Everybody dreams every night even though we do not remember all that we dream. But nobody has yet figured out why we actually dream. Let's first try to define dreams.
In simple words dreams are experiences we have of mental images, sounds, thoughts or any feeling/sensation while we sleep. They are an internal mental process. It is also said to be an expression of what we are repressing during the time when we are awake.
Three to four times a night, we usually have a period of sleep that lasts for approximately 90 minutes called as REM (Rapid Eye Movement). It is during REM sleep that our brain is more active and it is at this time that the conditions are right for dreams that are rich in action, complexity and emotions. It is most likely that we can recall the dream, if we wake up at the end of this REM sleep.
Why do we dream? Do dreams serve any purpose? There have been various theories proposed to explain dreams but no single consensus has emerged. Let's look at some of the theories to explain why we dream.
1.Psychoanalytic Theory of Dreams by Sigmund Freud. This theory suggests that dreams are a representation of unconscious desires, thoughts and motivations that are repressed from conscious awareness. While these thoughts are not consciously expressed they find their way into our awareness via dreams.
2.Activation-synthesis model of dreaming proposed by J. Allan Hobson and Robert McClarley. According to this theory, circuits in the brain become activated during REM sleep, which causes a part of the brain involved in emotions, sensations and memories, to become active. The brain synthesizes and interprets this internal activity and attempts to find meaning in these signals, which results in dreaming. In short it suggests that dreams are interpretation of signals generated by the brain during sleep.
Some other theories of dreams:
3.One theory suggests that dreams are the result of our brains trying to interpret external stimuli during sleep. For example, the sound of someone crying/ laughing which you would have heard while you were awake may be incorporated into the content of a dream.
4.Another theory compares dreams to a computer. According to this theory, dreams serve to 'clean up' clutter from the mind, similar to the clean-up operations in a computer, refreshing the mind to prepare for the next day.
5.Yet another model proposes that dreams function as a form of psychotherapy. In this theory, the dreamer is able to make connections between different thoughts and emotions in a safe environment.
Whatever be the reason behind the dreams, we cannot stop dreaming.