Over the past few years we have seen a string a studies shed light on the way we can continue to learn and form memories while we sleep. A new paper deepens our understanding of the relationship between slumber and brain function by demonstrating how sound cues during slow-wave sleep can enhance the learning of new motor skills.
The research carried out by scientists at Northwestern University has some parallels with another from the same institution we looked at in 2019. This study explored the centuries-old idea that sleeping on a complex problem can help us conjure up solutions to it, by investigating how sound cues during deep sleep could help subjects solve jigsaw puzzles.
The task of solving these puzzles was associated with individual sound cues, with the subjects then replayed some of those unique cues as they entered slow-wave sleep, or a deep sleep, during the night. This led to remarkable results, with the subjects able to solve significantly more more puzzles when they returned the next day.
The new study adapts this technique, termed targeted memory reactivation (TMR), to explore its effects on motor skills. Subjects were tasked with playing a computer game, but one that required them to move the cursor by activating specific arm muscles. Commands that moved the cursor in a certain direction were paired with unique sound cues, with the participants then made to play the game blindfolded, shifting the cursor by using only the sounds as cues.
Once the testing and training was completed, the subjects then took a 90-minute nap, with the scientists scientists playing half of the sound cues during a slow-wave sleep phase. This was designed to reactivate motor memories associated with each cue, and it appeared to have the desired effect.
Following their nap, the subjects performed far better when it came to the tasks corresponding with the sound cues played during their sleep. This meant moving the cursor far more quickly and more directly towards the target, and the subjects activated fewer superfluous arm muscles in the process.
According to the scientists, these results show that TMR during sleep can contribute to the learning of new motor skills, and they conclude that sleep can support the development of novel actions. This could have value in neurorehabilitation, helping the recovery of stroke patients, for example, or in other types of therapy.
The research was published in the journal JNeurosci.
Source: Society for Neuroscience via EurekAlert
