Non-verbal cognition as a predictor of linguistic outcomes in children with and without developmental language disorder

Developmental language disorder (DLD) is a persistent language disorder where children have difficulty understanding, learning, and using spoken language (Bishop, Snowling, Thompson, Greenhalgh et al., 2017). Whilst linguistic difficulties in children with DLD have been widely researched, the relationship between cognitive and linguistic processes are not as well-defined. This study follows on from a previous research project which investigated the relationship between cognition and language in children aged 7-10 years, with and without DLD. Our findings suggested that a combination of cognitive abilities are important for linguistic outcomes, namely non-verbal intelligence, working memory, and the speed of automatization. In this new study, we aim to build upon our previous findings as well as explore new factors such as analogical reasoning, language aptitude (grammatical sensitivity), and executive functioning (the role of inhibition). The rationale for investigating these predictors are as follows: Analogical reasoning is important for language learning, especially with regards to learning vocabulary and grammar. Previous research suggests that children with DLD may have impaired analogical reasoning (Krzemien et al., 2017; Leroy et al., 2012, 2014). An important part of this process is being able to focus on similarities and also disregard irrelevant information. In addition, Krzemien et al. (2017) highlight that children with DLD have difficulty with ​aspects of ​executive function, such as inhibition, and that this potentially influences analogical reasoning performance. Therefore, we explore the role of inhibition in relation to analogical reasoning. (Foreign) language aptitude is thought to be irrelevant to first language acquisition because it it is widely assumed that first language acquisition develops implicitly (see DeKeyser et al., 2010). However, there is evidence suggesting that it does matter and this makes sense, theoretically, in a usage-based framework of language acquisition. It also makes sense theoretically in the declarative-procedural framework: according to Ullman (2004, 2020), children with DLD compensate for problems with procedural learning by relying more on declarative memory – so by extension, aptitude may be relevant as well. In our study, we explore grammatical sensitivity. Lastly, our previous study investigated implicit statistical learning using a forced-choice embedded triplets paradigm, yet​​ participants​ (both with and without DLD)​, performed largely at chance. According to previous literature, children with DLD have difficulty with implicit statistical learning (Lammertink et al., 2017; Lum et al., 2014; Obeid et al., 2016). However, recent research highlights many issues with measuring implicit statistical learning, especially in children (see Arnon, 2019, 2020; Isbilen & Christiansen, 2022; Oliveira et al., 2022). In this study, we implement a new task to measure implicit statistical learning.