When you consider the challenges for the brain, it’s no wonder most of us find learning a language so
demanding. We have many different memory systems, and mastering a different tongue requires all of them.
There’s procedural memory – the fine programming of muscles to perfect an accent – and declarative memory,
which is the ability to remember facts (at least 10,000 new words if you want to come close to native fluency,
not to mention the grammar). What’s more, unless you want to sound like a stuttering robot, those words and
structures have to make it to the tip of your tongue within a split second, meaning they have to be programmed
in both “explicit” and “implicit” memory.
Speaking extra languages delays dementia by five years or more
That tough mental workout comes with big payoffs, however; it is arguably the best brain training you can try.
Numerous studies have shown that being multilingual can improve attention and memory, and that this can provide a “cognitive reserve” that delays the onset of dementia. Looking at the experiences of immigrants,
Ellen Bialystok at York University in Canada has found that speaking two languages delayed dementia
diagnosis by five years. Those who knew three languages, however, were diagnosed 6.4 years later than
monolinguals, while for those fluent in four or more languages, enjoyed an extra nine years of healthy
cognition.