Doctors from the University of Lausanne have denied the connection between the depth of sleep and the waves of brain activity 
the connection between the depth of sleep and the waves of brain activity, writes Medical Xpress.
They dispelled the myth that with slow waves of brain activity, a person is immersed in deep sleep. For a long time, doctors believed that it was possible to determine the depth of sleep by observing brain waves using electroencephalogram (EEG) readings.
In the course of the study, experts examined data from ten patients with insomnia and 20 people with good sleep. Scientists repeatedly woke volunteers to get instant feedback and track the quality of sleep at different stages.
In insomnia sufferers, tests have shown a match between sleep with both slow brain waves and fast ones. This suggests that they were awake and asleep at the same time. According to experts, this disproves the notion that slow waves necessarily indicate deep sleep.
They also found that people without sleep problems experienced the lightest sleep during the first two hours. It also found that people with insomnia often sleep when they think they are awake. Thus, they sleep more than they think.
Earlier, Russian scientists have created a technology that records and recreates dreams using a neuro-headset.