what happens in our brain when we sleep ?
397016
complete hell and perfect understanding
9047
Sometimes what happens is that when your sleep, the idea you have in your sleep seems a lot better than it does if you have it when you are more coherent.  The people in the bar get better-looking when you've had a few drinks; the ideas in your head seem better when you are half-asleep.
1174615
i think its because were on another level of consciousness when we are sleeping so it gets foggy to us when we wake up. one trick i have read is to write down the details of your dreams in a notebook or journal first thing when you wake up because thats when its fresh in your mind.
146466
Dreams are you subconcious mind "playing" while you sleep. You dream about what is troubling you, you dream about things that you have seen or heard, you dream about what it is that you want or need in life, and dreams seem to be a bit off or goofy, BUT they can help you and answer your questions . THink about dreams that you have had, write them down if you can remember them,what did you see, how did you feel, who was in the dream. And then write down everything that goes on in your life, your needs, your desires, your goals and those dreams will start making sense and MAYBE they have answered your questions.
61534
During your REM period of sleep ( you'll have on average 5 of these that progressively get longer as the night goes on), you will do most (not necessarily all) of your dreaming. The neurotransmitter that kicks this off is acetylcholine. It starts an action in the Pons region of your brainstem, that electrical impulse then head to the geniculate nucleus of the thalamus, and then on to the occipital lobe of the cortex (the visual center). This electrical impulse is refered to as a PGO spike. The involvement of the occipital cortex is what is creating the visual aspect of the dream, and there are a lot of theories as to what may be driving the content (loose thoughts of the day, memories old and new, prophecy, etc). The most popular theory of why you dream is the Long Term Potentiation effect by Francis Crick. He theorizes that during this time you are consolidating short term to long term memory and wiping the short term clean in order to prepare for the next day...its a common learning theory attatched to dreams.
547423
dream can simply be defined as a  series of images, ideas, emotions, and sensations occurring involuntarily in the mind during certain stages of sleep. .Dreams do not need light or any other medium to produce images...In psychology there is what we refer to as REM Sleep...Dreams occur when we undergo what we refer to as REM Sleep...REM Sleep can simply be defined as a state of sleep that recurs cyclically several times during a normal period of sleep and that is characterized by increased neuronal activity of the forebrain and midbrain, by depressed muscle tone, and especially in humans by dreaming, rapid eye movements, and vascular congestion of the sex organs -- called also paradoxical sleep, rapid eye movement sleep..Our mind stores images like a computer...We retrieve these images when we undergo REM Sleep(Rapid Eye Movement)...Now...You will say that we do not dream all what we see...This is where your subconcious mind comes in...What your subconscious mind stores is also a part of what you dream...Your subconscious mind is that part of your mind that you are not aware of..You can also say it is that part of the mind that exists but not immediately available to consciousness.When U dream scary dreams,the part of your mind that produces those dreams is the subconcious mind.Your subconcious mind stores your fears and many other aspect of your feelings...Has this been able to decipher the mystery of dreams a bit?
440933
You are your brain, but your brain is doing a huge number of things at once.  So while it has entered an altered state called "sleep", it's still quite busy, and not completely unresponsive.  It's not just dreaming, but still maintaining your body and processing incoming signals: you can ignore a loud truck on the freeway but still wake up when your child calls your name from the other room.  Or if your bladder commands you to......
