No abstract

Recently, doubts were raised about the existence of the bilingual advantage in cognitive control. The aim of the present review was to investigate the bilingual advantage and its modulating factors. We searched the Medline, ScienceDirect, Scopus, and ERIC databases for all original data and reviewed studies on bilingualism and cognitive control, with a cut-off date of 31 October 2018, thereby following the guidelines of the preferred reporting items for systematic reviews and meta-analysis (PRISMA) protocol. The results of the 46 original studies show that indeed, the majority, 54.3%, reported beneficial effects of bilingualism on cognitive control tasks; however, 28.3% found mixed results and 17.4% found evidence against its existence. Methodological differences seem to explain these mixed results: Particularly, the varying selection of the bilingual participants, the use of nonstandardized tests, and the fact that individual differences were often neglected and that longitudinal designs were rare. Therefore, a serious risk for bias exists in both directions (i.e., in favor of and against the bilingual advantage). To conclude, we found some evidence for a bilingual advantage in cognitive control; however, if significant progress is to be made, better study designs, bigger data, and more longitudinal studies are needed.

Language switching experience is assumed to have an effect on domain-general control abilities in bilinguals, but previous studies on the relationship between these two variables have generated mixed results. The present study investigated the effects of bilingual experiences on the interaction between language switching and domain-general control. Thirty-two Dutch–French bilingual young adults executed a bilingual categorisation task to assess their language switching abilities and a Simon task to assess domain-general control. The results show that global response times on the Simon task were correlated to the forward switch cost (from L1 to L2); moreover, interestingly, the forward switch cost was found to be related to recent language exposure but not to the age of second language acquisition. We suggest a monitoring account of language switching to integrate the first finding with previous studies and we interpret the second finding as support for the adaptive control hypothesis.

Throughout the past century, the effects of bilingualism on general cognition have been extensively explored. Studies evolved from a negative to a more positive perspective, but longitudinal assessments of effects of bilingualism are scarce. This study investigated the long‐term effect of becoming a bilingual on the development of general intelligence and cognitive control. We followed 27 five‐year‐old children initiating bilingual kindergarten and 27 age‐matched controls enrolled in monolingual kindergarten. The two groups were similar with regard to socioeconomic status. At baseline, both groups spoke only French and performed equally on measures of intelligence, cognitive control, and verbal fluency. One year later, all children were tested again. Results revealed that, after 1 year, both groups improved similarly on verbal fluency and cognitive control. However, only children attending bilingual kindergarten improved significantly on intelligence, indicating that cognitive practice gained from acquiring a second language may improve general cognitive abilities assessed by intelligence tests, outside the verbal domain.