Here, collect nightmares.
Background introduction:
After falling asleep, human sleep changes orderly and continuously between two different sleep states. These two sleep states are called: non-rapid eye movement sleep (NREM sleep) and rapid eye movement sleep (REM sleep).
Characteristics of REM sleep include:
1. The skeletal muscles of the whole body are completely relaxed, and the limbs and body cannot move. However, there are exceptions, such as digestive tract muscles and respiratory muscles that remain active.
2. The cerebral cortex is active in thinking. If you are awakened at this time, you will often clearly feel that you have just been dreaming with a plot.
3. The sleeper's eyeballs are active during this stage of sleep, and others can observe the eyeballs shaking back and forth under the eyelids, hence the name "rapid eye movement sleep".
Precisely because the skeletal muscles are completely relaxed, the content of the dream is not expressed.
For example, if a person dreams of skiing and accidentally falls, the various actions he makes in the dream to prevent the fall will not be reflected in reality.
Purpose: Nightmare collection.