In a study of healthy volunteers, researchers mapped the brain activity that flows when we learn a new skill, like playing a new song on the piano, and discovered why taking short breaks from practice is key to learning.
Researchers from the National Institute of Health found that during the break, the brains of the volunteers rapidly and repeatedly reproduced faster versions of the observed activity while they practiced writing code. The more a volunteer repeated the activity, the better they performed during subsequent practice sessions, suggesting that the rest strengthened memories.
“Our results support the idea that awake rest plays as important a role as practice in learning a new skill. It seems to be the period when our brains compress and consolidate the memories of what we just practiced, ”said Leonardo G. Cohen, lead author of the study. “Understanding this role of neural reproduction can not only help shape how we learn new skills, but also how we help patients regain lost skills after neurological injury such as 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 sat in a chair and under the long cone-shaped lid of the scanner. An experiment began when a subject was shown the code “41234” on a screen and asked to type it in as many times as possible for 10 seconds and then take a 10-second break. Subjects were asked to repeat this cycle of alternate practices and rest sessions a total of 35 times.
During the first few tests, the speed at which the subjects correctly wrote the code improved dramatically and then leveled off around the eleventh cycle. In an earlier study, led by former NIH postdoctoral fellow Marlene Bönstrup, Dr. Cohen’s team showed that most of these gains occurred during short breaks, and not when the subjects were writing.
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 seen during awake rest. Various forms of memory appear to depend on the reproduction of neural activity, so we decided to test this idea for learning procedural skills, ”said Ethan R. Buch, a scientist on Dr. Cohen’s team and leader of the study.
To do this, Leonardo Claudino, a former postdoctoral fellow in Dr. Cohen’s lab, helped Dr. Buch develop a computer program that allowed the team to decipher the brain wave activity associated with writing each number in the code of proof.
The program helped them discover that a much faster version – about 20 times faster – of the brain activity observed during typing was reproduced during rest periods. Over the course of the first eleven practice tests, these compressed versions of the activity were repeated many 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 experiments ended, the study, published in Cell reports Explain.
Interestingly, they found that the repetition rate during rest predicted memory strengthening. In other words, the subjects whose brains repeated the typing activity more frequently showed greater jumps in performance after each test than those who repeated it less frequently.
“During the first part of the learning curve, we saw that repetition of awake rest was compressed in time, was frequent, and was a good predictor of variability in learning a new skill between individuals,” said Dr. Buch. . “This suggests that during awake rest, the brain joins the memories necessary to learn a new skill.”
Unsurprisingly, the team found that repetition activity often occurred in the sensorimotor regions of the brain, which are responsible for controlling movements. However, they also saw activity in other regions of the brain, namely the hippocampus and the entorhinal cortex.
“We were a bit surprised by these latest results. Traditionally, it was thought that the hippocampus and entorhinal cortex may not play as important a role in procedural memory.
On the contrary, our results suggest that these regions interact rapidly with the sensorimotor cortex when these types of skills are learned, ”Dr. Cohen said. “Overall, our results support the idea that manipulating repetition activity during awake rest can be a powerful tool that researchers can use to help people learn new skills faster and possibly facilitate stroke rehabilitation. “.