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New brain study sheds light on a key component in the process of learning new skills. SCIENCE PHOTO LIBRARY/Getty Images
  • Practice sessions involving practice bouts interspersed with breaks improve motor skill learning more effectively than continuous sessions.
  • A new study used brain scans to investigate how taking breaks from a practice session can improve motor performance.
  • The study found that the brain regions involved in performing the motor task reactivated during rest but at a far more rapid rate.
  • Such replays of brain activity patterns occurred multiple times during the inter-practice rest period, and their frequency had associations with improved motor performance.

The importance of practicing when learning and perfecting new skills, from simple everyday life activities to playing an instrument or sport, remains ingrained in our minds from childhood.

However, periods of rest between these activity or learning sessions also play a crucial role in improving performance.

The improvements in skill performance during rest result from memory consolidation, which means strengthening memories formed during the practice session.

Scientists previously believed that the memory consolidation necessary for skill learning occurred during rest, over hours, or days after the practice session, especially during sleep.

However, recent studies show that improved motor skills can occur even during a single practice session involving practice sessions interspersed with resting periods. This improvement is mainly due to the memory consolidation that occurs during resting periods, known as micro-offline learning, rather than during the practice bouts.

Learning a complex skill, such as playing a song on the piano, involves forming memories that integrate multiple simple actions, such as pressing a particular key, in a specific sequence.

Until recently, scientists did not completely understand the mechanism underlying the wakeful formation and consolidation of memories involved in learning complex motor skills.

Memory consolidation during sleep is known to occur through neural replay. Neural replay involves strengthening memories by activating the brain regions at rest in the same sequence required to perform the activity or learn a skill.

Researchers at the National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institute of Health, have shown that neural replay events occur during rest periods between practice sessions and have associations with performance improvement during skill learning.

Highlighting the significance of the study, the lead author Dr. Leonardo G. Cohen, notes, “This is the first demonstration of wakeful neural replay of a newly learned skill elicited by practice in humans.”

“This study is also the first to show that wakeful replay predicts rapid consolidation of skill, which is responsible for early learning.”

The study’s findings appear in the journal Cell Reports.

The scientists recruited 33 right-handed participants and instructed them to repeat a novel typing skill with their left hand. This involved accurately typing the sequence “41324” on a computer screen as many times as possible over multiple 10-second practice bouts.

The practice session lasted 12 minutes, involving 36 10-second practice bouts, each separated by a 10-second break.

The scientists used magnetoencephalography (MEG), a highly sensitive brain-scanning technique, to record the participant’s brain activity during the entire training session. They also recorded brain activity 5 minutes before and after the training session.

The scientists found that most of the improvement in the typing task occurred by the end of the first 11 practice bouts. This improvement was primarily due to micro-offline gains observed during the 10-second resting intervals rather than the practice bouts.

During these resting intervals, the brain scans revealed neural replay events in a specific brain network involving the mediotemporal and the sensorimotor cortex.

The mediotemporal cortex includes the hippocampus and entorhinal cortex, which help encode memories of abstract information.

The sensorimotor cortex includes brain regions involved in processing sensory information and planning and executing movements.

The authors speculate that neural replay events involving the hippocampus and sensorimotor cortex could help consolidate the memory of a complex skill, integrating memories related to abstract knowledge and the planning and execution of a motor task.

“The strong involvement of hippocampal and mediotemporal activity in [the] replay of a procedural motor memory was surprising, given that this type of memory is often thought of as not requiring hippocampal contributions,” notes the study’s first author, Dr. Ethan Buch.

The reactivation of these brain regions occurred 20 times faster than their activation during the actual performance of the typing task.

Furthermore, these neural replays occurred more frequently during the resting intervals of the training session than in the 5 minutes before and after training. The frequency of these neural replay events during resting intervals had correlations with the magnitude of improvement in task performance.

The authors conclude that the rapid and recurring neural replay events could reinforce the coordination among brain regions involved while practicing the skill, resulting in consolidation of memories and improved motor performance.

The authors recognize that their study did not establish causality. They caution that “while the correlation between replay of the trained sequence and micro-offline learning is strongly suggestive of a direct contribution to [the] consolidation of skill, causality remains to be established in either animals or humans.”

In subsequent studies, the authors intend to investigate the causal role of neural replay events in improving motor learning using non-invasive brain stimulation techniques to enhance or disrupt neural replay events.

“In the end, understanding features of wakeful replay important for skill learning could lead to the optimization of therapy schedules or identification of better brain stimulation strategies aimed at enhancing rehabilitation outcomes after brain lesions like stroke,” states Dr. Cohen.