Proc. Natl Acad. Sci. USA 106, 6556–6560 (2009)

How do babies in bilingual households cope with life in two languages? New work suggests that the challenging environment may enhance infants' cognitive abilities before they even begin to speak.

Ágnes Melinda Kovács and Jacques Mehler of the International School for Advanced Studies in Trieste, Italy, trained 40 infants aged 7 months from monolingual or bilingual households to anticipate a visual reward after a spoken cue. When the visual reward — a picture of a puppet — was shifted from one side of the computer screen to the other, bilingual infants were better able to adapt to the change and shift their gaze.

The research indicates an enhancement in executive function, a cognitive control mechanism that may aid the simultaneous acquisition of two languages.