long bilingual speakers showed symptoms of dementia four
report published in Neuropsychologia it is demonstrated
that people who are fully bilingual and speak both languages
every day for most of their lives can delay the onset of
dementia by up to four years compared with those who only
know one language. Studies have previously found evidence
that physical activity, social engagement and mental activities
such as reading and doing crossword puzzles can also help
stave off dementia.
study examined the effect of lifelong bilingualism on maintaining cognitive functioning
and delaying the onset of symptoms of dementia in old age. The sample was selected
from the records of 228 patients referred to a Memory Clinic with cognitive complaints.
The final sample consisted of 184 patients diagnosed with dementia, 51% of whom
were bilingual. The bilinguals showed symptoms of dementia 4 years later than
monolinguals, all other measures being equivalent. Additionally, the rate of decline
in Mini-Mental State Examination (MMSE) scores over the 4 years subsequent to
the diagnosis was the same for a subset of patients in the two groups, suggesting
a shift in onset age with no change in rate of progression.
Ellen Bialystok, Fergus I.M. Craik and Morris Freedman, Bilingualism as a protection
against the onset of symptoms of dementia, Neuropsychologia, Volume 45, Issue
2, 2007, Pages 459-464.
researchers said the extra effort involved in using more than one language appeared
to boost blood supply to the brain and ensure nerve connections remained healthy
— two factors thought to help fight off dementia. Research has previously found
that exercising the frontal lobes (the part of the brain which controls planning
and other high-level functions) can help build up a cognitive reserve which staves
off the onset of dementia. Previous research by Bialystok et.al., has suggested
that bilinguals have an advantage over monolinguals in nonlinguistic task involving
executive control. Two of the fundamental executive processes are selective attention
and task management which are centered in the frontal cortex of the brain.
Bilinguals may also show improved performance in a divided attention paradigm
compared to monolinguals
Dual Modality Monitoring
in a Classification Task: The Effects of Aging and Bilingualism
Bialystok, York University and Fergus Craik, Rotman Research Institute
Dual task paradigms in which two tasks must be performed simultaneously require
cognitive control to allocate attention between the tasks. In general, older adults
have more difficulty in these paradigms than younger adults as processing resources
diminish and cognitive control over those processes decline. However, lifelong
bilinguals have demonstrated enhanced cognitive control in a number of executive
function tasks, an advantage that increases in older adults as the decline in
these executive functions is less severe than it is for monolinguals. Therefore,
it is possible that bilinguals also show improved performance in a divided attention
paradigm compared to monolinguals and that this advantage increases with age.
Monolingual and bilingual participants who were younger (22 years) or older (60
years) adults performed in a dual-task classification paradigm. Visually (primary
task) and auditorily (secondary task) presented streams of information were classified
into two categories. Younger bilinguals were less disrupted than monolinguals
in the primary visual task when the secondary classification task did not require
much attention; older bilinguals were less disrupted than monolinguals in all
conditions. The results point to a benefit in allocating attention between
competing tasks that comes from being bilingual and an increase in that benefit
in older age.
Canadian Society for Brain, Behaviour and Cognitive Science 15th Annual Meeting
Readings and References:
Bialystok et. al., Executive
Control in a Modified Antisaccade Task: Effects of Aging and Bilingualism,
J. of Exp. Psychology, 2006.
Bialystok et. al., Effect
of bilingualism on cognitive control in the Simon task: evidence from MEG, NeuroImage