One year in college, just before finals, Judah Pollack decided to take up juggling. He grabbed three mandarin oranges—having thought twice about eggs—and started tossing them in the air. Never mind that he'd never juggled before or even shown an aptitude for circus tricks of any sort.
Little by little, Pollack got pretty good—not clown school good, but good enough to entertain his niece.
As it turns out, there was a subtle but powerful relationship at work between Pollack's juggling efforts that spring and his performance on his finals—all thanks to a property known to brain scientists as "plasticity."
Plasticity is the brain's ability to change its physical structure due to new experiences. When you learn or experience something new—even when you have a new thought—your brain physically changes.
In fact, a 2008 study showed that learning to juggle caused an increase in gray matter in the areas tasked with processing and storing complex visual motion—after only seven days. What's more, learning a new skill alters the brain more than maintaining an old one does.
Not only does the brain physically change as a result of learning how to juggle, the study found, but each new trick you learn changes your brain's structure even more. The same is true of learning a new language or learning to fly an airplane—or imagining the world of Narnia.
One of the questions scientists are now beginning to answer is exactly how those changes happen. While you can grow new neurons in your hippocampus, most brain plasticity occurs when neurons connect to each other in new ways. Imagine a troupe of trapeze artists. One flies while the other catches. Now imagine if every trapeze flyer had differently shaped hands. In order for the catcher to catch more than just one of the fliers, she'd need to grow new hands shaped for each one of the new fliers who swing her way.
That's exactly what your neurons do when you learn. They grow new neurotransmitter receptors, like a new pair of hands, in order to make a new connection. And they do it in milliseconds. These new "neuro-hands" are the physical building blocks of your learning something new.
As Pollack learned to juggle, the neurons in his complex visual motion area began to create new connections with one another. The more he practiced, the more adept his brain became at building these new connections. Learning got easier because his brain was in progressively better shape. This is the neurological reality behind the old joke, "How do you get to Carnegie Hall? Practice!" The more you practice sometime, the more that experience changes your brain by creating and reinforcing neural connections.
This state of constant change is our brains' natural state. As the neuroscientist Eve Marter has pointed out, we wake up with different brains each morning.
Not only is this the mechanism for how we learn, it's also the secret to our ability to have breakthrough ideas. In order to have a flash of creative insight—to think of something you've never thought of before—you have to put two things together that you've never put together before. And the only way you can do that is if your neurons are already really good at creating new connections with one another.
Learning something new, in other words, is the only way to get your brain into the habit of building new neural connections. Imagination counts, too—in order to imagine something new, your brain still has to create new connections. Reading Game of Thrones, for instance, can likewise make your brain more plastic. Pronouncing the different names and visualizing the new landscapes and strange characters all force you to build connections you haven't yet made. Even daydreaming can increase your brain plasticity and improve the chances that you'll have a breakthrough thought.
The point is that creative ideas need newness in order to happen. But limit yourself to the same repetitive experiences, and your brain will have a much harder time forming new connections. Without learning, imagining, daydreaming, or some other form of cognitive novelty, our neurons simply fall out of that habit—making our brains physically less capable of thinking up crazy new possibilities.
As for Pollack's final exams? It's true—his juggling study breaks actually helped him out. As his brain formed new neural connections, it was also getting ready to make novel connections that would pay off on test day. Sure, Pollack still needed to study his course material—but it was while juggling that he had a clever thought about the Tenth Amendment and the powers of the federal government. That wasn't a concept covered in his political science class—which is precisely what Pollack's professor later pointed out when he gave him an A.