A new study, published Tuesday, shows how Zika infects and affects babies' brains. The New York Times writes that the study of 45 Brazilian babies, whose mothers contracted the virus during their pregnancy, is the most comprehensive yet. According to The Times, the impact is even more severe than just developing microcephaly, which is characterized by a smaller brain size. Many of the babies in the study also suffered damage to the cerebellum and to other important parts of the brain that control thinking and emotion. “It’s not just the small brain, it’s that there’s a lot more damage,” said Dr. Deborah Levine, one of the study's authors. “The abnormalities that we see in the brain suggest a very early disruption of the brain development process.” Three of the babies who were studied died within three days of birth.