by University of Copenhagen

Pioneering research into the brain’s capacity to learn could unlock new understandings of brain function and provide new avenues for motor training and rehabilitation. Credit: Jakob Helbig for University of Copenhagen

Researchers at the University of Copenhagen have demonstrated that the brain’s ability to learn certain skills can be significantly enhanced if both the brain and nervous system are primed by carefully-calibrated, precisely-timed electrical and magnetic stimulations. This new research has the potential to open entirely new perspectives in rehabilitation and possibly elite sports.

Scientists meticulously calculate the process. First, electricity is delivered to a nerve in the forearm of a test subject. Milliseconds later, magnetic stimulation is applied to the motor area of their brain using a coil placed on their head. The immediate effect is visible as small, involuntary twitches in the subject’s hand. Ten seconds later, the process is repeated.

While this may evoke images of Dr. Frankenstein at work, the reality is that of pioneering research into the brain’s capacity to learn that could unlock new understandings of brain function and provide new avenues for motor training and rehabilitation. The young, healthy test subjects reportedly felt almost nothing during the process, but displayed enhanced benefits from their motor training session thereafter.

“The goal of the stimulation is to influence spinal cord networks from two sides using electrical impulses. When done repeatedly and timed precisely, the network’s efficiency can be increased. Our new findings show that this can also enhance people’s abilities to learn motor skills afterward. That’s what our research demonstrates,” explains Jonas Rud Bjørndal, a Ph.D. from the Department of Nutrition, Exercise, and Sports and one of the study’s lead researchers.

In the study by Bjørndal, Jesper Lundbye-Jensen and their colleagues, now published in Nature Communications, test subjects were shown to be able to enhance their training outcomes and boost their performance of motor tasks by up to 30% after receiving a stimulation prior to training.

On average, participants improved their abilities by about 20% with training alone, making the stimulation-induced gains significant. The research involved a series of four experiments using so-called paired stimulations of the brain and peripheral nerves.

But Jesper Lundbye-Jensen, an associate professor and head of the Movement and Neuroscience Section at the Department of Nutrition, Exercise, and Sports, cautions that this is no miracle method:

“You won’t get better at something—or become a champion javelin thrower—just by having weak currents sent through your nervous system. That probably comes as no surprise. But our research does show that combining stimulation with subsequent training can significantly enhance the benefits of one’s training, potentially making it a major help along the way.”

Brain plasticity is the key to learning

When learning motor-intensive tasks, whether it’s moving one’s fingers as quickly as possible—as in the study—playing guitar, or throwing a javelin, the brain must be able to physically change with practice. This is possible due to its plasticity.

Experiment I: Effects of paired corticomotoneuronal stimulations (PCMS) and rest on ballistic motor learning and corticospinal excitability. Credit: Nature Communications (2024). DOI: 10.1038/s41467-024-49478-5

“The brain and central nervous system networks must be able to physically adapt because that’s how we learn. These changes in the nervous system are also essential for memory, allowing us to retain and recall what we’ve learned,” explains Lundbye-Jensen.

The new study builds on previous research showing that brain plasticity can be positively influenced by stimulation of the brain and peripheral nerves e.g. through the forearm. The researchers have succeeded in demonstrating that, with precise settings and timing, this plasticity—and a readiness to learn—can be enhanced with such repeatedly paired electrical and magnetic stimulations which collide in the spinal cord.

“Since we and others have shown in earlier studies that the ability to learn motor skills is linked to plastic changes in the nervous system, it was a logical step to explore whether these two factors could have a combined effect. Our findings demonstrate that there is indeed a significant benefit,” says Bjørndal.

The researchers emphasize the importance of precise timing for the paired stimulations as a critical contribution to the field. Should the timing of the stimulations be off, the effect is much less pronounced.

“This makes the method more challenging to apply, but it aligns with our knowledge of the mechanisms involved in brain plasticity—that precisely timed, repeated activations can contribute to strengthening nervous system connections. What’s new here is that subsequent training can leverage the effects that the stimulation creates in the nervous system. This knowledge is fundamentally interesting and will be exciting to expand upon in future research,” Bjørndal adds.

New perspectives for rehabilitation—and perhaps elite sports

The findings provide fresh insight into the relationship between brain plasticity and the effects of motor training. While the extent to which this knowledge will help people improve motor function remains uncertain, the researchers hope that their results benefit society.

Initially, the technique could open new possibilities for rehabilitation strategies used in physiotherapy, health care and eldercare.

“There are people in our society who, due to nervous system injuries, for example, face steep uphill battles to regain mobility. Obviously, training is essential. But if new methods—including our research, in the long run—can make this training more effective, even by a small margin, it would be extremely satisfying,” says Lundbye-Jensen.

Additionally, stimulation techniques could also prove beneficial to elite athletes, particularly in disciplines that involve ballistic movements which are reliant upon explosive muscle power. However, anyone eager to test these experimental methods to boost their own training may find it challenging to access the equipment, which is currently limited to university and hospital researchers and staff.

More information: Jonas Rud Bjørndal et al, Hebbian priming of human motor learning, Nature Communications (2024). DOI: 10.1038/s41467-024-49478-5

Journal information:Nature Communications

Provided by University of Copenhagen

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