On this Moment of Science Ya?l and Don discuss how parenting affects the brain.   Ya?l : On today's Moment of Science--wait a sec, Don, do you mind if I call home real quick?

Don: Now? In the middle of the show?

Y: Well, I'm worried about the baby. I just want to check that she's okay.

D: Okay. Sure. Go ahead. But let me tell you that you're going to look back on this and wonder whatever possessed you to do things like call home every five minutes and poke the baby over and over while she's sleeping to make sure she's still breathing.

Y: Hey, how do you know about that?

D: Because you're not alone. In fact, a study out of Yale University suggested that having a child may actually affect your brain function.

Y: There's a newsflash. I think it's the sleep deprivation.

D: Actually, it's more than that. In the study, researchers monitored parents' brain activity when they heard their child crying, or saw their child's picture. Interestingly, it turned out that some of the brain areas that were activated are the same as the brain areas that are overactive in patients with obsessive-compulsive disorder.

Y: Don, are you saying I'm mentally ill?

D: Of course not. It's only normal to worry about your baby.

Y: So what are you saying?

D: Two things. First, the study suggests that obsessive-compulsive disorder may happen when the same parts of the brain that help us be good parents become overactive.

Y: And second?

D: The study is also part of a growing body of research about the physiological changes that happen to people once they become parents. The question is whether people are, in some sense, pre-programmed for their roles as parents.

Y: So can I call home now?

D: Sure, Ya?l. Show's over.