Being able to speak two languages has all sorts of benefits. A possible long-term benefit may be surprising, though. You might end up sharper in old age.
A recent study tested how well older adults could switch between mental tasks. Some spoke two languages, and some spoke only one language.
The experiments showed that the bilingual adults appeared to have more "cognitive flexibility." They could switch between tasks faster and more accurately than those who spoke just one language.
The study, led by Brian T. Gold, from the Department of Anatomy and Neurobiology at the University of Kentucky, aimed to find evidence that being bilingual really does contribute to your cognitive abilities as you grow older.
The researchers conducted two experiments for the study. The first one involved 15 older bilingual adults (average age 64) and 15 adults who spoke only one language (average age 63).
The second experiment involved four groups of participants: 20 younger bilingual adults, 20 younger adults who spoke only one language, 20 older bilingual adults and 20 older adults who spoke only one language.
None of the participants had a history of head injury, concussion, color blindness, stroke or a neurological or psychiatric disorder. All were right-handed.
The participants were given an extensive vocabulary test to assess their proficiency in English. They were also given a memory test and an IQ test that lacks bias for cultural background or verbal abilities.
Then, for the actual experiments, the participants took a computer test that required them to switch between two tasks, identifying an object's shape and identifying an object's color. The results were adjusted to account for age, gender, educational level, intelligence and socioeconomic background.
The only difference between the experiments, other than the participants, was that the second group had brain scans done with function magnetic resonance imagine (fMRI) at the same time they were doing the task.
In the first experiment, there was no real difference in speed or accuracy between the two groups for most of the tasks, but the bilingual adults were slightly faster on the parts where they had to switch quickly between shape identification and color identification.
In the second experiment, the younger adults predictably performed better in speed and accuracy than the older adults, but there was no difference between the bilingual and single-language younger participants.
Meanwhile, the older bilingual adults performed the task faster than the older single-language adults. The older bilingual adults also showed lower activity levels in two parts of their brains even while they did better on the task than the older adults who spoke only one language.
That means the older bilingual adults used less brain power to do the task and still did it more quickly than the older adults who spoke only one language.
“This suggests that bilingual seniors use their brains more efficiently than monolingual seniors,” Dr. Gold said in a release about the study. “Together, these results suggest that lifelong bilingualism may exert its strongest benefits on the functioning of frontal brain regions in aging.”
The study was published January 8 in The Journal of Neuroscience. The research was funded by the National Institutes of Health and the National Science Foundation. The authors declared no conflicts of interest.