Executive functions and Specific Language Impairment (SLI) A cross-cultural study with bi- and monolingual children from low income families in Luxembourg, Portugal, and Brazil

Research questions. Our aim was to (a) seek cross-cultural evidence for executive functioning deficits in children with specific language impairment (SLI); (b) explore whether a similar pattern of deficits emerges in monolingual and bilingual children with SLI from low income families.
Methods. We present data on bilingual and monolingual children from Luxembourg, Portugal, and Brazil who all speak Portuguese as their first language and were tested on the same battery of language and executive function measures. The data from 124 eight-year-olds from five different groups was analyzed: (1) 15 Portuguese-Luxembourgish bilingual children from Luxembourg with SLI (Bi-SLI); (2) 33 typically developing Portuguese-Luxembourgish bilingual children from Luxembourg (Bi-TD); (3) 33 typically developing monolinguals from Portugal (Mo-TD/Pt); (4) 18 monolinguals from Brazil with SLI (Mo-SLI); (5) 25 typically developing monolinguals from Brazil (Mo-TD/Br). Groups were matched on chronological age, socioeconomic status, and nonverbal intelligence. Children completed a range of measures tapping vocabulary, grammar, verbal and visuospatial working memory, and cognitive control.
Results. Despite significant differences in their language and verbal working memory performance (SLI<TD), groups exhibited comparable performance on visuospatial working memory tasks. On cognitive control the following pattern emerged: Mo-TD/Pt < Bi-TD; Bi-SLI = Mo-TD/Pt; Mo-SLI < Mo-TD/Br.
Conclusion. The study provides no evidence of domain-general deficits in working memory in SLI. Visuospatial working memory difficulties might not be specific to SLI but represent one of many risk factors that can compromise language learning. Our data is consistent with the position that a bilingual experience stimulates the development of cognitive control that is involved in dealing with conflicting information. Notably, our results indicate that mechanisms of cognitive control might be deficient in monolingual but not in bilingual children with SLI raising the possibility that bilingualism might represent a protective factor against some of the cognitive limitations in SLI.