Bilingual experience, particularly earlier L2 age of acquisition, predicts resilience in executive function—especially task-switching performance—in older adults with a history of COVID-19.
Key Findings
Results
Greater bilingual experience was associated with better executive function in a multivariate latent structure across the adult lifespan.
Study collected data from 312 community-dwelling individuals aged 18 to 80.
Partial least squares correlation (PLSC) analysis was used to extract latent relationships between multiple bilingual experience measures and a battery of EF task outcomes.
Individuals with earlier L2 age of acquisition (AoA) and greater L2 proficiency showed a multivariate association with executive function measures.
The most consistent behavioral expression of this association was observed in task-switching performance.
A continuous multivariate approach was used to help resolve controversies in the bilingualism and EF literature.
Results
Earlier L2 age of acquisition was most robustly associated with better nonverbal task-switching performance among older adults reporting a history of COVID-19.
The association was observed specifically in the older adult age group, suggesting age-moderated effects.
The finding held even when modeling COVID burden continuously (i.e., number of infections and recency of last infection).
The effect was specific to nonverbal task-switching performance rather than other EF measures.
This suggests bilingual experience may confer resilience against post-COVID EF decline in the most vulnerable older age group.
Background
Bilingualism was hypothesized to confer protection against COVID-related cognitive decline in older adults through bolstering cognitive reserve.
COVID-19 has been identified as a factor negatively affecting executive function in older adults.
Bilingualism has been previously associated with enhanced executive functions, particularly attentional control, and protection against cognitive decline in older age.
The study framed bilingualism's protective role within a cognitive reserve framework.
Two goals were defined: identifying a latent structure linking bilingualism and EF across the lifespan, and determining whether bilingualism protects against post-COVID EF decline in older adults.
Methods
The study used a continuous multivariate approach to bilingualism and executive function measurement to address controversies in the existing literature.
Multiple bilingual experience measures were included rather than a binary bilingual/monolingual classification.
A battery of EF task outcomes was employed rather than single measures.
PLSC analysis was the primary statistical method used to extract latent variable relationships.
Sample spanned the adult lifespan (ages 18 to 80), enabling examination of age-related moderation of bilingual effects.
Relevant covariates were included in the modeling approach.
Conclusions
Bilingual experience contributes to resilience in attentional control under flexible task-switching demands in older adults even in the context of COVID-19.
The authors conclude this finding demonstrates a protective role of bilingualism specifically for task-switching, a measure of cognitive flexibility.
The resilience effect was evident even accounting for COVID burden measured continuously.
The effect was most pronounced in older adults, consistent with a cognitive reserve account of bilingual advantage.
The findings were described as demonstrating that "bilingual experience contributes to resilience in attentional control under flexible task-switching demands in older adults even in the context of COVID-19."
What This Means
This research suggests that speaking more than one language may help protect older adults' thinking abilities from the negative cognitive effects of COVID-19. The study followed 312 adults ranging from 18 to 80 years old and measured both their bilingual experience (such as how early in life they learned a second language and how proficient they were in it) and their performance on a range of mental tasks that test executive functions—the brain's ability to plan, focus, and switch between tasks. Rather than simply comparing bilinguals to monolinguals, the researchers used a sophisticated statistical approach that captured the full range of bilingual experience and cognitive performance, helping to move past longstanding debates in the field.
The key finding was that older adults who had earlier and more extensive bilingual experience performed better on task-switching tests—a measure of mental flexibility—even if they had previously had COVID-19. This held true even when accounting for how many times someone had been infected and how recently, suggesting the protective effect is robust. The benefit was most clearly seen in older adults rather than younger ones, which aligns with the idea that lifelong bilingualism builds up a kind of 'cognitive reserve' that helps the brain withstand damage or disease-related decline later in life.
This research suggests that a lifetime of managing two languages may strengthen certain brain networks involved in attention and cognitive flexibility, and that this strengthening can provide a buffer against the cognitive consequences of COVID-19 in older age. While the findings do not establish that learning a second language will definitively prevent COVID-related cognitive problems, they add to a growing body of evidence that bilingual experience is associated with greater cognitive resilience in aging.
Grundy J, Pujols-Beltran M. (2026). Bilingualism predicts executive function resilience after COVID-19 in aging.. Proceedings of the National Academy of Sciences of the United States of America. https://doi.org/10.1073/pnas.2532470123