How does poor sleep affect our ability to learn

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MOST of us know that a good night’s sleep is key for happiness and productivity, and that conversely, a night of poor sleep can have negative effects on our performance during the day. But a new study manages to find precisely the brain area responsible for learning new skills and shows how it can be affected by poor sleep quality.
A team of researchers from the University of Zurich (UZH) and the Swiss Federal Institute of Technology (ETH) in Zurich, both in Switzerland, set out to examine the effect of a disturbed deep sleep phase on the brain’s ability to learn new things.
More specifically, the new study – published in the journal Nature Communications – looks at the brain’s ability to change and adapt in response to the stimuli that it receives from the environment, or neuroplasticity, in the motor cortex and how it is affected by deep sleep.
The motor cortex is the brain area responsible for developing and controlling motor skills, and the deep sleep phase – also called slow-wave sleep – is key for memory formation and processing, as well as for helping the brain to restore itself after a day of activity. The study involved six women and seven men who were asked to perform motoric tasks during the day following a night of unperturbed sleep, and after a night during which their deep sleep had been disturbed.
The tasks involved learning a series of finger movements, and the researchers were able to locate precisely the brain area responsible for learning movement. Using an electroencephalogram, the researchers monitored the brain activity of the participants while they were sleeping.
On the first day of the experiment – after the first movement learning session – the participants were able to sleep without disturbance. On the second night, however, the researchers manipulated the participants’ sleep quality. They were able to focus on the motor cortex and disrupt their deep sleep, thus investigating the impact that poor sleep has on the neuroplasticity involved in practicing new movements.
The participants did not know that their deep sleep phase had been tampered with. To them, the quality of their sleep was roughly the same on both occasions. Next, the researchers evaluated the participants’ ability to learn new movements. In the morning, the subjects’ learning performance was at its highest, as expected. However, as the day progressed, they continued to make more and more mistakes.