There are two kinds of sleep, the 'non-dreaming' sleep and the 'dreaming sleep'. During the non-dreaming sleep, the thought series are rational, slow moving, unimaginative and not particularly visual. Later on these very thoughts acquire a life of their own. As every 90 minutes the curtain rises and the dreaming sleep unfolds. This lasts for about 20 minutes. Dreams during this period are bizarre and largely based on previous waking events, that will be distributed in irrational ways.
Dreaming sleep is also known as rapid eye movement sleep (REM sleep), because the eyes are in vigorous activity similar to the awake state to look around.
During dreaming sleep our bodies and limbs try to enact the dream and move about quite violently, which can be dangerously. To prevent this, brain paralyses the body thus preventing all movements. But yep the body reacts to dream in the form of some twitching of the hand and feet and ofcourse the eye movements. Breathing and other vital functions continue normally. Suddenly when we are awoken from the dream, the paralyses continues for a while, even preventing attempts to cry out, and adding to the frightening experience. The paralysis is absent during non-dreaming sleep. Here sleep walking and sleep talking can occur, which is usually during the deepest form of non-dreaming i.e. non-REM or NREM sleep. Sleep walkers are in a world of their own, engrossed unresponsive and often they search something only known to them. They cannot be awoken and it is advisable to guide them to bed and not to wake them up.
Dreams are usually in colours but the image soon fades into black and white and in 10 minutes or so, it completely disappears unless we happen to wake up and then make a real effort to remember. Dreams are not over in a flash and it runs its full course, partly because dreaming is a light form of sleep and the sleeper is vaguely aware of his surroundings. Unless the sensation perceived is disturbing, the sleeper just dreams on.
So, why do we dream? During non-dreaming sleep, the brain probably recovers from the wear and tear of wakefulness. But probably does not like being unconscious for too long and need periodic stimulation to keep it in tune. It may well be the reason for so much REM sleep before birth, to make up for the lack of sensory stimulation to the brain for the baby in the womb.
But in the adult stage, most of the dreams are mundane, involving unknown scenery and strangery, with the scenario being an everyday scene or mishap, and the dreamer is usually participating in some way.
Dreaming sleep is also known as rapid eye movement sleep (REM sleep), because the eyes are in vigorous activity similar to the awake state to look around.
During dreaming sleep our bodies and limbs try to enact the dream and move about quite violently, which can be dangerously. To prevent this, brain paralyses the body thus preventing all movements. But yep the body reacts to dream in the form of some twitching of the hand and feet and ofcourse the eye movements. Breathing and other vital functions continue normally. Suddenly when we are awoken from the dream, the paralyses continues for a while, even preventing attempts to cry out, and adding to the frightening experience. The paralysis is absent during non-dreaming sleep. Here sleep walking and sleep talking can occur, which is usually during the deepest form of non-dreaming i.e. non-REM or NREM sleep. Sleep walkers are in a world of their own, engrossed unresponsive and often they search something only known to them. They cannot be awoken and it is advisable to guide them to bed and not to wake them up.
Dreams are usually in colours but the image soon fades into black and white and in 10 minutes or so, it completely disappears unless we happen to wake up and then make a real effort to remember. Dreams are not over in a flash and it runs its full course, partly because dreaming is a light form of sleep and the sleeper is vaguely aware of his surroundings. Unless the sensation perceived is disturbing, the sleeper just dreams on.
So, why do we dream? During non-dreaming sleep, the brain probably recovers from the wear and tear of wakefulness. But probably does not like being unconscious for too long and need periodic stimulation to keep it in tune. It may well be the reason for so much REM sleep before birth, to make up for the lack of sensory stimulation to the brain for the baby in the womb.
But in the adult stage, most of the dreams are mundane, involving unknown scenery and strangery, with the scenario being an everyday scene or mishap, and the dreamer is usually participating in some way.
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