LOS ANGELES - Researchers at the National Institutes of Health recently mapped out the brain activity that flows when we learn a new skill, such as playing a new song on the piano, and discovered why taking short breaks from practice may be a key to learning.
In a study published Tuesday and conducted at the NIH Clinical Center, researchers found that during rest the volunteers’ brains rapidly and repeatedly replayed faster versions of the activity seen while they practiced typing a code.
In fact, the more a volunteer replayed the activity, the better they performed during subsequent practice sessions, suggesting rest strengthened memories, according to NIH.
The 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.
According to the study’s authors, the subjects sat in a chair and were shown the code "41234" on a screen and asked to type it out as many times as possible for 10 seconds and then take a 10-second break. Subjects were asked to repeat this cycle of alternating practice and rest sessions a total of 35 times.
"Our results support the idea that wakeful 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 just practiced," said Leonardo G. Cohen, senior investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and the senior author of the study published in Cell Reports. "Understanding this role of neural replay may not only help shape how we learn new skills but also how we help patients recover skills lost after neurological injury like stroke."
During the first few trials, the speed at which subjects correctly typed the code improved dramatically and then leveled off around the 11th cycle.
Researchers also found that the frequency of replay during rest predicted memory strengthening. For example, those whose brains replayed the typing activity more often showed greater jumps in performance after each trial than those who replayed it less often.
"During the early part of the learning curve we saw that wakeful rest replay was compressed in time, frequent, and a good predictor of variability in learning a new skill across individuals," said Ethan R. Buch, a staff scientist and leader of the study. "This suggests that during wakeful rest the brain binds together the memories required to learn a new skill."
In a previous study, Cohen’s team showed that most of these gains happened during short rests, and not when the subjects were typing.
"We wanted to explore the mechanisms behind memory strengthening seen during wakeful rest. Several forms of memory appear to rely on the replaying of neural activity, so we decided to test this idea out for procedural skill learning," said Ethan R. Buch, Ph.D., a staff scientist on Dr. Cohen’s team and leader of the study.
The authors said the results suggest that regions of the brain are rapidly communicating with the sensorimotor cortex when learning these types of skills. This may result and support the idea that manipulating replay activity during waking rest may be a powerful tool that researchers can use to help individuals learn new skills faster and possibly facilitate rehabilitation from stroke.