Purpose This study evaluated a newly developed quasi-universal nonword repetition task (Q-U NWRT) as a diagnostic tool for bilingual children with language impairment (LI) who have Dutch as a 2nd language. The Q-U NWRT was designed to be minimally influenced by knowledge of 1 specific language in contrast to a language-specific NWRT with which it was compared. Method One hundred twenty monolingual and bilingual children with and without LI participated (30 per group). A mixed-design analysis of variance was used to investigate the effects of LI and bilingualism on the NWRTs. Receiver operating characteristic analyses were conducted to evaluate the instruments' diagnostic value. Results Large negative effects of LI were found on both NWRTs, whereas negative effects of bilingualism only occurred on the language-specific NWRT. Both instruments had high clinical accuracy in the monolingual group, but only the Q-U NWRT had high clinical accuracy in the bilingual group. Conclusions This study indicates that the Q-U NWRT is a promising diagnostic tool to help identify LI in bilingual children learning Dutch as a 2nd language. The instrument was clinically accurate in both a monolingual and bilingual group of children and seems better able to disentangle LI from language disadvantage than more language-specific measures.

Purpose: Many children with developmental language disorder (DLD) have weaknesses in executive functioning (EF), specifically in tasks testing interference control and working memory. It is unknown how EF develops in children with DLD, if EF abilities are related to DLD severity and persistence, and if EF weaknesses expand to selective attention. This study aimed to address these gaps. Method: Data from 78 children with DLD and 39 typically developing (TD) children were collected at three times with 1-year intervals. At Time 1, the children were 5 or 6 years old. Flanker, Dot Matrix, and Sky Search tasks tested interference control, visuospatial working memory, and selective attention, respectively. DLD severity was based on children's language ability. DLD persistence was based on stability of the DLD diagnosis. Results: Performance on all tasks improved in both groups. TD children outperformed children with DLD on interference control. No differences were found for visuospatial working memory and selective attention. An interference control gap between the DLD and TD groups emerged between Time 1 and Time 2. Severity and persistence of DLD were related to interference control and working memory; the impact on working memory was stronger. Selective attention was unrelated to DLD severity and persistence. Conclusions: Age and DLD severity and persistence determine whether or not children with DLD show EF weaknesses. Interference control is most clearly impaired in children with DLD who are 6 years and older. Visuospatial working memory is impaired in children with severe and persistent DLD. Selective attention is spared.

Background. The language profiles of children with language impairment (LI) and bilingual children can show partial, and possibly temporary, overlap. The current study examined the persistence of this overlap over time. Furthermore, we aimed to better understand why the language profiles of these two groups show resemblance, testing the hypothesis that the language difficulties of children with LI reflect a weakened ability to maintain attention to the stream of linguistic information. Consequent incomplete processing of language input may lead to delays that are similar to those originating from reductions in input frequency. Methods. Monolingual and bilingual children with and without LI (N=128), aged 5 to 8 years old, participated in this study. Dutch receptive vocabulary and grammatical morphology were assessed at three waves. In addition, auditory and visual sustained attention were tested at wave 1. Mediation analyses were performed to examine relationships between LI, sustained attention, and language skills. Results. Children with LI and bilingual children were outperformed by their typically developing (TD) and monolingual peers, respectively, on vocabulary and morphology at all three waves. The vocabulary difference between monolinguals and bilinguals decreased over time. In addition, children with LI had weaker auditory and visual sustained attention skills relative to TD children, while no differences between monolinguals and bilinguals emerged. Auditory sustained attention mediated the effect of LI on vocabulary and morphology in both the monolingual and bilingual groups of children. Visual sustained attention only acted as a mediator in the bilingual group. Conclusions. The findings from the present study indicate that the overlap between the language profiles of children with LI and bilingual children is particularly large for vocabulary in early (pre)school years and reduces over time. Results furthermore suggest that the overlap may be explained by the weakened ability of children with LI to sustain their attention to auditory stimuli, interfering with how well incoming language is processed.