Voluntarily switching between languages is good for the brain

The I+DEL group at the UIB publishes three studies on the relationship between bilingualism and cognition 

During the past decades, several studies have found evidences that support the concept labeled ‘bilingual advantage’. This concept refers to the supposed benefits that speaking two languages in daily life can have on the cognitive abilities needed in order to adapt oneself to the requirements of a changing context. Nonetheless, there have also been several scientific studies in which results did not support the existence of the bilingual advantage, thus generating a controversy, still open to this date. This mixture of results, in favor and against the existence of the benefits of bilingualism, has generated a shift in the way we understand bilingualism. It was first conceived as an all or nothing phenomenon, you were bilingual or not; now it is understood as interaction of factors that can be observed in a continuum. For example, one can learn two languages simultaneously, or one after the other. It is also possible that the frequency of switches from one language to the other varies from one speaker to the other. This versatile conception of bilingualism served as a guideline for research in an attempt of improving our understanding of the influence of the factors related to bilingualism and executive control. With this in mind, the research group I+DEL (Investigation on Development, Education, and Language) has tried to clarify the true influence of bilingualism on executive control and to explain the ambiguous results in this field of study.

In a first study, we identified the linguistic factors that could contribute to a better understanding of the relation between bilingualism and executive control abilities. We collected information regarding linguistic factors form more than one hundred young bilinguals (Catalan and Spanish speaking): the age of acquisition of second language, the linguistic proficiency in that second language, and daily average frequency of language switching. Regarding language switching, participants reported its direction (whether changing to the first or second language) and type of change (whether language switching was involuntary or guided by the surrounding context). After that, this same participants conducted different computer-based experimental tasks that assessed three dimensions of executive control: inhibition of non-relevant information, working memory and cognitive flexibility (task shifting capacities). The results obtained depicted a relation between frequent and intentional changes to the second language (from Catalan to Spanish, in this case) and a more efficient executive control, better working memory and greater cognitive flexibility. On the other hand, involuntary (unconscious) language switching was associated with worse inhibitory abilities. The results of this study suggest that frequent language switching – but not age of second language acquisition nor proficiency in that language – can have effects on executive components. The study was recently published in the journal Bilingualism: Language and Cognition. Therefore, the daily frequency of language switching, altogether with how we do it depending on the linguistic context, might be the key for a better understanding of the diverse results obtained in the field of bilingualism and cognition.

In a second study, we evaluated more participants, obtaining a sample of 180 young bilinguals, whose data was analyzed through the structural equations model (SEM). This statistical analysis allows for a more detailed description of the relation among the different factors involved in this complex mechanism. This analysis verified that the frequency of natural language switching positively modulated executive control abilities in bilinguals, whilst age of acquisition of the second language and proficiency had no significant effect. Furthermore, the analysis indicated that the impact of the factor natural language switching had not only a global effect on general information processing, but also differential effects on the subcomponents of executive control. These results, which were published in the journal International Journal of Bilingualism, besides from helping to understand the relation between bilingualism and executive control, also highlight the relevance of the ability of linguistically adapting oneself to the context in a conscious and intentional way.

The next step was testing the existence of the bilingual advantage within a large sample of bilinguals from the Balearic Islands when comparing them with another group of monolinguals from Spain. For this purpose, we designed different experimental computer-based tasks in order to compare the performance of monolinguals and bilinguals on specific components of executive control, with the particularity that, in this third study, the experimental tasks were more demanding (complex) at a cognitive level than those used on previous studies. Tis decision was important, for results obtained in other studies seem to indicate that it is more difficult to find evidence of the bilingual advantage among young adults than in other age-related stages, since they find themselves at the developmental peak of cognitive abilities.  In this sense, cognitive complexity has been hypothesized as a key element that can be differential when comparing the cognitive abilities of monolinguals and bilinguals. Thus, the aim of this study was to test for the existence of bilingual advantage and, if found, to analyze its executive control components. The results of this research, which were published in the Language, Cognition and Neuroscience, revealed that bilinguals exhibit a response pattern that is slightly more precise than the one of monolinguals. However, no evidences were found so that to say that bilinguals have better abilities than monolinguals when comparing performance and accuracy in whichever of the executive control components. Actually, results suggested that, in tasks with moderate difficulties, bilinguals could even exhibit some disadvantage, but any difference disappeared when both groups were facing task with high difficulty.

Taken together, these three studies help us to better understand which are the factors that are involved in the development of better cognitive abilities, such as frequent and voluntary language switching. However, it does not seem that the influence of bilingualism generates an evident difference between bilinguals and monolinguals in specific aspects of executive control, not even when facing highly demanding tasks that, theoretically, should highlight these differences between these two linguistic populations.

References of the published Works:

López Penadés, R, Sánzhez-Azanza, V, Buil-Legaz L, & Aguilar-Mediavilla, E, & Adrover-Roig, D. (2020). Associations between natural language switching and executive control in early bilinguals. Bilingualism: Language & Cognition, 1-12. DOI: https://doi.org/10.1017/S1366728920000012

Sánchez-Azanza-V, López-Penadés, R, Aguilar-Mediavilla, E, &  Adrover-Roig, D (2020). Latent variable analysis on the interplay between language switching and executive control International Journal of Bilingualism, 1-19 DOI: https://doi.org/10.1177/1367006920902525

Sánchez-Azanza, V, López-Penadés, R, & Adrover-Roig, D (2019). More similitudes than differences between bilinguals and monolinguals on speeded and demand-varying tasks. Language, Cognition & Neuroscience, 1-17. DOI: https://10.1080/23273798.2019.1706752