Practice is important for learning something new. Repeating an action over and over increases the likelihood of mastering it. But recent research shows that taking short breaks may be just as critical. A 2019 study found that short, frequent breaks were key to improving performance on a new task. These short rest periods strengthen memories of the new skill just practiced. The findings challenged the idea that only long periods of rest, like a good night’s sleep, are necessary to strengthen memories of a newly learned skill. However, it wasn’t clear how these short breaks help the brain master a new task. A research team led by Leonardo G. Cohen of NIH’s National Institute of Neurological Disorders and Stroke (NINDS) set out to understand how short periods of rest while awake aid skill learning. Their findings were published in the journal Cell Reports.
The team mapped the brain activity of 33 right-handed volunteers as they learned to type a five-digit code with their left hands. Brain waves were recorded using a sensitive scanning technique called magnetoencephalography. Participants were shown a code on a screen and asked to type it out as many times as possible for 10 seconds and then take a 10 second break. They repeated this cycle 35 times.
The team analyzed the data with a computer program they developed, which allowed them to decipher the brain wave activity associated with typing each number in the code. They discovered that a much faster version—about 20 times faster—of the brain activity seen during typing was replayed during the brief rest periods.
Over the course of the first 11 practice trials, these compressed versions of the activity were replayed about 25 times per rest period. This was 2 to 3 times more often than the activity seen during later rest periods or after the experiments had ended.
The researchers also found that participants whose brains replayed the typing activity more often showed greater jumps in performance after each trial than those who replayed it less often. Together, the findings suggest that brief rest periods serve to bind together the memories required to learn a new skill.
The team also examined the brain regions where replay occurred. As expected, replay activity often happened in the sensorimotor regions of the brain, which are responsible for controlling movements. However, they also saw activity in the hippocampus and entorhinal cortex. These regions were not previously thought to play a major role in the memories needed to perform new tasks.
“Our results support the idea that wakeful rest plays just as important a role as practice in learning a new skill,” Cohen said in a news release. “It appears to be the period when our brains compress and consolidate memories of what we just practiced. 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.”
Source: Buch ER, Claudino L, Quentin R, Bönstrup M, Cohen LG. Consolidation of human skill linked to waking hippocampo-neocortical replay. Cell Rep. 2021;35(10):109193.