for researchers, educators, and clinical professionals to consider when evaluating the reading comprehension of individuals with DLD. Future research should further explore the relative importance of factors of the AVR to reading comprehension outcomes throughout development.

Acquisition of Mandarin long passives by children with developmental language disorder

This study investigated the comprehension and production of long passives (i.e. bei-constructions with an overt agent) in Mandarin-speaking children with developmental language disorder (DLD). Seventeen preschool children with DLD (1 female; mean age: 61 months old) and 23 typically developing (TD) children (6 females; mean age: 62 months old) participated in a sentence-picture matching task (for comprehension) and an elicited production task. Their nonverbal working memory (NVWM) was measured with the fourth edition of the Wechsler Preschool and Primary Scale of Intelligence. Results showed that children with DLD were less accurate and more likely to choose the picture with reversed thematic roles than their TD peers on passives in the sentence-picture matching task; in the elicited production task, they produced fewer target responses than TD children in passives. For NVWM, although that of the DLD group was lower than that of TD children, most children in the DLD group were within the average range. Furthermore, their performance on passives in the comprehension and production tasks was significantly correlated with their NVWM, which adds to the body of work suggesting links between complex syntax and working memory. However, the fact that NVWM could be preserved in the face of difficulties with passives suggests that this link may be due to NVWM enhancing performance during tasks with a high visual component, while it may not be underlyingly responsible for syntactic impairments in children with DLD.

Age of onset, motivation, and anxiety as predictors of grammar and vocabulary outcomes in English as a foreign language learners with developmental language disorder

INTRODUCTION

Like children with typical language development, their peers with developmental language disorder (DLD) are expected to learn English as a foreign language (EFL). For pupils without DLD, it is well-established that amount of informal exposure to English outside of the classroom, starting age of EFL instruction and motivation are strong positive predictors of EFL learning rate and/or achievement, whereas anxiety is negatively related to performance. This paper is the first attempt to investigate how these predictors of EFL performance operate in learners with DLD.

METHODS

Participants were nineteen Dutch-speaking 7th graders with DLD learning English as a school subject at a specialist education facility in the Netherlands. English receptive grammar and receptive vocabulary were measured twice, with a four-month interval. Foreign language learning motivation, anxiety and (length and amount of) informal exposure to and instruction in English were measured via questionnaires.

RESULTS

The participants did not show any progress on English vocabulary and grammar. At Time 1, vocabulary and grammar scores were positively related to starting age of EFL instruction and negatively related to anxiety. For vocabulary, achievement was also positively predicted by attitudes towards English lessons. Only the relationship between starting age of instruction and vocabulary outcomes was visible at Time 2. Amount and length of informal exposure to English did not predict performance, which is in stark contrast to the patterns observed in EFL learners with typical language development.

CONCLUSIONS

We conclude that children with DLD benefit from a later onset of foreign language lessons, whereas length and amount of out-of-school exposure to English are less important in the context of DLD, possibly due to difficulty with implicit learning.

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.

Cognitive processes associated with working memory in children with developmental language disorder

The current study examined how individual differences in language, nonverbal, and attention abilities relate to working memory in children with developmental language disorder (DLD) relative to age-matched typically developing (TD) peers using an interference-based model of working memory as our theoretical framework. Our experimental paradigm involved varying the domain (verbal/nonverbal) of recall items and an interference processing task, testing effects of interference. We examined the relative importance of language, nonverbal, and attention skills in predicting working memory performance by using Bayesian leave-one-out cross-validation to compare models with varied combinations of these skills as predictors. We then statistically tested selected models. Selected models were similar between groups for nonverbal, but not verbal, working memory. Language, nonverbal, and attention skills were associated with performance regardless of whether the working memory task was verbal or nonverbal for the DLD group, yet only attention was associated with verbal working memory for the TD group. A broader set of cognitive processes was involved in verbal recall in children with DLD than in TD peers, potentially reflecting diminished specialization of cognitive processes underlying language. The interference-based model of working memory accounted for interrelationships among language, processing speed, and inhibition of interference, revealing new insights into verbal processing.

Between Shifting and Feedback Processing in the Wisconsin Card Sorting Test in Children with Developmental Language Disorder

Children with developmental language disorder (DLD) demonstrate deficits in executive functioning; however, the specific components of executive functioning that are affected in this population are not well understood. This study evaluated set shifting and feedback processing in a Wisconsin Card Sorting Test (WCST) performed by 24 children with and without DLD. The behavioral results revealed poorer performance by the DLD group in measures of accuracy, proportion of correct rule shifts, perseverative errors on shift trials, and proportion of effective responses to feedback. Electrophysiological measures (event-related potentials, or ERPs) indicated different patterns of response to negative feedback that signaled the need for rule shifting, with the DLD group showing a trend toward processing shift cues as negative feedback. Group differences were found in the processing of the first and last positive feedback, with overall stronger responses to positive feedback by children with DLD. However, both groups showed a similar pattern of diminished attention to positive feedback when rule learning was established. Taken together, children with DLD demonstrated the inefficient processing of negative feedback in the context of rule-shifting and difficulty in establishing and maintaining a rule.

