Have you every tried to ignore a crying baby? It's pretty impossible, right? But have you ever wondered why we're all so quick to react to a screeching newborn, even if it's not even our own? After all, we don't rush downstairs to try to turn off someone else's car alarm in the middle of the night, do we?
Researchers at the Max Delbruck Center for Molecular Medicine in Berlin have found that the small cluster of brain cells in charge of fast, active breathing also give baby animals the ability to cry. And when infant mice are stripped of this key node, they can breathe slowly and passively, but not vigorously or animatedly. Which means that when they open their mouths to cry, nothing comes out. As a result, their mothers can't hear them and don't know they need them, so they die.
"This was an astonishing finding," study author Dr. Carmen Birchmeier explained to The New York Times. "The mother could see the pups and smell the pups, but if they didn't vocalize, it was as though they didn't exist."
This is not the first study, of course, to show that the ability to cry is crucial to infant survival. Science has previously shown that the sound of an infant's cry arouses a far quicker response in the adult brain than similarly loud noises—like the aforementioned middle-of-the-night car alarm—do.
Dr. Katherine Young, a psychologist at UCLA, along with Christine Parsons of Aarhus University in Denmark, and Morten Kringelbach of Oxford University, tracked the brain's response to the sound of an infant cry and found that within 49 thousandths of a second of a recorded cry being played, the human midbrain reacted twice as fast as it did to the other audio clips tested. The researchers also detected rapid firing in brain regions that check for whether or not a particular sound is important, and whether or not we should do something about it. Which probably explains why we go into baby alert mode the minute we hear a screaming newborn in places like restaurants and airplanes, whether it's our own baby making the commotion or not.
"When you hear a baby on a plane, you're immediately alert, even if you don't want to hear it," explained Parsons. "It's a sound that's very difficult to ignore."
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