Recent behavioral data suggest that lifelong bilingualism can help preserve cognitive strength in aging. Now a study in the January 2013 issue of The Journal of Neuroscience provides the first direct evidence of a neural basis for this bilingual cognitive control boost among older adults.

Researchers conducted two experiments using a perceptual task-switching paradigm with 110 participants. In the first experiment, older adults (mean age of 64.1 years) who are bilingual showed better perceptual switching performance than their monolingual peers.

In the second experiment, younger and older adult monolinguals and bilinguals completed the same perceptual task-switching experiment. As expected, researchers observed typical age-related performance reductions and functional magnetic resonance imaging activation increases.

However, like younger adults, bilingual older adults outperformed their monolingual peers while displaying decreased activation in the left lateral frontal cortex and cingulate cortex. Critically, this decrease of age-related overrecruitment of brain regions associated with bilingualism correlated directly with better task-switching performance. In addition, the lower blood oxygenation level-dependent response in frontal regions accounted for 82 percent of the variance in the bilingual task-switching reaction time advantage. These results may suggest that lifelong bilingualism offsets age-related declines in the neural efficiency for cognitive control processes.