To find out how, researchers turned to an imaging technique called magnetoencephalography, or MEG. The unique advantage of MEG is that it allows scientists to observe neural activity across the entire brain with millisecond time resolution, which is crucial for investigating very fast widespread brain dynamics.

The researchers had 30 volunteers sit inside an MEG scanner and asked them to type the sequence 41324 on a keyboard as quickly and accurately as possible for 10 seconds, then rest for 10 seconds, then repeatwhile the researchers monitored their neural activity.

What the researchers found was really quite interesting. They actually found that the brain kept replaying much faster versions of the practice activity patterns over and over again during rest. So a sequence that might take one second for fingers to type, would take just 50 milliseconds for the brain to replay. That’s an impressive 20-fold compression.

The regions most active were those involved in controlling movement and representing sequences. And the more often the brain repeated the sequence, the faster the subject improved. When the participants were beginning to learn the skill, they were initially typing about five to six repetitions of the sequence during each 10 seconds of practice. But during rest, the brain replayed about 25 repetitions of the sequence, and that’s a fivefold increase over the same amount of time.

That lightning-quick neural rehearsal supercharges learning and memory. It’s as if the brain actively exploits these rest periods to amplify the effects of practice and rapidly consolidate the skill memory. And this actually appears to be this skill-binding mechanism that we were looking for. So next time you sit down to learn something, give yourself a break—or a lot of little breaks.