Sunday, May 1, 2022

Can Bilingualism Prevent Age-Related Cognitive Decline?



Historically, the average human life expectancy has experienced an upwards trend. Around the world, life expectancy has increased by an average of 6 years between 2000 and 2020. As this value increases, the issue of age-related diseases becomes more prominent and more critical to deal with in our society. As of now, there are 6 million Americans living with Alzheimer’s, and this number is expected to reach 13 million by 2050. In 2020, there were 930,000 people diagnosed with Parkinson’s, and by 2030 this number is expected to reach 1,200,000. As average life expectancy increases, the number of people with degenerative diseases will also increase. As we have not yet been able to find pharmaceutical solutions to disorders like this, it is of utmost importance that we find ways to increase cognitive reserve and prevent age-related cognitive decline. Although there are many methods of increasing cognitive reserve, such as exercise,hobbies,and games, recently more and more research is demonstrating that bilingualism has a role in ameliorating cognitive reserve by increasing activity and  connectivity between brain regions.


In our neuroscience class, we read Dr Berken’s research paper, “Early bilingualism, language attainment, and brain development”. This paper discusses the neuroplasticity that occurs in the brain as a result of simultaneous and sequential bilingualism. The two groups discussed in this paper are simultaneous and sequential English and French speakers in MontrĂ©al, Canada. It was found that simultaneous bilinguals had increased connectivity between several brain areas when compared to sequential bilinguals, implying that the later the age of acquisition is, the less communication there can be between different brain areas. Using resting-state fMRI, he found that simultaneous bilinguals had “greater connectivity between the left and right inferior frontal gyrus (IFG), as well as between the IFG and the brain areas involved in language control”. Berken also reports that both groups activated the same brain areas during a test for speech production that involved reading aloud, but the sequential bilinguals had increased activation in several different brain areas when reading aloud in their second language. Berken concludes that the later a language is learned, the more active the brain will become in activities such as speaking and reading, whereas learning a language earlier results in less brain activity due to the increased connectivity between brain regions. 


The article “Add Bilingualism to the Mix: L2 Proficiency Modulates the Effect of Cognitive Reserve Proxies on Executive Performance in Healthy Aging” by Gallo et al investigates how bilingualism can develop cognitive reserve. Cognitive reserve is essentially how well the brain can adapt to using alternative methods and modes of operation when faced with obstacles. Greater cognitive reserve means that an individual has a better chance at compensating for symptoms of neurodegenerative diseases such as multiple sclerosis, dementia, and Parkinson’s, and it also means that the individual can function better when exposed to unexpected stressful circumstances. This study was performed in an online format using cognitively healthy bilingual adults age sixty and above. Researchers found that bilingualism was a strong contribution to the development of cognitive reserve, claiming that it “plays an important role in mitigating cognitive decline and promoting successful aging”. The results of this study also report that “bilingualism supports the maintenance of optimal executive performance during senescence”. Although this study does not differentiate between sequential and simultaneous bilinguals, it still demonstrates that the increased activity in bilingual brains leads to an overall enhanced “executive network capacity, efficiency, and flexibility”. 


All in all, living in a society where the average life expectancy is constantly increasing also means that the number of age-related cognitive decline disorders is also concurrently rising. These numbers are rising faster than researchers and scientists are able to find pharmaceutical ways of managing and curing disorders like Parkinson’s, Alzheimer’s, and multiple sclerosis, meaning that we must look at other, non-pharmacological methods of battling these diseases. Learning a new language is one simple way of increasing brain activity, synaptic plasticity, and cognitive reserve. 



Works cited

Berken, Jonathan A., et al. “Early Bilingualism, Language Attainment, and Brain Development.” Neuropsychologia, Pergamon, 1 Sept. 2016, https://www.sciencedirect.com/science/article/pii/S0028393216303293. 


Gallo, Federico, et al. “Add Bilingualism to the Mix: L2 Proficiency Modulates the Effect of Cognitive Reserve Proxies on Executive Performance in Healthy Aging.” Frontiers in Psychology, Frontiers Media S.A., 31 Jan. 2022, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8841471/. 

“What Is Cognitive Reserve?” Harvard Health, 21 Sept. 2020, https://www.health.harvard.edu/mind-and-mood/what-is-cognitive-reserve








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