Life long bilingual speakers showed symptoms of dementia four years later
In a 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.
The 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.
Source: 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.
The 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
Ellen Bialystok, York University and Fergus Craik, Rotman Research Institute
Abstract: 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.
Source: Canadian Society for Brain, Behaviour and Cognitive Science 15th Annual Meeting
EEG Recordings prove learning foreign language can sharpen our minds--
Scientists now say that the more foreign languages we learn, the more effectively our brain reacts and processes the data accumulated in the course of learning.
Abstract: ...' We found that larger number of previously acquired languages and earlier average age of acquisition (AoA) predicted greater response increase to novel non-native word-forms. This suggests that early and extensive language experience is associated with greater neural flexibility for acquiring novel words with unfamiliar phonology. Conversely, later AoA was associated with a stronger response increase for phonologically native novel word-forms, indicating better tuning of neural linguistic circuits to native phonology. The results suggest that individual language experience has a strong effect on the neural mechanisms of word learning, and that it interacts with the phonological familiarity of the novel lexicon..." see full article
Further 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 24, 2005.
Kimpaa et. al Individual language experience modulates rapid formation of cortical memory circuits for novel words, Scientific Reports, 2016.