Towards a Characterization of Late Talkers: The Developmental Profile of Children with Late Language Emergence through a Web-Based Communicative-Language Assessment

Children acquire language naturally, but there is variation in language acquisition patterns. Indeed, different internal and external variables play a role in acquiring language. However, there are open research questions about the contribution of different variables to language development. Moreover, with societal changes and due to the pandemic situation, there has been a growing interest in testing digitalization related to indirect language acquisition assessment. In this study, a web-based assessment survey was developed to (1) describe the relation between expressive vocabulary, Socio-Conversational Skills (SCS), gender, parental education, executive functions (EFs), and pretend play; (2) determine whether the survey can detect differences between late talkers (LTs) and children with typical language development; (3) identify children with "overall high" and "overall low" communicative-language scores to test the validity of expressive vocabulary as a main indicator to detect LTs. The parents of 108 Italian children (51 males) aged 24-36 months participated in the study. The results showed that expressive vocabulary correlates with measures of SCS (assertiveness and responsiveness) and is reliable in identifying LTs (d = 2.73). Furthermore, SCS and EFs contribute to better characterizing the developmental profile of children aged 24-36 months.

Attentional modulation of interhemispheric (a)symmetry in children with developmental language disorder

The nature of auditory processing problems in children with developmental language disorder (DLD) is still poorly understood. Much research has been devoted to determining the extent to which DLD is associated with general auditory versus language-specific dysfunction. However, less emphasis has been given to the role of different task conditions in these dysfunctions. We explored whether children with DLD demonstrate atypical interhemispheric asymmetry during the auditory processing of speech and non-speech sounds and whether this interhemispheric balance is modulated by attention. Magnetoencephalography was used to record auditory evoked fields in 18 children (9 to 10 years old), 9 with DLD and 9 with language typical development, during active or passive listening to speech and non-speech sounds. A linear mixed model analysis revealed a bilateral effect of attention in both groups. Participants with DLD demonstrated atypical interhemispheric asymmetry, specifically in the later (185-600 ms) time window but only during the passive listening condition. During the active task, the DLD group did not differ from the typically developed children in terms of hemispheric balance of activation. Our results support the idea of an altered interhemispheric balance in passive auditory response properties in DLD. We further suggest that an active task condition, or top-down attention, can help to regain leftward lateralization, particularly in a later stage of activation. Our study highlights the highly dynamic and interhemispheric nature of auditory processing, which may contribute to the variability in reports of auditory language processing deficits in DLD.

Are items actively removed from working memory during free time in children with developmental language disorder?

BACKGROUND

Children with developmental language disorder (DLD) have deficits in verbal and non-verbal processing relative to typically developing (TD) peers, potentially reflecting difficulties in working memory, processing speed and inhibition of interference. We examined working memory in children with DLD using the serial-order-in-a-box-complex span (SOB-CS) interference-based model, which posits a time-based mechanism, free time, that governs how interference affects processing performance.

AIMS

(1) To determine the degree to which children with DLD and TD children differ in the amount of free time available during working memory tasks, and whether potential group differences in free time differ depending on the domain of task demands? (2) To determine the relationship between free time and interference effects on working memory accuracy in children with DLD relative to TD peers.

METHODS & PROCEDURES

We examined the relationship between free time and working memory in children aged 9-13 years with DLD relative to age-matched TD peers. Working memory tasks involved five conditions that varied verbal versus non-verbal task demands in an interference processing phase relative to a recall test phase. Free time was the time between response on the interference processing task and onset of the recall test phase.

OUTCOMES & RESULTS

DLD and TD groups did not differ in total free time in any condition. Results indicated group differences in the relationship between free time and accuracy in the conditions involving verbal recall, but not non-verbal recall. In the verbal-only condition, relatively more free time was associated with worse accuracy for the DLD group, but with better accuracy for the TD group. In the condition with verbal recall paired with non-verbal interference processing, relatively more free time was associated with better accuracy for the DLD group, but not for the TD group.

CONCLUSIONS & IMPLICATIONS

The overall findings suggest that free time between cognitive operations is positively associated with working memory for both verbal and non-verbal recall, except in the presence of high verbal interference for the DLD group (i.e., verbal interference paired with verbal recall). This finding may reflect poor encoding and attention under particularly challenging verbal processing demands for the DLD group. This study also demonstrates the importance of considering the interrelationships between processing speed and interference in working memory performance.

