Full-term babies are born with a key collection of networks already formed in their brains, according to new research that challenges some previous theories about the brain's activity and how the brain develops. Researchers used functional MRI scanning to look at 'resting state' networks in the brains of 70 babies, born at between 29 and 43 weeks of development. They found that these networks were at an adult-equivalent level by the time the babies reached the normal time of birth.