Nonverbal Switching Ability of Monolingual and Bilingual Children with and without Developmental Language Disorder

Bilingualism is associated with enhanced switching skills, while a developmental language disorder (DLD) may negatively impact switching ability. However, both studies with bilinguals as well as studies including children with DLD have revealed mixed results. Moreover, the interaction of bilingualism and DLD has not been addressed and the origin of the stronger or weaker switching performance is unknown. The current study aimed to fill these gaps. Monolingual and bilingual children with and without DLD (n = 32 in each of the four groups) completed a nonverbal color/shape switching task when they were 7 to 8 years old, and a Continuous Performance Task two years earlier. The latter tapped into their response inhibition and sustained attention skills, which may underlie switching ability. No differences between monolinguals and bilinguals were found on the switching task. Children with DLD had higher mixing costs than peers without DLD, which was driven by differences in sustained attention skills. These results add to the body of research indicating that the cognitive advantages of bilingualism are unstable. Additionally, the results substantiate the hypothesis that attention processes are foundational for complex cognitive skills, such as switching, and suggest cascading effects for children with weaker attention skills, such as children with DLD

Cognitive flexibility in children with Developmental Language Disorder: Drawing of nonexistent objects

Cognitive flexibility is the ability to adapt thoughts and behaviors to new environments. Previous studies investigating cognitive flexibility in children with Developmental Language Disorder (DLD) present contradictory findings. In the current study, cognitive flexibility was assessed in 5- and 6-year-old preschoolers with DLD (n = 23) and peers with typical development (TD; n = 50) using a nonexistent object drawing (NEOD) task. The children were asked to draw a nonexistent man and a nonexistent house. The children with DLD did not differ from their peers with TD on simple category changes, which were comprised of changes in the size or shape of parts of the object, change of the whole shape of the object, and deletion of parts of the object. Nevertheless, children with DLD made fewer more complex, high-level category changes, which included samecategory insertions, position exchange of object’s parts, and cross-category insertions. The difference between DLD and TD on high-level category changes was related to differences between the two groups in verbal short-term memory and inhibition. Furthermore, children with DLD made no changes to their original drawings of an existing man and house more often than their peers with TD. It is concluded that children with DLD aged 5–6 years show less flexibility on the NEOD task than age-matched children with TD. This difference in cognitive flexibility may be related to lower levels of verbal short-term memory and inhibition ability of children with DLD, or to different use of these cognitive skills on the NEOD task

Understanding variation in prospective poor decoders: A person-centred approach from kindergarten to Grade 2

In the present study, we aimed to clarify variation in prospective poor decoders by studying the development of their word decoding skills during the first 1½ years of formal reading education and their unique pre-reading profiles before the onset of formal reading education. Using structural equation modelling and a factorial mixed model analysis of variance (ANOVA), we found autoregression and growth in the word decoding efficiency of prospective poor decoders (n = 90) and matched prospective adequate decoders (n = 90) in first and second grade. However, the gap between the two groups widened over time. Next, we zoomed in on the group of poor decoders by retrospectively studying their individual variation regarding cognitive and linguistic pre-reading skills. Using latent profile analysis, we found three distinct pre-reading profiles: (1) Poor PA, Letter Knowledge, RAN, and Verbal STM; (2) Poor PA and Letter Knowledge; and (3) Poor RAN. Together, these findings suggest that reading difficulties emerge at the intersection of multiple risk factors which can be detected in kindergarten, and that these reading problems persist throughout early reading education

Interdependence between L1 and L2: the case of Syrian children with refugee backgrounds in Canada and the Netherlands

Children who are refugees become bilingual in circumstances that are often challenging and that can vary across national contexts. We investigated the second language (L2) syntactic skills of Syrian children aged 6-12 living in Canada (n = 56) and the Netherlands (n = 47). Our goal was to establish the impact of the first language (L1 = Syrian Arabic) skills on L2 (English, Dutch) outcomes and whether L1–L2 interdependence is influenced by the length of L2 exposure. To measure L1 and L2 syntactic skills, cross-linguistic Litmus Sentence Repetition Tasks (Litmus-SRTs) were used. Results showed evidence of L1–L2 interdependence, but interdependence may only surface after sufficient L2 exposure. Maternal education level and refugee camp experiences differed between the two samples. Both variables impacted L2 outcomes in the Canadian but not in the Dutch sample, demonstrating the importance to examine refugee children’s bilingual language development in different national contexts

What risk factors for Developmental Language Disorder can tell us about the neurobiological mechanisms of language development

Language is a complex multidimensional cognitive system that is connected to many neurocognitive capacities. The development of language is therefore strongly intertwined with the development of these capacities and their neurobiological substrates. Consequently, language problems, for example those of children with Developmental Language Disorder (DLD), are explained by a variety of etiological pathways and each of these pathways will be associated with specific risk factors. In this review, we attempt to link previously described factors that may interfere with language development to putative underlying neurobiological mechanisms of language development, hoping to uncover openings for future therapeutical approaches or interventions that can help children to optimally develop their language skills

