In a study of healthy volunteers, researchers at the National Institutes of Health mapped the brain activity that occurs when we learn a new skill, such as playing a new song on the piano, and found out why to take short breaks from practice. is the key to learning. . The researchers found that during rest, the volunteers’ brains quickly and repeatedly replay faster versions of the activity observed as they practiced typing a code. The more a volunteer replayed the activity, the better they performed in subsequent training sessions, suggesting that rest reinforced memories.
“Our results support the idea that awake rest plays just as important a role as practice in learning a new skill. It appears to be the period when our brains compress and consolidate memories of what we are doing. just practiced, “said Leonardo G. Cohen, MD, senior researcher at NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and lead author of the study published in Cell reports. “Understanding this role of neural proofreading can not only help shape how we learn new skills, but also how we help patients recover skills lost after a neurological injury like stroke. “
The study was conducted at the NIH Clinical Center. Dr Cohen’s team used a highly sensitive scanning technique, called magnetoencephalography, to record the brain waves of 33 healthy right-handed volunteers as they learned to type a five-digit test code with their left hands. Subjects were seated in a chair and under the long tapered hood of the scanner. An experiment began when a subject was shown the code “41234” on a screen and asked to type it as many times as possible for 10 seconds, then pause for 10 seconds. Subjects were asked to repeat this cycle of alternating workouts and rest a total of 35 times.
In the first few trials, the speed at which subjects correctly typed the code improved dramatically, then leveled off around the 11th cycle. In a previous study, led by former NIH postdoctoral fellow Marlene Bönstrup, MD, Dr. Cohen’s team showed that most of these gains occurred during short rests, not when subjects were resting. type. In addition, the gains were greater than those obtained after a night’s sleep and were correlated with a decrease in the size of brain waves, called beta rhythms. In this new report, the researchers looked for something different in the subjects’ brain waves.
“We wanted to explore the mechanisms behind the memory enhancement observed during awake rest. Several forms of memory seem to rely on replaying neural activity, so we decided to test this idea for learning procedural skills,” said Ethan R. Buch, Ph .D., a member of the scientific staff of Dr. Cohen’s team and leader of the study.
To do this, Leonardo Claudino, Ph.D., a former postdoctoral fellow in Dr Cohen’s lab, helped Dr Buch develop a computer program that enabled the team to decipher brainwave activity associated with entering each number in the test code.
The program helped them discover that a much faster – about 20 times faster – version of brain activity seen during typing was replayed during periods of rest. During the first eleven practice trials, these compressed versions of the activity were replayed several times – about 25 times – per rest period. This was two to three times more often than the activity observed during subsequent rest periods or after the end of the experiments.
Interestingly, they found that the repetition rate during rest predicted the strengthening of memory. In other words, subjects whose brains replayed the typing activity more often showed greater jumps in performance after each try than those who replayed it less often.
“At the start of the learning curve, we saw that the repetition of awake rest was time compressed, frequent, and was a good predictor of the variability in learning a new skill between individuals,” said Dr Buch. “This suggests that during awake rest, the brain binds memories necessary for learning a new skill.”
As expected, the team found that replay activity often occurs in sensorimotor regions of the brain, which are responsible for controlling movement. However, they also found activity in other areas of the brain, namely the hippocampus and the entorhinal cortex.
“We were a little surprised by these latest findings. Traditionally, it was thought that the hippocampus and entorhinal cortex might not play such an important role in procedural memory. In contrast, our results suggest that these regions chatter quickly with the sensorimotor cortex when learning these types of skills, ”said Dr. Cohen.“ Overall, our results support the idea that manipulating replay activity during awake rest can be a powerful tool that researchers can use to help individuals learn new skills faster and potentially facilitate stroke rehabilitation. “