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Try this: clear your mind. Try to think of absolutely nothing.

I'll wait. Not too easy, is it? You probably thought about something, even if it was “clear your mind, clear your mind, clear your mind!” That's normal.

In fact, it's not only normal, it's how you're wired. Thanks to a group of structures called the ​default mode network​, your brain is always on, even when it's not. Luckily, once you know how it works, you can find ways to control it.

We've known that the brain never really goes quiet since at least the early 20th century. Scientists back then actually discovered it by accident. In studies, they'd ask people to perform mental tasks while their brain activity was monitored.

Between tasks, the participants were asked to rest quietly. That would give the scientists a baseline level of their brain activity. Weirdly, when the participants were resting, their brain activity didn't calm down.

In fact, in certain brain regions, it increased. For the most part, scientists just treated this as a bizarre quirk and never really studied it on its own. That is, until the 1970s, when Swedish brain physiologist.

David Ingvar came on the scene. Starting in 1974, he began compiling a bunch of imaging results from studies that had measured the blood flow in people's brains when they were at rest. They let him see that specific brain regions were turning on when active thinking turned off.

One main area he noticed was the frontal lobe, which plays a big role in memory. Fast-forward to now, and more advanced technology has let scientists identify regions that turn on all over the brain — not just in the memory center, but also in areas that play a role in planning, language, social cues, and even consciousness as a whole. Since these regions are active when the brain is in its default mode — that is, when you're not consciously thinking about anything — scientists called them the “default mode network.” Researchers have also studied exactly what's going on when the default mode network is active by having people rest quietly and periodically asking them what they're thinking. “Whatcha thinkin' ‘bout?” “Nothin'.

Just default mode stuff.” They found that across the board, the brain at rest conjured up mental images, reminisced about past experiences, and made plans for the future. When you're sitting quietly and suddenly come up with the perfect comeback for a week-old insult or start imagining what's gonna happen during your upcoming trip to Iceland, that's the default mode network at play. But just because it's normal for your mind to wander doesn't mean that it's always good.

On the one hand, the mind-wandering that happens when the default mode network is active is found to play a big role in creative problem solving. On the other hand, that same mind-wandering can also involve rumination and obsessive thoughts. In fact, people with depression and obsessive-compulsive disorders tend to have stronger connections between the brain regions of the default mode network.

And even without that, it's obviously no good if your mind wanders while you're trying to concentrate on a test or pay attention to what your boss is telling you. So how do you control your default mode network? There's one strategy that's shown a lot of promise: meditation.

Specifically, something called focused-attention meditation. For a 2012 study, meditators were asked to focus on their breath while scientists scanned their brains. Every time they caught their minds wandering, the participants would hit a button.

Then they'd simply redirect their attention to their breath. Pressing a button meant scientists could look at exactly what was happening in their brains before, during, and after the meditators noticed their minds wandering. They found that, sure enough, when the meditators' minds started to wander, the default mode network lit up.

When they became aware of it, brain regions responsible for detecting important events took over. Then, when they regained focus, the ​executive network, ​which handles cognitive control, came back online. This all happened in a matter of seconds, and the most experienced meditators did it the fastest.

Like a lot of brain-imaging experiments, this was a small study. But follow-up experiments have backed up some of the same ideas. For example, researchers have found that experienced meditators have stronger connections between the default mode network and the areas responsible for attention.

Your brain always wants to be focused on something. It's just a matter of redirecting that focus to something calm and quiet so it's not so noisy up there. And the more you practice redirecting your attention, the better you'll be at it.

There's nothing wrong with the default mode network letting your mind wander. The key is not to let it be the boss of you. Thanks for watching this episode of SciShow Psych!

If you're looking for something to redirect your attention and clear your mind a bit, hopefully this video helped. And if not, we have lots of other videos you can watch! The support of our Patreon community is what has allowed us to create all of these videos as free resources for anyone who wants to learn.

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