A new look at the question of the bilingual advantage ; Dual mechanisms of cognitive control

Bilingualism has been associated with age-related cognitive advantage. It is important to study cognitive control mechanisms to better understand this phenomenon. We sought to examine proactive and reactive control, as measured by fast and slow responses, respectively. The neural underpinnings of these modes of control were studied in rigorously matched elderly monolinguals and bilinguals, using fMRI performance on a Simon task. The results indicate that bilinguals performed efficiently in proactive mode, as more activation and connectivity were observed in the monolinguals. On the other hand, the monolinguals functioned more efficiently in reactive mode, recruiting fewer brain areas than the bilinguals. These results suggest that bilinguals' function effortlessly and economically in proactive mode, which is preserved through lifelong use of languages, whereas monolinguals are efficient in reactive mode, which they use more often as a consequence of aging. Thus, frequent use in daily life contributes to efficient functioning in the respective mode of control.