As hormones surge, some brain areas shrink in what scientists say may be a fine-tuning that helps mothers bond with and care for their babies. As hormones surge, some brain areas shrink in what scientists say may be a fine-tuning that helps mothers bond with and care for their babies. Brain, Research, Pregnancy and Childbirth, Parenting, Hormones, Women and Girls, Nature Neuroscience (Journal), your-feed-science NYT > Science