Imagine that you learn how to play a musical instrument and you've practiced all day. You go to bed soon after and then wake up the next morning to practice and find that you remember everything that you'd learned last night. Have you ever wondered how this takes place?
A new study helps to explain what happens in your brain during those fateful, restful hours when motor learning takes hold.
"The mechanisms of memory consolidations regarding motor memory learning were still uncertain until now," Masako Tamaki, a postdoctoral researcher at Brown University and lead author of the study, said.
"We were trying to figure out which part of the brain is doing what during sleep, independent of what goes on during wakefulness. We were trying to figure out the specific role of sleep," the researcher said.
In part because it employed three different kinds of brain scans, the research is the first to precisely quantify changes among certain brainwaves and the exact location of that changed brain activity in subjects as they slept after learning a sequential finger-tapping task.
The task was a sequence of key punches that is cognitively akin to typing or playing the piano.
Specifically, the results of complex experiments performed at Massachusetts General Hospital and then analyzed at Brown, show that the improved speed and accuracy volunteers showed on the task after a few hours sleep was significantly associated with changes in fast-sigma and delta brainwave oscillations in their supplementary motor area (SMA), a region on the top-middle of the brain.
These specific brainwave changes in the SMA occurred during a particular phase of sleep known as "slow-wave" sleep.
Scientists have shown that sleep improves many kinds of learning, including the kind of sequential finger-tapping motor tasks addressed in the study, but they haven't been sure about why or how.
It's an intensive activity for the brain to consolidate learning and so the brain may benefit from sleep perhaps because more energy is available or because distractions and new inputs are fewer, study corresponding author Yuka Sasaki, a research associate professor in Brown's Department of Cognitive, Linguistic and Psychological Sciences, said.
The study is set to be published in the Journal of Neuroscience.