A baby’s brain is a thirsty sponge, slurping up words, figuring out faces and learning which foods are good and bad to eat. Information about the world flooding into a young brain begins to carve out traces, like rushing water over soft limestone.
As the outside world sculpts the growing brain, important connections between nerve cells become strong rivers, while smaller unused tributaries quietly disappear.
In time, these brain connections crystallize, forming indelible patterns etched into marble. Impressionable brain systems that allowed a child to easily learn a language, for instance, go away, abandoned for the speed and strength that come with rigidity.
In a fully set brain, signals fly around effortlessly, making commonplace tasks short work. A master of efficiency, the adult brain loses the exuberance of childhood.
But the adult brain need not remain in this petrified state. In a feat of neural alchemy, the brain can morph from marble back to limestone.
The potential for this metamorphosis has galvanized scientists, who now talk about a mind with the power to remake itself. In the last few years, researchers have found ways to soften the stone, recapturing some of the lost magic of a young brain.
“There’s been a very, very significant change,” says Richard Davidson of the University of Wisconsin–Madison. “I don’t think the import of that basic fact has fully expressed itself.”
Lifting neural constraints could turn back time, making way for youthful flexibility...