Speaking more than one language has some advantages beyond ordering food in the local tongue -- psychologists believe that bilingualism has many other positive side effects. Now, researchers have evidence connecting bilinguals' talents to stronger so-called executive control in the brain.
Much has been made recently about growing up learning more than one language, as about one in five do. There's evidence that children who grow up speaking two languages may be more creative, that bilingualism might stave off dementia, and that bilinguals are better at tasks that involve switching attention between different objects. That led some researchers to suspect that speaking two languages might improve our brains' executive functions, the high-level circuits that control our ability to switch between tasks, among other things.
To get a little more sense of the matter, Andrea Stocco and Chantel Prat of the University of Washington screened 17 bilingual and 14 monolingual people for language proficiency and other factors and then tested them using a series of arithmetic problems. Each problem was defined by a set of operations and two inputs -- divide x by two, add one to y, and subtract the second result from the first, for example -- with x and y specified uniquely for each problem. First, participants ran through 40 practice problems using just two operation sets. Next, they went through another 40 problems, this time a mix of 20 new ones, each with a unique set of operations and inputs, and another 20 featuring the previously studied arithmetic operations, but with new inputs for x and y. Finally, the groups worked through 40 more problems, again a mix of familiar and novel, but this time, they completed them inside a fMRI brain scanner.
While bilinguals and monolinguals solved the problems with equal accuracy and took about the same amount of time on arithmetic with familiar sets of operations, bilinguals beat out monolinguals, on average, by about half a second on novel problems. What's more, fMRI results showed that the basal ganglia, a brain region previously linked to learning about rewards and motor functions, responded more to novel math problems than old ones, but only in bilinguals.
That's interesting, Stocco says, because more recent studies suggest the basal ganglia's real role is to take information and prioritize it before passing it on to the prefrontal cortex, which then processes the information. If that's correct, the new results suggest that learning multiple languages trains the basal ganglia to switch more efficiently between the rules and vocabulary of different languages, and these are skills it can then transfer to other domains such as arithmetic.
"Language is one of the hardest things the brain does," Prat says, though we often realize that only when we try to learn a new language -- a task that is "at least an order of magnitude" more difficult than learning the first one. But just as working on your core has benefits outside the gym, working your basal ganglia hard may be the key to promoting other cognitive skills, especially your hidden math genius.