Language diagnostics in multilingual children: study of a scientifically based protocol to differentiate typical bilingual development from a developmental language disorder

Flemish primary education has 20-25% multilingual children (Jaarboek Statistiek Vlaams onderwijs, 2019). Both ASHA (2004) and IALP (2011) emphasize that multilingual children require appropriated diagnostics. However, to date there is no scientifically based protocol for language diagnostics in this heterogeneous and complex population. Master's theses LAW showed that, among other things, spontaneous language analysis in both native language and Dutch is useful. In addition to behavioural research, experimental EEG research also offers possibilities for the future. By measuring brain responses while listening to natural speech in Dutch as well as in the native language, researchers could objectively and passively map language processing and language dominance in multilingual children, without requiring knowledge of the native language by the tester. Despite its potential and applications in adults, this EEG technique has not yet been applied to multilingual children. Further research should determine which behavioural and EEG methods are sensitive, specific and feasible in clinical practice in the short and long term. This will lead to social and economic valorisation by (a) reducing under- and overdiagnosis of language development disorders in multilingual children, (b) faster initiation of tailored interventions, and (c) developing expertise of speech therapists in the field of developmental language disorders in multilingual children.