Answer
During sleep, a number of phases are distinguished that have to do with the depth of sleep. In addition, there is also a phase called REM (Rapid Eye Movement). This phase is characterized by eye movements and a brain pattern that closely resembles what we are awake in. During the night, a person will go through a sleep cycle 4 to 5 times, going from superficial sleep to deep sleep and back. Whenever one returns to superficial sleep, the REM periods set in. If people are awakened during the phase, they usually (about 80% of the cases) report dreams. About 25% of the sleep time is spent in REM sleep. So, on average you see several dreams per night.
Answered by
Dr Hugo Schouppe
Psychology: function theory (perception, memory, attention)

http://www.thomasmore.be
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