Word reading in monolingual and bilingual children with developmental language disorder

Many children with developmental language disorder (DLD) are reported to have word reading difficulties. However, previous research has focused mostly on monolingual children. The present study used two existing datasets to assess word reading outcomes of bilingual children with DLD. In Study 1, we compared word reading outcomes of monolingual and bilingual children with and without DLD (n = 93 monolingual DLD; n = 33 bilingual DLD, n = 42 monolingual TD; n = 74 bilingual TD). In Study 2, we compared those of monolingual (n = 91) and bilingual children with DLD (n = 51) on the basis of school record data. Findings from both studies show mean poor word reading outcomes and a high incidence of poor readers in the groups of children with DLD. Despite lower oral language outcomes of bilingual children in the mainstream language, reading outcomes of monolingual and bilingual children (with/without DLD) did not differ or outcomes were even better for the bilingual children. Overall, these findings indicate that DLD is a risk factor for word reading difficulties, while bilingualism is not

Robustness of the rule-learning effect in 7-month-old infants: A close, multicenter replication of Marcus et al. (1999)

We conducted a close replication of the seminal work by Marcus and colleagues from 1999, which showed that after a brief auditory exposure phase, 7-month-old infants were able to learn and generalize a rule to novel syllables not previously present in the exposure phase. This work became the foundation for the theoretical framework by which we assume that infants are able to learn abstract representations and generalize linguistic rules. While some extensions on the original work have shown evidence of rule learning, the outcomes are mixed, and an exact replication of Marcus et al.'s study has thus far not been reported. A recent meta-analysis by Rabagliati and colleagues brings to light that the rule-learning effect depends on stimulus type (e.g., meaningfulness, speech vs. nonspeech) and is not as robust as often assumed. In light of the theoretical importance of the issue at stake, it is appropriate and necessary to assess the replicability and robustness of Marcus et al.'s findings. Here we have undertaken a replication across four labs with a large sample of 7-month-old infants (N = 96), using the same exposure patterns (ABA and ABB), methodology (Headturn Preference Paradigm), and original stimuli. As in the original study, we tested the hypothesis that infants are able to learn abstract “algebraic” rules and apply them to novel input. Our results did not replicate the original findings: infants showed no difference in looking time between test patterns consistent or inconsistent with the familiarization pattern they were exposed to

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 personcentered 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. <p<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

Regular and irregular inflection in different groups of bilingual children and the role of verbal short-term and verbal working memory

Bilingual children often experience difficulties with inflectional morphology. The aim of this longitudinal study was to investigate how regularity of inflection in combination with verbal short-term and working memory (VSTM, VWM) influences bilingual children’s performance. Data from 231 typically developing five- to eight-year-old children were analyzed: Dutch monolingual children (N = 45), Frisian-Dutch bilingual children (N = 106), Turkish-Dutch bilingual children (N = 31), Tarifit-Dutch bilingual children (N = 38) and Arabic-Dutch bilingual children (N = 11). Inflection was measured with an expressive morphology task. VSTM and VWM were measured with a Forward and Backward Digit Span task, respectively. The results showed that, overall, children performed more accurately at regular than irregular forms, with the smallest gap between regulars and irregulars for monolinguals. Furthermore, this gap was smaller for older children and children who scored better on a non-verbal intelligence measure. In bilingual children, higher accuracy at using (irregular) inflection was predicted by a smaller cross-linguistic distance, a larger amount of Dutch at home, and a higher level of parental education. Finally, children with better VSTM, but not VWM, were more accurate at using regular and irregular inflectio

No Bilingual Benefits Despite Relations Between Language Switching and Task Switching

Previous research has shown that bilingual children outperform monolinguals on tasks testing cognitive control. Bilinguals’ enhanced cognitive control is thought to be caused by the necessity to exert more language control in bilingual compared to monolingual settings. Surprisingly, between-group research of cognitive effects of bilingualism is hardly ever combined with within-group research that investigates relationships between language control and cognitive control. The present study compared 27 monolingual Dutch and 27 bilingual Turkish-Dutch children matched on age and fluid intelligence on their performance in a nonverbal switching task. Within the group of bilinguals, the relationship between nonverbal switching and language switching was examined. The results revealed no between-group differences on nonverbal switching. Within the bilingual sample, response times in the language switching and nonverbal switching tasks were related, although no relationships were found between accuracy, switching cost and mixing cost on both tasks. The results support the hypothesis that children utilize domain-general cognitive control in language switching, but this relationship does not entail that bilinguals have better cognitive control than monolinguals