Having a habit of sleeping under the TV, turning on any channel, and slowly fall asleep turns out to be harmful. You never know what the brain will remember from what was heard, as not all information is equally useful. Be careful and think about the background that surrounds you in your sleep.
Experiments conducted by researchers Ecole Normale Supérieure in Paris, showed that in the long period of non-REM sleep, we continue to unconsciously hear and understand the words. The results describe an article published in The Journal of Neuroscience.
In the dream, we almost do not react to external stimuli and are unable to move: these processes are inhibited in the brain even at “low” level. However, some triggers are able to break through that lock and get us to wake up and come back to consciousness. Perhaps, the brain retains a certain level of vigilance, tracking environmental safety conditions. This ability was studied by Kuide Sid (Sid Kouider) and his colleagues. For the experiments they selected 23 young healthy volunteers, who were sleeping in the laboratory under the supervision of the scientists. To begin with, researchers read to them different words (in the native language) and using an electroencephalogram (EEG) monitored the activity of the brain while awake. Volunteers had to press a button: with the left hand if the word meant something, and with the right if it sounded more like an animal. It was possible to establish patterns of the brain specific to each volunteer by the electrical activity associated with the movement of the left and right hands. Then, these experiments were repeated during different phases of sleep: light slow (the longest phase), deep slow and rapid REM-sleep (in during which we tend to see the dream). With the EEG it was possible to know whether the brain reacted by trying to give a hand signal, whether he understands the spoken word or not. As it turned out, in the fast sleep the brain still recognized words used on the first stage of the experiment; new words had no response from the nervous system. Also during deep REM sleep no brain activity was observed connected to the external stimuli. Scientists believe that the lack of reaction during deep REM sleep is associated with a massive “disconnect” by the neurons in the brain while at the same time in a fast sleep aroused neurons compete with the excitation caused by dreams. This weakens their response, and the activity occurs only in response to the familiar words that are easier to excite the “trained” neural network.
It should be noted that the theory of “patrol points” in the cerebral cortex, supporting wake even in sleep conditions was put forward by the Nobel Prize in physiology Ivan Petrovich Pavlov, including his experiments with hypnosis.