Multilingual Language Experience Affects Cognitive Function and Brain Connectivity
Post by Lina Teichmann
The takeaway
Multilingual children were shown to have enhanced executive function in comparison to monolingual children. In addition, functional connectivity in specific brain areas could be used to predict multilingual effects. This highlights that multilingualism has an effect on the brain and behaviour early on in development.
What's the science?
Being able to use several languages has been suggested to enhance executive function, as multilinguals must activate and suppress their known languages depending on the situation. This constant need to switch and juggle between languages may enhance attention and working memory. Recent studies, however, have failed to replicate these effects, and this failure may be partially due to high variability between multilinguals, age of foreign-language acquisition, level of proficiency, and the degree to which the language is used in daily life. This week in PNAS, Kwon and colleagues examined whether multilingualism in children affects executive function and brain connectivity.
How did they do it?
Using data from a large dataset of more than 1000 children (Adolescent Brain Cognitive Development, ABCD), the authors compared behavioural performances of monolingual and multilingual children with regard to working memory and attention tasks. In addition, whole-brain functional connectivity (correlated fluctuations in brain activity across different brain regions) was assessed by training a computer algorithm to distinguish the groups of children based on the connectome data only. The connectome was then further examined by comparing whether there are specific brain areas that are particularly engaged when the children perform a task and during a rest scan. To combine behaviour and neural data, the authors also used modeling approaches to predict behaviour from brain connectivity data alone.
What did they find?
The behavioural data showed that multilingual children performed better at working memory tasks. Using the functional connectivity data alone, the authors further found that a computer algorithm could differentiate between monolingual and multilingual children. There were stronger connections between prefrontal and occipital brain areas in multilingual children than monolingual children during rest, highlighting that multilingualism has an effect on brain areas usually associated with complex cognitive functions and visual processing. To quantify the relationship between brain and behaviour for memory function for the two groups of children, the authors used connectome-based predictive modeling. The results showed that the connectome of multilingual children engaging in a working-memory task can predict behavioural performance on working-memory tasks. In contrast, this was not possible for monolinguals.
What's the impact?
The advantages of multilingual language experience have been hotly debated over the last few decades. Kwon et al. demonstrated that there is indeed an effect of multilingualism on the developing brain and behaviour. This work provides important insight into how language can impact our brain development.