Does the Bilingual Advantage in Cognitive Control Exist and if so, what are Its Modulating Factors? A Systematic Review

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 October 31, 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 non-standardized 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.

Individual Variation and the Bilingual Advantage - Factors that Modulate the Effect of Bilingualism on Cognitive Control and Cognitive Reserve

“…They study all kinds of monolingual, bilingual, and multilingual individuals with all kinds of experimental tasks, making comparisons of their results and interpretation of all of the results difficult and often impossible. This might explain why the results on the bilingual advantage in cognitive control [15] and the results on the cognitive reserve-enhancing effect of lifelong bilingualism and protection against dementia [54] are mixed.…”

“…Thirdly, the use of (standardized) objective proficiency measurements is strongly recommended [49]. Moreover, larger study samples are needed [15]. So far, small study samples have been often used in research on the bilingual advantage in cognitive control and, to a lesser degree, in research on bilingualism and the cognitive reserve hypothesis.…”

“…First, having an overview of the results to date on research on bilingual advantage in cognitive control is important. In order to do so, Van den Noort and colleagues [15] conducted a review study. They searched 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.…”

“…In the second, smaller part of our special issue, we focused on the cognitive reserve hypothesis [16]. Bilingualism has been put forward as a life experience that, similar to musical training [51] or being physically active [52], may boost cognitive performance [15] and slow age-related cognitive decline [53]. In the first study conducted by Van den Noort and colleagues [54], the literature is reviewed in order to provide an overview of the state-of-the-art results in the field.…”

“…The aim of this special issue is to provide an overview of studies published so far on bilingualism and cognitive control, as well as their findings, in an effort to determine whether or not a bilingual advantage in cognitive control really exists. Furthermore, the focus will be on individual, as well as methodological, factors such as socioeconomic status [11], immigrant status and ethnicity [12], cognitive capacity [13], culture [14], age [15], and experimental task used [15], all factors that might modulate the bilingual advantage in cognitive control. Finally, we will take a closer look at the cognitive reserve hypothesis [16] that states that individuals with more cognitive reserve have a reduced risk of suffering from brain diseases, such as dementia [17].…”