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

Background:
This study seeks to determine whether executive functioning represents an area of difficulty for bilingual children with SLI and if so, which specific executive processes are affected.
Methods:
The data from 81 eight-year-olds from the following 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, socioeconomic status, and nonverbal intelligence. Children completed 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.
Discussion:
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.