The impact of bilingualism on executive functions and working memory in young adults

PLoS One. 2019 Feb 13;14(2):e0206770. doi: 10.1371/journal.pone.0206770. eCollection 2019.

Abstract

A bilingual advantage in a form of a better performance of bilinguals in tasks tapping into executive function abilities has been reported repeatedly in the literature. However, recent research defends that this advantage does not stem from bilingualism, but from uncontrolled factors or imperfectly matched samples. In this study we explored the potential impact of bilingualism on executive functioning abilities by testing large groups of young adult bilinguals and monolinguals in the tasks that were most extensively used when the advantages were reported. Importantly, the recently identified factors that could be disrupting the between groups comparisons were controlled for, and both groups were matched. We found no differences between groups in their performance. Additional bootstrapping analyses indicated that, when the bilingual advantage appeared, it very often co-occurred with unmatched socio-demographic factors. The evidence presented here indicates that the bilingual advantage might indeed be caused by spurious uncontrolled factors rather than bilingualism per se. Secondly, bilingualism has been argued to potentially affect working memory also. Therefore, we tested the same participants in both a forward and a backward version of a visual and an auditory working memory task. We found no differences between groups in either of the forward versions of the tasks, but bilinguals systematically outperformed monolinguals in the backward conditions. The results are analysed and interpreted taking into consideration different perspectives in the domain-specificity of the executive functions and working memory.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Auditory Perception
  • Executive Function*
  • Female
  • Humans
  • Male
  • Memory, Short-Term*
  • Multilingualism*
  • Neuropsychological Tests
  • Socioeconomic Factors
  • Visual Perception
  • Young Adult

Grants and funding

For this research, JAD has been partially funded by grant PSI2015-65689-P from the Spanish Government (http://www.ciencia.gob.es/), EA has been partially funded by grant PI2015-1-27 from the Basque Government (http://www.euskadi.eus/gobierno-vasco/departamento-educacion/), and MC has been partially funded by ERC-AdG-295362 grant from the European Research Council (https://erc.europa.eu/), by the AThEME project funded by the European Union (grant number 613465, http://www.atheme.eu/), and by grant Centro de Excelencia Severo Ochoa SEV-2015-0490 provided by the Spanish Government (http://www.ciencia.gob.es). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. There was no additional external funding received for this study.