Have you ever noticed how babies get hooked the moment someone makes eye contact with them? That eye contact is not only cute; it may also send a powerful message to a baby. For years, scientists have been investigating whether social messages like eye contact and baby talk do more than engage babies. They may help synchronize babies’ brains with adult brain waves. But the biggest question remained: Does it actually help babies learn?

A new study, published in Nature Communications, offers an answer. Scientists found that 9-month-old infants were able to learn a novel language when the face in a video looked directly at them with fully visible eyes.

Using electroencephalography, or EEG, brain scanning, scientists detected a kind of “neural handshake” between the adult’s and infant’s brains, synchronized through eye contact.