According to a study conducted by Princeton University and published in Psychological Science (January), infant and adult brains are in sync during natural play with brain activity rising and falling simultaneously as they share toys and eye contact.

For the study, researchers tracked the neural coordination of adults and infants while they played with toys, or while adults read a book and/or sang to children. The study also recorded data while adults switched off eye contact during interactions.

Researchers found that during face-to-face sessions, the brains of infants and adults were synchronised and when adults and toddlers turned away from each other, their synchronisation disappeared. “While communicating, adults and children form a feedback loop. That is, the adult’s brain seems to predict when infants would smile, with infants’ brains anticipating when an adult would use more ‘baby talk,’ and both brains tracked joint eye contact and joint attention to toys. So, when infants and adults play together, their brains influence each other in dynamic ways,” says Elise Piazza, a scholar in the Princeton Neuroscience Institute.