Deep Sleep Reinforces the Learning of New Motor Skills

The benefits of a good night’s sleep have become widely known, and now neuroscientists at UC San Francisco have discovered that the animal brain reinforces motor skills during deep sleep.

During non-REM sleep, slow brain waves bolster neural touchpoints that are directly related to a task that was newly learned while awake, while weakening neural links that are not, the researchers found.“This phenomenon may be related to the notion of ‘extracting the gist’ of how to perform a novel task,” said Karunesh Ganguly, MD, PhD, associate professor of neurology. “Sleep appears to reduce neural activity that is not related to a task we are in the process of learning.”Having a better handle on the mechanics of how sleep affects learning could lead to new medical stimulation devices, and consumer-driven wearable devices, or “electroceuticals,” which stimulate brain cells and improve learning as we snooze.

Devices from some startups are headed in that direction, but so far they are designed to stimulate the brain while we are awake.

Mind Control

Ganguly’s team used a system known as a brain-machine interface (BMI) to better understand how the brain picks up new skills during sleep.The researchers implanted electrodes in the motor region of rats’ brains to send electrical signals to a computer, which then drove movement of a detached mechanical device. Because neural circuits are dynamic, the rats’ brains rewired themselves to control this device just as swiftly as they would have if the rats were practicing new ways to control their own limbs.

“People think of BMIs or neuroprosthetics as a way for the disabled to walk again or to control robotic arms,” said Tanuj Gulati, PhD, a postdoctoral scholar and lead author of the new study. “While that is the ultimate goal, we are also using them to understand the learning process in the brain.”By using such devices, experimenters can create novel causal relationships between a neuron and any desired outcome.“A particular neuron may normally be devoted to controlling a limb, but we can create a new relationship of that neuron with an external disembodied device,” Gulati said.