ZURICH — We all know sleep is good for you, not just the amount of sleep but the quality, too. While a poor night’s rest can contribute to a multitude of mental health conditions and hinder one’s ability to learn or remember events, a recent study pinpoints for the first time the link between deep sleep and learning efficiency.
The relationship between the ability to learn and one’s level of deep sleep has long been demonstrated in previous research but, researchers from the University of Zurich and the Swiss Federal Institute of Technology found the causal relationship between the two in the brain.
Scientists studied thirteen subjects — six women and seven men. They were given several different sequences of finger movements to learn throughout the day. While they slept each night during the study, the researchers monitored sleep patterns in the brain using an electroencephalography (EEG).
On the first night of the experiment, individuals were allowed to sleep soundly through the night. For the second night, however, the researchers used an acoustic stimulation during deep sleep to disrupt the part of the brain responsible for finger movements and motor function. To the subjects, their sleep felt no less impaired than the first night of restful sleep.
The researchers then studied how their subjects fared on their motor tasks after the slight deep sleep disruptions. The subjects performed well on their tasks in the morning, but as the day went on, the mistakes rose.
“In the strongly excited region of the brain, learning efficiency was saturated and could no longer be changed, which inhibited the learning of motor skills,” explains co-author Nicole Wenderoth in a university release.
Yet after a night of uninterrupted deep sleep, performance rose again.
As a control, the researchers stimulated a different area of the subjects’ brains as they slept to see how learning efficiency was affected the next day. There were no changes, however, in the participants’ ability to perform the tasks after this procedure.
The researchers explain that when you’re awake, your neural synapses capture impressions from your environment, causing them to become excited, or agitated. This excitation cannot be reset without a recovery period of deep sleep. Without a night of high-quality rest, there is no room for further excitation, and learning efficiency is compromised. Now
“We have developed a method that lets us reduce the sleep depth in a certain part of the brain and therefore prove the causal connection between deep sleep and learning efficiency,” says co-author Reto Huber.
Scientists say being able to target specific parts of the brain in sleep disruption could be a way to help treat sleep disorders like epilepsy in the future.
“Using the new method, we hope to be able to manipulate those specific brain regions that are directly connected with the disease,” says Huber.
The study’s findings were published online in May 2017 in the journal Nature Communications.