Then researchers used functional magnetic resonance imaging (fMRI) -- which measures brain activity based on blood flow and oxygen levels -- to scan the brains of the women as they viewed photos of their children and their dogs. These pictures were alternated with those of unfamiliar children and dogs. Each recruit also rated images based on things like pleasantness and excitement.
The team found striking similarities and differences in how various regions reacted. Brain areas linked to emotion, reward, affiliation, visual processing, and social interaction all showed increased activity when they viewed either their own child or dog, but not with unfamiliar kids and hounds.