USA Today reports on a new study in the journal Neurology in which Indian researchers assessed the associations between bilingualism and onset of dementia among 648 patients (391 bi/multilinguals) who were all diagnosed with dementia. Controlling for lots of things like literacy levels, immigration status, education, and gender, the researchers found that onset of dementia was delayed by approximately 5 years among bilinguals as compared with their monolingual counterparts. This study is not particularly novel, but it's interesting because: 1) it's coming out of India and not Canada; 2) it's a naturalistic, not a laboratory study; 3) it takes into account natural variations in the general population like literacy, immigration, etc.; 4) it's messy, with missing data and the like. The analyses are simple and the findings are basic but compelling. Using multiple languages in daily life requires greater cognitive attention and flexibility, resulting in greater mental stamina which delays onset of dementia. Cite for the actual study is: Alladi, S. Bak, T.H., Duggirala, V., Surampudi, B., Shailaja, M., Shhukla, A.K., Chaudhuri, J.R., & Kaul, S. (2013). Bilingualism delays age at onset of dementia, independent of education and immigration status. Neurology, 81, 1 - 7.
Indian study shows that bilingualism preserves cognition, even if you can't read
Washington Post article covers heritage language revival attempts by children of immigration
Nice article in the Washington Post magazine profiles a young man named Daniel Chen, a second generation child of Chinese immigrants from Shanghai, and tells the story "about the isolating power of a lost mother tongue and an education spent retrieving it". Like many such stories, it is complex, involving movement, translation, frustration, and determination. The author details the phenomenon of first language attrition, which I have documented in my own research, spends some space on the critical period, and does an overall nice job of linking language development and loss within the larger contexts of immigration and family cohesion. Definitely worth a read.