Most of us know that a good night’s sleep is key to happiness and productivity, and that conversely, that is, a sleepless night or a few hours of sleep, can have negative effects on our performance during the day. Now, a study developed by researchers at the University of Zurich and the Swiss Federal Institute of Technology in Zurich, Switzerland, has discovered precisely how the area of the brain responsible for learning new skills can be affected by poor sleep.
The experts set out to examine the effect of a disturbed deep sleep phase on the brain’s ability, specifically the motor cortex, to learn new things. Thus, they had the participation of 6 women and 7 men who were asked to perform motor tasks during the day after a night of uninterrupted sleep and after a night during which the deep sleep phase had been altered.
Using an EEG, the researchers monitored the participants’ brain activity while they slept. On the first day of the experiment in which the participants had to learn a series of hand movements, the participants were able to sleep without discomfort. On the second night, however, the experts manipulated the participants’ sleep quality, targeting the motor cortex and disrupting their deep sleep. They then assessed the participants’ ability to learn new movements. In the morning, the subjects’ learning performance was highest, as expected. However, as the day progressed, they made more and more mistakes . Something that was also expected.
Again, after a good night’s sleep, the learning efficiency of the participants increased again. After another night of interrupted sleep, not only did their learning efficiency not improve, but the following morning, the participants’ performance was as low as the night before.
The reason this occurs, according to the authors, is that by interrupting deep sleep, the synapses of neurons do not “rest” as they normally would during restful sleep. Without this nocturnal restoration period, synapses remain highly excited for too long, which inhibits neuroplasticity, making learning new things no longer possible.
“In the highly excited region of the brain, the learning efficiency was saturated and could no longer be changed, which inhibited the learning of motor skills, ” explains Nicole Wenderoth, leader of the work.
To confirm they were altering the area of the right brain responsible for deep sleep, the researchers repeated the experiment assigning the same task but manipulating a different region of the brain. There was no change in the performance of the participants . This is the first time that a study has shown a causal relationship between deep sleep and learning efficiency.
The study has been published in the journal Nature Communications.
Source: ‘Deep sleep maintains learning efficiency of the human brain’ Article: 15405 (2017) doi: 10.1038 / ncomms15405. Nature Communications. University of Zurich (UZH) and the Swiss Federal Institute of Technology (ETH) in Zurich.