WHAT THIS PAPER ADDS

What is already known on the subject DLD is characterized by core deficits in verbal processing, but also deficits in non-verbal processing. Processing-based hypotheses of DLD-limited verbal working memory, slowed processing speed and inefficient inhibition-do not fully account for behavioural profiles in DLD when considered separately, yet there is evidence suggesting interrelationships among these factors. What this paper adds to existing knowledge The current study tests the key mechanism posited by a theoretical framework that has the potential to integrate these processing-based hypotheses. Our findings indicate that the effect of this mechanism differed in DLD relative to TD peers in the presence of high verbal task demands. Our findings also demonstrate the importance of considering the interrelationships among cognitive processes in children with DLD. What are the potential or actual clinical implications of this work? In practice, results from the current study suggest that children with DLD may benefit from supplementing verbal information with non-verbal information and from pauses between successive presentations of verbal information. These strategies may support their ability to maintain and act on information during verbal processing.

Working Memory Performance in Children With Developmental Language Disorder: The Role of Domain

PURPOSE

This study examined working memory in children with developmental language disorder (DLD). The overarching goal of this work was to integrate three primary processing-based hypotheses of DLD, (a) limited verbal working memory, (b) slowed processing speed, and (c) inefficient inhibition of interference, by using the serial-order-in-a-box-complex span (SOB-CS) computational model as our theoretical framework. We also examined the role of domain in working memory performance by varying the domain of interference and recall (i.e., verbal vs. nonverbal) task demands.

METHOD

Participants were 55 school-age children, 21 children with DLD and 34 age-matched typically developing (TD) peers (9-13 years old).

RESULTS

Findings indicated that verbal and nonverbal working memory performance was poorer in the DLD than TD group. There was a modest benefit of dispersing interference and recall task demands across domains relative to task demands being within one domain, yet verbal interference affected performance to a greater degree than nonverbal interference in the DLD group.

CONCLUSIONS

Overall findings supported a role for each of the processing-based hypotheses of DLD, albeit an incomplete role. In contrast, the SOB-CS model accounted for interrelationships among these processing-based factors and provided an explanation across patterns of findings. Thus, the SOB-CS model represents a useful step forward in explaining processing in children with DLD.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19526179.

Do Children With Developmental Language Disorder Activate Scene Knowledge to Guide Visual Attention? Effect of Object-Scene Inconsistencies on Gaze Allocation

Our visual environment is highly predictable in terms of where and in which locations objects can be found. Based on visual experience, children extract rules about visual scene configurations, allowing them to generate scene knowledge. Similarly, children extract the linguistic rules from relatively predictable linguistic contexts. It has been proposed that the capacity of extracting rules from both domains might share some underlying cognitive mechanisms. In the present study, we investigated the link between language and scene knowledge development. To do so, we assessed whether preschool children (age range = 5;4–6;6) with Developmental Language Disorder (DLD), who present several difficulties in the linguistic domain, are equally attracted to object-scene inconsistencies in a visual free-viewing task in comparison with age-matched children with Typical Language Development (TLD). All children explored visual scenes containing semantic (e.g., soap on a breakfast table), syntactic (e.g., bread on the chair back), or both inconsistencies (e.g., soap on the chair back). Since scene knowledge interacts with image properties (i.e., saliency) to guide gaze allocation during visual exploration from the early stages of development, we also included the objects’ saliency rank in the analysis. The results showed that children with DLD were less attracted to semantic and syntactic inconsistencies than children with TLD. In addition, saliency modulated syntactic effect only in the group of children with TLD. Our findings indicate that children with DLD do not activate scene knowledge to guide visual attention as efficiently as children with TLD, especially at the syntactic level, suggesting a link between scene knowledge and language development.

Reading outcomes in children with developmental language disorder: A person-centered approach

BACKGROUND AND AIMS

Many children with Developmental Language Disorder (DLD) develop reading difficulties. The purpose of this study is to better understand variation in the reading outcomes of children with DLD using a person-centered approach.

METHOD

87 monolingual Dutch children diagnosed with DLD performed at ages 5 or 6 years nine tests of nonverbal IQ, oral language proficiency, phonological memory (PM) and executive functioning (EF). Two years later, the same children were tested on single (non-)word reading. Latent profile analyses were conducted to identify profiles based on oral language proficiency, phonological memory and executive functioning at age 5-6 years, which, in turn, were related to nonverbal IQ and to single-word reading two years later.

RESULTS

Four profiles were identified and labelled relative to their position within the DLD-sample: 1. Weak performance overall, 2. Strong EF-average language and PM, 3. Mild working memory (WM) deficiencies-average language and PM, 4. Strong development overall. Profiles 1 and 3 had below average nonverbal IQ scores and were associated with low word reading outcomes two years later.

CONCLUSIONS

Within the group of children with DLD, children with relatively weak oral language, phonological memory and executive functioning, or children with working memory deficiencies are most at risk for developing reading difficulties. The findings support a multiple risk framework and confirm that a person-centered approach is promising in predicting reading outcomes in DLD.Implications: Research into individual differences in DLD is dominated by variable-centered approaches. This study illustrates how a person-centered approach, which views variables as properties of individuals, captures variation in the DLD-population. Using this bottom-up approach, the study highlights how an individual's strengths and weaknesses across different developmental domains can be combined into profiles that relate to later reading outcomes. As such, it can provide an example for future DLD research.