In a recent research study, scientists utilized neuroimaging techniques to investigate how certain areas of the brain related to language and aging exhibit resilience. Their findings indicated that bilingual individuals with Alzheimer’s disease had a larger hippocampus compared to monolingual individuals when matched based on age, education, cognitive abilities, and memory. This observation points towards a possible connection between brain maintenance and bilingualism.
It is well-established that being bilingual offers cognitive advantages for older adults. Studies reveal that bilingualism can postpone the onset of Alzheimer’s disease by as much as five years in comparison to monolingual individuals. This factor is part of a broader range of lifestyle influences that may enhance brain resilience as people age.
A new research paper published in Bilingualism: Language and Cognition features findings from Concordia researchers who employed neuroimaging techniques to assess brain resilience in areas associated with language and aging.
The researchers observed that for bilinguals with Alzheimer’s, their hippocampal size was significantly greater than that of monolinguals, even after controlling for age, education, cognitive ability, and memory.
“We discovered increased brain matter in the hippocampus, which is crucial for learning and memory and is notably affected by Alzheimer’s,” explained Kristina Coulter, the lead author and PhD candidate, who collaborated with Natalie Phillips, a professor in the Psychology Department and a Concordia Research Chair (Tier 1) specializing in Sensory-Cognitive Health in Aging and Dementia.
They assessed the brain characteristics of both monolingual and bilingual older adults, categorizing them as cognitively normal, those at risk through subjective cognitive decline or mild cognitive impairment, and those diagnosed with Alzheimer’s.
Evidence of hippocampal atrophy was seen in monolingual individuals with mild cognitive impairment and Alzheimer’s, while bilingual individuals exhibited no changes in hippocampal volume throughout Alzheimer’s progression.
“In bilingual participants, the brain volumes associated with Alzheimer’s remained consistent across healthy older adults, those at risk, and those with the disease,” noted Coulter. “This finding suggests a potential link between bilingualism and brain maintenance.”
Localized Resilience
Brain resilience encompasses three key components: brain maintenance, brain reserve, and cognitive reserve, all integral to the brain’s capacity to adapt to age-related changes.
Brain maintenance refers to the ability of the brain to sustain its structure and functionality over time. Engaging in mentally stimulating activities like bilingualism, combined with a nutritious diet, physical exercise, sufficient sleep, and good sensory health, is thought to help safeguard the brain against deterioration.
Brain reserve pertains to the brain’s size and structural integrity. Brains with a larger reserve capacity can retain normal functionality despite damage or atrophy due to aging or diseases like Alzheimer’s.
Cognitive reserve indicates how the brain can utilize alternative pathways to preserve functionality in the event of damage or age-related shrinkage. Brains with a higher cognitive reserve can employ different regions than those typically associated with particular functions, such as language or memory, aided by lifelong cognitive flexibility.
Coulter pointed out that their study did not uncover any bilingualism-related brain reserve in language-specific areas or cognitive reserve in regions associated with Alzheimer’s.
“Being fluent in multiple languages is one of the many avenues to engage cognitive and social activities, which fosters brain health,” remarked Phillips. “This study was particularly valuable as it explored the impact of bilingualism on brain structure across the spectrum of dementia risk, from cognitively healthy individuals to those at an elevated risk for Alzheimer’s, and those diagnosed with the illness.”
The next steps for these Concordia researchers will explore whether multilingualism similarly benefits brain networks.
