Abstract:

The advantage of executive control brought by bilingual experience has long attracted much attention. However, the theoretical explanation and specific performance of the bilingual advantage are inconsistent. Some studies suggest that only some components of executive control exist bilingual advantage effect, which is conditional or there is no bilingual advantage effect on executive control. The present study suggests that the contradicted results of previous studies are probably due to an incongruent division on the components of executive control, especially confusing the concepts and task paradigms of interference control and response inhibition. In order to further clarify the internal mechanism of the bilingual advantage effect on executive control and identify which components of the executive control have a bilingual advantage, the current study distinguished interference control and response inhibition from traditional classification of inhibitory control and mainly focused on the bilingual advantage effect of interference control, response inhibition, and cognitive flexibility. At the same time, neglected variables such as age and language family, which were added to the study as moderators for the first time, as well as sample size, the proficiency of a second language, the acquisition age of a second language, and socioeconomic status were also included as moderating variables to explore their respective influences on the bilingual advantage effect of executive control.
Finally, the meta-analysis of 102 works of literature found that the bilingual advantage of executive control was marginally significant (g = 0.11), but the bilingual advantage disappeared after controlling for publication bias. Furthermore, the bilingual advantage of the interference control component was marginally significant (g = 0.08) without significant modulating effect. The bilingual advantage of the response inhibition component was significant (g = 0.21), and was moderated by proficiency of a second language. That is to say, the skilled bilinguals were more likely to show bilingual advantage compared to non-proficient bilinguals. Nevertheless, the bilingual advantage effect disappeared after controlling for publication bias. At the same time, the cognitive flexibility component was moderated by age and publication year. To be more specific, a bilingual advantage was found in child bilinguals while not in adult bilinguals, and there was a more significant result of the bilingual advantage in recent publication years. In addition, whether native and second languages belong to the same language family also influenced the bilingual advantage effect on executive control to some extent. Different language families had larger effect size than the same language family, and response inhibition showed a bilingual advantage when the native and second language belonged to different language families. This suggests language family is an important moderating variable that has been overlooked in previous studies. Future research should further explore the influence of the distance between the native and second language on the bilingual advantage of executive control.
In summary, this study not only found a bilingual advantage effect on executive control, but more importantly, tested the need to separate interference control and response inhibition from traditional inhibitory control. After separation, a stable bilingual advantage effect was found only for the interference control component, and an unstable bilingual advantage effect was found for the response inhibition component. Given that no study has yet hypothesized a bilingual advantage effect on interference control component alone, the findings provide new ideas and certain references for future exploration in the related field. Moreover, in explaining whether bilingual experience can lead to generalized cognitive advantage, the specific effects of language characteristics and the language using subjects, on different cognitive components of executive control should be fully considered.

Key words: executive control, bilingual advantage, interference control, response inhibition, meta-analysis