Want to Be Better at Whatever You Do? Harvard Neuroscience Says Your Sleeping Brain Has a Secret Strategy

I’m going to give away one of my big writing secrets.

When I’ve been stuck in a big narrative puzzle while writing a book, I’ve learned the trick is to clear my head and take a nap.

I’ve never really understood exactly how it works, but the sheer number of times I’ve awakened with the solution at hand—even without recalling dreaming about it—tells me there’s something there.

That’s why I was taken by a new study from Harvard Medical School and Massachusetts General Hospital that suggests something similar.

Neuroscientists there found that when people learn a new motor skill, their brains don’t just generally “consolidate” the memory during sleep. Instead, the brain sends targeted bursts of activity called sleep spindles to the exact regions that were engaged during learning.

The stronger those targeted spindles, the better people performed on the task after waking up.

Brief bursts in the right places

The study was published in The Journal of Neuroscience. Eric Dolan reported on it for PsyPost.

Sleep spindles are brief bursts of brain activity—just a second or two—during light non-REM sleep, long known to play a role in memory. But this study suggests they’re far more sophisticated than we thought.

Rather than firing randomly across your brain, these spindles concentrate in the specific cortical areas you used while learning something new.

The researchers recruited 25 healthy adults and had them come in for three separate “nap visits” (my favorite kind of visit).

During one session, participants learned a finger-tapping sequence—repeatedly typing a five-digit number with their left hand, like 4-1-3-2-4, as quickly and accurately as possible.

Then they took a 90-minute nap while the researchers monitored their brain activity using both EEG and magnetoencephalography (MEG)—two complementary imaging techniques that together can pinpoint exactly where sleep spindles fire.

A few hours later, the participants were tested again on the same finger-tapping task.

Two different kinds of improvement

About 18 percent of brain regions active during learning showed increased spindle activity during the nap. Only 3 percent of regions outside that network did.

These areas included the primary motor cortex (where hand movements are controlled), motor planning regions, and supplementary motor areas.

The study also found that learning during practice and improvement after sleep involved completely different brain regions.

When people initially learned the task, spindle increases correlated with activity in motor execution areas—the parts of the brain that control your hand movements. But improvements measured after the nap correlated with spindle activity in motor planning regions, like the supplementary motor area and premotor cortex.

The two sets of regions didn’t overlap at all.

Study lead Martin Sjøgård, a postdoctoral fellow at the MGH Martinos Center and Harvard Medical School, and his colleagues suggest this means your brain is doing two different jobs.

• During initial learning, it’s encoding the memory.
• During sleep, it’s consolidating and refining it—making the skill more automatic and less dependent on conscious attention.

Not just about finger tapping

The researchers note that because sleep spindles are measurable and can potentially be enhanced through noninvasive brain stimulation, this work might eventually lead to new treatments to boost learning—especially in people with neurodevelopmental disorders where spindles are often deficient.

And while this study focused on motor skills, as Dolan notes in PsyPost: “the authors suggest that similar principles may apply. If other types of learning also recruit spindles in specific cortical regions, then tracking these changes could provide a sensitive marker of how well the brain is consolidating new information.”

Regardless, it’s useful to understand how and why your brain processes learning and memory while you sleep, even if the specific application here is different from the kind of problems I’m usually trying to solve.

I’m left with just one big question: I wonder how many naps they took while writing the study.