Bilingualism Delays Onset of Dementia

Dee writes with word of a Canadian study indicating that lifelong bilingualism delays the onset of dementia by 4 years. The scientists were reportedly "dazzled" by the results. From the article: "The researchers determined that the mean age of onset of dementia symptoms in the monolingual group was 71.4 years, while the bilingual group was 75.5 years. This difference remained even after considering the possible effect of cultural differences, immigration, formal education, employment and even gender as influencers in the results. "

Re:statistics

[dorpus]

Normally, we would test a difference in means between two populations by a t-test. If the sample size is large enough, then even a difference that is only a fraction of a standard deviation can be statistically significant. F-tests are used in ANOVA tables, and yes, they do assume normal distributions, as well as homoskedasticity (same variance). Assuming they performed a linear regression, then one can perform a Type I F-test (added-in-order test) or Type II F-test (added-last test). One can also talk about an overall F-test, testing whether any of the effects in the model are nonzero. However, as I indicated in another post, the study only had 184 patients from a single treatment center. There is selection bias, since the study only sampled patients who were already suffering from memory loss. How many other bilingual immigrants with memory loss are lurking in the general population, who aren't going to memory loss clinics due to lack of knowledge? Also, what method did they use to adjust for "cultural differences, immigration, formal education, employment and even gender" with only 184 patients? The study only proves that bilingual patients who arrived at a particular treatment center were, on average, 4 years older than monolingual patients. It does NOT provide a causal link between bilingualism and cognitive reserve.

Re:Stands to reason

[Anonymous Coward]

ANY language in addition to English. A couple of vietnamese engineer coworkers signed up (all it requires is a proficiency test performed by a translator), but I'd say about 2/3rds of the people I know who are doing it are signed up as Spanish. I'm considering just swallowing my pride and signing up, because it looks like the policy is here to stay. According to wiki 7.37% of the city population is Hispanic or Latino (compare to 35.5% statewide), so it's pretty ridiculous...but a free $7200/year is worth my pride.

Re:Any language?

[Knutsi]

This will be guesswork on my behalf (not yet a doctor), but if I was to make an uneducated guess as to what causes this, i would suggest it is the constant increased level of activity in the brain of a multilingual person. It makes sence, that you have to engage larger patterns of knowledge when navigating between languages. If you learn a thing in one language, you also learn it in a second. If you know 10.000 words in two languages, I'm quite sure this accounts for quite a bit of added activity in the learning process, and is contsantly being stimulated by life around you. It should suggest that the more languages you know, the better the effect.

People claim that memorising a few things every day, such as learning a poem, keeps your mind kicking beyond the average age. I'm not sure this is a the actual case, but it is interesting.

(What the article fails to address is wether these people where speaking the language activly, or if they just knew it. I would take it there is a bit of a difference)

The patterns of a programming language is probably not being stimulated very much in your head as you move through the world, and I think it's scope is quite narrow. I'd doubt simply knowing one will have an effect, but maybe if you programme allot, the challenge of constructing systems and flows should be an interesting challenge for the mind, hopefully keeping it young (:

Re:Cause or effect?

[Monkelectric]

It seems really strange now to hear well-off Americans complain that learning languages is "too hard" and requires special talent

Learn some neurology then. The brain looses its plasticity for languages after the age of about 14. It *IS* extremely difficult to acquire a language after that age -- and if you do it is actually stored in a physically different location in your brain than your primary language.

This is the same reason that people who don't learn to read after a certain age almost *NEVER* learn to read.

The human brain has windows during which it is most receptive to acquiring new abilities. After those windows expire it is very difficult and in some cases impossible to acquire those abilities.

So blame the American educational system. Most language courses are offered at the freshman level of high school -- about the age of 15.

Re:I do a wee bit better than that.

[christophe]

in Western Europe it is de rigueur to speak at least three languages.

Well, Western Europe is a big place with many different nations. You can expect people from small countries, like Swiss or Belgians, to be fluent in one or two foreign languages, and people from Sweden or Danemark to speak very good English and often German. But the average French barely speaks enough English for international business (with many exceptions), and English people don't even have to learn another language. Situation seems better in Germany, at least for English. IMHO, that has more to do with the educational system and motivation than anything else. Exposure to foreign content (most films in original version with subtitles on TV for example, as in Danemark) is another key.

(Spoken as a French which speaks three languages).

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:Cause or effect?

[GeckoX]

So very very true.

I went through French immersion, spoke it completely fluently. Partook in exchanges to both Quebec and France, no problem whatsoever. Over 15 years ago now.

Not a lot of french is spoken in the greater Toronto area, and thus I've lost the ability.

Now, I am quite certain that if I was thrown into a french speaking environment, I would very likely pick it up again quite quickly. But it's certainly not an ability I can just pull out at my own whim anymore.

Re:Stands to reason

[Lijemo]

If your second language is Swahili and you work in Vermont -- well, probably not.

Actually, Burlington VT is a refugee resettlement center. There are small numbers of people speaking so many languages there that the second-most common language (after English) is "other." This makes life interesting for the public library with regard to forign-lagugage collection development and ESL classes-- and I suspect it makes things interesting for municipal servieces as well.

Truth is, in a municipal setting, you never know when Swahili (or any other language) will be very useful to know.