Why Your Brain Needs Idle Time
“Your attention may be your most precious resource, and you only have so much of it to spread around each day.
Work and social obligations demand a portion of it. And it’s easy to occupy whatever is left over with stimuli of one kind or another — whether it’s listening to a podcast or watching a show. For many people, time spent in the shower or trying to fall asleep at night may be the only remaining scraps of the day when their mind is wholly free to wander.
None of this may seem like a problem. After all, why waste time doing nothing when you could be doing something fun or productive? As long as you’re occupying your mind with (mostly) high-quality content, what’s the harm?
“The research on learning is extremely clear,” says Loren Frank, a professor at the Center for Integrative Neuroscience at the University of California, San Francisco. “To learn something well, you need to study it for a while and then take a break.”
Frank points to the evidence on educational training, which has shown again and again that people retain new information best when their minds are given time off to encode and consolidate. Even outside of study contexts, taking small breaks after digesting new material — whether it’s a news article or an important email — appears to help your brain parse and memorize what you’ve just learned.
To better understand how brains process new information, Frank has conducted brain-scan experiments on rats. He and his colleagues have shown that when rats are allowed to rest after completing an unfamiliar maze, their brains appear to automatically replay the experience of navigating the maze. Confronted later with the same labyrinth, the rats find their way through it more quickly.
“We know the brain can get into its downtime state very quickly, and the education research suggests just a few minutes — five to 15 — are enough to aid learning.”
On the other hand, when rats are immediately confronted with a new challenge after completing a maze, their brains don’t have the chance to replay what they’ve learned, Frank says. Later, when challenged again with the same maze, these rats aren’t able to navigate it any faster than they did the first time.
Frank says the human brain seems to work in a similar way. “The brain needs free time to process new information and turn it into something more permanent,” he says.
How much free time? That depends. “We know the brain can get into its downtime state very quickly, and the education research suggests just a few minutes — five to 15 — are enough to aid learning,” he says. The amount of time a mind needs to construct a durable memory probably varies from one person to the next, and also depends on the complexity of what that person is trying to learn, he adds.
Experts say idle time likely also helps develop mental processes that are far more complicated than memory storage and retrieval. “The deeper reflective states, where you make meaning of what’s going on and connect it to self and identity and integrate knowledge together into coherent narratives — these kinds of processes only happen when you’re not focused on some in-the-moment activity,” says Mary Helen Immordino-Yang, a professor of education, psychology, and neuroscience at the University of Southern California.
When your brain is bombarded with novel stimuli or information, she says, it can struggle to generate purposefulness and meaning. Too much of this can you leave you feeling aimless — or worse. “If you’re stuck in this feed-me stimulation loop, we know that this is associated with the feeling of being out of control,” she says. “It’s associated with anxiety and disconnectedness, and a feeling of, what’s really real?”
Mental idle time, meanwhile, seems to facilitate creativity and problem-solving. “Our research has found that mind-wandering may foster a particular kind of productivity,” says Jonathan Schooler, a professor of psychological and brain sciences at the University of California, Santa Barbara who has studied mind-wandering extensively. He says overcoming impasses — including what he calls “a-ha!” moments — often happen when people’s minds are free to roam.
“I think we need to recognize that the brain’s internal train of thought can be of value in itself.”
Schooler mentions the common experience of not being able to recall a word that’s on the tip of your tongue — no matter how hard you try to think of it. But as soon as you move onto another mental task, the word pops into your head. “I think it’s very possible that some unconscious processes are going on during mind-wandering, and the insights these processes produce then bubble up to the surface,” he says.
It’s also possible that depriving the brain of free time stifles its ability to complete this unconscious work. “I think we need to recognize that the brain’s internal train of thought can be of value in itself,” Schooler says. “In the same way we can experience a sleep deficit, I think we can experience a mind-wandering deficit.”
“Many people find it difficult or stressful to do absolutely nothing,” he adds. Instead, Schooler says “non-demanding” tasks that don’t require much mental engagement seem to be best at fostering “productive” mind-wandering. He mentions activities like going for a walk in a quiet place, doing the dishes, or folding laundry — chores that may occupy your hands or body but that don’t require much from your brain.
While a wandering mind can slip into some unhelpful and unhealthy states of rumination, that doesn’t mean blocking these thoughts with constant distraction is the way to go. “I think it’s about finding balance between being occupied and in the present and letting your mind wander — [and] about thinking positive thoughts and thinking about obstacles that may stand in your way,” says Schooler.
There may be no optimal amount of time you can commit to mental freedom to strike that balance. But if you feel like it takes “remarkable effort” for you to disengage from all your favorite sources of mental stimulation, that’s probably a good sign you need to give your brain more free time, Immordino-Yang says. “To just sit and think is not pleasant when your brain is trained out of practicing that, but that’s really important for well-being,” she adds.
Frank recommends starting small — maybe take a 15-minute, distraction-free walk in the middle of your day. “You might find your world changes,” he says.