Specific language impairment in language-minority children from low-income families

Background: Recent evidence suggests that Specific Language Impairment (SLI) might be secondary to general cognitive processing limitations in the domain of executive functioning. Previous research has focused almost exclusively on monolingual children with SLI and offers little evidence-based guidance on executive functioning in bilingual children with SLI. Studying bilinguals with SLI is important, especially in the light of increasing evidence that bilingualism can bring advantages in certain domains of executive functioning.
Aims: This study seeks to determine whether executive functioning represents an area of difficulty for bilingual language-minority children with SLI and if so, which specific executive processes are affected.
Methods and procedures: This cross-cultural research was conducted with bilingual children from Luxembourg and monolingual children from Portugal who all had Portuguese as their first language. The data from 81 eight-year-olds from the following three groups was analyzed: (1) 15 Portuguese-Luxembourgish bilinguals from Luxembourg with an SLI diagnosis; (2) 33 typically developing Portuguese-Luxembourgish bilinguals from Luxembourg; (3) 33 typically developing Portuguese-speaking monolinguals from Portugal. Groups were matched on first language, ethnicity, chronological age and socioeconomic status, and they did not differ in nonverbal intelligence. Children completed a battery of tests tapping: expressive and receptive vocabulary, syntactic comprehension, verbal and visuospatial working memory, selective attention and interference suppression.
Results: The bilingual SLI group performed equally well to their typically developing peers on measures of visuospatial working memory but had lower scores than both control groups on tasks of verbal working memory. On measures of selective attention and interference suppression, typically developing children who were bilingual outperformed their monolingual counterparts. For selective attention, performance of the bilingual SLI group did not differ significantly from the controls. For interference suppression the bilingual SLI group performed significantly less well than typically developing bilinguals but not monolinguals.
Conclusions and implications: This research provides further support to the position that SLI is not a language-specific disorder. The study indicates that although bilingual children with SLI do not demonstrate the same advantages in selective attention and interference suppression as typically developing bilinguals, they do not lag behind typically developing monolinguals in these domains of executive functioning. This finding raises the possibility that bilingualism might represent a protective factor against some of the cognitive limitations that are associated with SLI in monolinguals.