Motor learning takes place both during the active practice of new processes and in the breaks afterward. New research shows that the consolidation of practiced sequences already begins during short interruptions of practice and can be improved by brain stimulation.
We operate our smartphones or type on a keyboard every day automatically and without thinking. But first, we had to acquire these skills through repetitive practice. Motor learning takes place both during the active practice of new processes and in the breaks following the activity. This is where what has been learned solidifies so that it can be recalled later. Jost-Julian Rumpf from the Leipzig University Hospital and Gesa Hartwigsen from the Max Planck Institute for Cognitive and Neurosciences now show that this consolidation of the practiced sequences already begins during short interruptions of practice and can be improved by brain stimulation.
When exactly does the brain "remember" a newly learned motion sequence? Previously, it was assumed that the stabilization of learned motor processes does not begin until the exercise was completed, with the stabilization continuing for several hours. However, research results suggest that knowledge of new motor processes in the brain is already stored in short breaks during practice. "We wanted to understand how relevant the so-called consolidation or perpetuation in these short pauses during practice is for later recall after several hours, and whether we can influence these processes with the help of brain stimulation," said main author Jost-Julian Rumpf explaining the research approach.
The neurologist Gesa Hartwigsen developed a study with healthy participants whose task was to type in a simple sequence of numbers on a keyboard as quickly and correctly as possible. During practice, short pauses were made after a certain amount of typed number sequences. The scientists wondered what was going on in the brain during the pauses: could it be that it was already learning “offline”?
"The idea was to use magnetic stimulation through the skull to specifically influence the motor cortex only during the short pauses between the individual exercise units," reports Gesa Hartwigsen. It turned out that the brain stimulation during the breaks had improved the recall of the learned sequence of numbers six hours later. Although the participants had stopped practicing during the six-hour break, the brain processed the acquired sequences more effectively after the exercise unit and created a more stable memory track.
The researchers were also able to observe a so-called "transfer effect" from the trained hand to the other hand. "If we stimulated the brain in the pauses between the short exercise units, the trained sequence of numbers could be better recalled not only with the trained hand but also with the other hand," Hartwigsen explained. Next, the researchers want to investigate the effects of their study in older people, who, compared to younger people, often have limitations in strengthening skills after motor learning and could in the long run benefit, particularly from stimulation.
Jost-Julian Rumpf, Luca May, Christopher Fricke, Joseph Classen, Gesa Hartwigsen, Interleaving Motor Sequence Training With High-Frequency Repetitive Transcranial Magnetic Stimulation Facilitates Consolidation, Cerebral Cortex, , bhz145, https://doi.org/10.1093/cercor/bhz145