Your thoughts wander during an unnecessary meeting that could have easily been summarized in an email.
Feel guilty? Don’t—your seemingly self-indulgent mental detour may have boosted your brain’s neuroplasticity—the brain’s ability to change and adapt due to factors like injury and learning.
Researchers at Harvard tracked brain activity in mice as they looked at two images featuring distinct checkerboard patterns. During periods of rest between images, researchers found, the mice’s thoughts would drift back to those images. How could the researchers tell? The patterns of neurons fired while the mice were daydreaming looked incredibly similar to the distinct patterns fired when each image was originally shown.
What researchers didn’t expect to find: that the slightly altered pattern of neurons fired during daydreaming would influence which neurons fired when the image was shown again, in a process they call “representational drift.” What’s more, the patterns of neurons fired for each image became increasingly distinct, until each involved an almost entirely unique set of neurons.
The findings were published Wednesday in the journal Nature.
“There’s drift in how the brain responds to the same image over time, and these early daydreams can predict where the drift is going,” senior author Mark Andermann, professor of neurobiology at Harvard Medical School, said in a news release about the study.
A learning process similar to AI
The study provides preliminary evidence that daydreams are involved in neuroplasticity.
“When you see two different images many times, it becomes important to discriminate between them,” Nghia Nguyen, a doctoral student in neurobiology at the Blavatnik Institute at Harvard Medical School, said in a news release.
The team’s findings suggest that repeated daydreaming may eventually help the brain distinguish between similar images, he added. That’s because the study’s mice seemed to “be learning more about the picture by daydreaming about it,” the team said in a joint statement provided to Fortune.
“The mouse may be incorporating this new picture into its model of the world based on all the previous pictures it’s seen—kind of like when you see a small fluffy animal on a leash in New York and then you think, ‘Was that a cat or a dog?’” the researchers explained. “Then you figure it out, and next time you look at the animal, it’s obvious what it is.”
This type of learning has its advantages, the researchers assert. In the case of mice, it could allow them to learn more about a threat, like a predator, from recalling one encounter, instead of repeatedly exposing themselves to danger. For humans, it’s simply “an efficient way to learn about the world.” AI software uses a similar process to learn about images.
What is ‘quiet wakefulness’?
The study aligns with others that have shown that entering a state of “quiet wakefulness” after an experience can boost learning and memory in both rodents and humans.
Just what is quiet wakefulness? Also known as daydreaming, it’s a state of relaxed environmental awareness that helps the mind process complex thoughts, researchers say, “when you’re awake but chilling out.”
Given the results of the study, it may be important to make time for daydreaming, in a bid to cement learning accomplished during the day, the researchers suggested. Scientists have long known that memory consolidation and knowledge updates tend to occur during sleep. But more recent work suggests that similar processes may occur during daydreaming, or even a different type of learning altogether that could be a beneficial addition to what occurs at night.
For mice, that may mean taking a pause from viewing a series of images. For humans, it might entail putting down their smartphone to allow daydreaming to occur.
“We feel pretty confident that if you never give yourself any awake downtime, you’re not going to have as many of these daydream events, which may be important for brain plasticity,” Andermann said.
