What is a dream?

Dream is a kind of mental activity during sleep. The mental activity in dreams is the same as the mental activity in waking time, which is the reflection of objective things in the human brain. The bizarre dream of the dream is caused by the illusion of the stimulation of various objective things when the brain is unconscious during sleep. For example, the palpitation sensation of being chased that occurs when a person is awake with tachycardia turns into a bizarre and fearful nightmare of being chased in a dream; The palpitations caused by a person's waking bradycardia or premature beat become a strange and fearful nightmare in which the person is suspended and falling in the dream.

Dreams often feel some people are not easy to feel when awake, mild physiological symptoms, because people sleep from the outside world of various objective things of the stimulus is relatively small, from the body of various objective things of the stimulus is relatively strong caused.

Dreams are inextricably linked with people's social environment, psychological factors and physical conditions. Qian Zhongshu, in Lizi Zhang Zhan's Note to King Mu of Zhou, discussed in detail the interpretation of dreams in ancient China, and put forward that dreams can either become and 'think', or become and 'cause'. Dreaming is the so-called 'dream of the body, and the sensation in the solid body is touched into a dream.'