Recent research suggests that not only can children differentiate between two languages at an early age, but also show cognitive benefits from being exposed to a second language starting as early as infancy. In a study in 2009 of ‘crib bilinguals’, cognitive psychologists Agnes Kovács and Jacques Mehler used a visual test to measure cognitive flexibility in preverbal seven-month-olds. Kovács and Mehler wanted to see how quickly the infants could adapt to changing rules. They taught the infants a pattern consisting of speech-like sounds. At the end of the sequence, a visual reward in the form of a puppet would appear in one part of a computer screen. The infants were expected to learn that a given sound pattern predicated the appearance of the puppet in that location. Both bilingual and monolingual infants showed that they associated the sound sequence with the puppet’s location equally well by looking in the right place for the puppet to appear. But when Kovács and Mehler modified the sequence – and moved the puppet – the bilingual infants adjusted, switching their anticipatory gaze to the new location. The monolingual infants, however, continued to look for the puppet in the original location.