540026
DREAMS\n\nAll of us have experienced "dreams". Sometimes they are good other times they are bad (nightmares), while in still others they are just confusing. I have seen many dreams, and actually do not remember most of them. They seem very real, yet you just forget it really quickly. So exactly what are dreams?\n\nWe typically spend 2 hours a night dreaming and in 85 to 90% of REM awakenings a dream is reported (5). The REM stage has always been considered the most intriguing, not only because of its unique features in relation to the other stages, but because of its strong correlation to dreams. It has been experimented that most people who claim to see dreams are awakened from REM (2). REM sleep begins with the pons sending signals to the thalamus, which then goes on to the cerebral cortex. Signals from the pons that shut down neurons in the spinal chord is seen as the source of the limb muscle paralysis. REM's relation with the cerebral cortex is seen as the source of dreams. Some scientists say that dreams are the cortex's attempt to find meaning in the random signals it receives during REM sleep (1). \n\nAlthough it is not fully proven, it is possible to see why the pons sends signals to shut down the limb muscles. In recent years it has been discovered that the paralysis prevents us from harming ourselves by acting out our dreams. There are people with a REM sleep behavioral disorder who act out their dreams and risk hurting themselves and others (6). The opposite of this form of REM sleep behavioral disorder is kanashibari (sleep paralysis) when we our conscious but are unable to move our bodies (2).
622847
Sleep is the regular state of natural rest observed in all mammals, birds and fish. Sleep is not actually "unconsciousness," but rather, it is a natural state of rest characterized by a reduction in voluntary body movement, decreased awareness of the surroundings, an increased rate of anabolism (the synthesis of cell structures) and a decreased rate of catabolism (the breakdown of cell structures). Therefore, since consciousness is literally the awareness of the surroundings, being asleep is just an altered state of consciousness, as opposed to being unconscious. It is heavily influenced by circadian rhythms and by hormonal and environmental factors. Sleep performs a restorative function for the brain and body as evidenced by the myriad symptoms of metabolic dysfunction that result when animals are deprived of sleep.\nThe function of sleep in health and in disease is being increasingly studied in specialized sleep laboratories throughout the world. Not only insomnia, but more recently elucidated sleep disorders such as sleep apnea and narcolepsy are evaluated in such facilities. The increasing prevalence of sleep disorders is likely to be a function both of more sophisticated diagnostic tests and the disruption of the normal day-night cycle in modern societies.
511304
http://www.thetruthaboutsleep.com/insomnia-physiology.html\n\nhttp://www.ask.com/web?q=How+does+insomnia+affect+the+reticular+formation%3F&qsrc=0&o=0
1090574
To answer this question you need to understand the sleeping stages.\nMany people think of their sleeping bodies as if they were cars parked for the night--motionless, engines off, headlights dimmed. But sleep is an amazingly complex state of being. As we sleep, muscles tense and relax. Pulse, temperature and blood pressure rise and fall. Chemicals crucial for well-being course through the blood stream. The brain, like a Hollywood director, conjures up fantastic stories, complete with a plot, characters and action. \n\nYou don't simply "fall" asleep. You descend slowly through different levels. As you close your eyes and drift off, you enter the first stage of what is called quiet sleep. Your brain produces irregular, rapid waves, and muscle tension decreases. You breathe smoothly, and mundane thoughts float through your mind. If roused, you might jerk awake quickly and deny that you'd slept at all. \n\nIn stage 2 of quiet sleep, your brain waves become larger, punctuated by occasional sudden bursts of electrical activity. You've definitely crossed the border between wakefulness and sleep. If someone lifted your eyelids gently, you wouldn't waken; your eyes no longer respond to stimuli. \n\nAs you descend into stage 3, your brain waves become slower and bigger. In this state of deep slumber, your bodily functions slow down even more. Finally stepping into stage 4, you reach deepest sleep, the most profound state of unconsciousness. On an EEG (electroencephalogram), your brain waves would appear extremely large and slow. You are so "dead to the world" that a thunderstorm might not wake you. \n\nThis step-by-step journey into oblivion usually takes more than an hour. Then you begin to climb upward, moving rapidly through the same sleep stages as before, not all the way to full wakefulness but in active sleep. Because the pupils dart back and forth, this stage is called Rapid Eye Movement or REM sleep. (The four stages of quiet sleep are often referred to as non-REM or NREM sleep.) \n\nDuring REM, your brain waves resemble those of waking rather than of quiet sleep. The large muscles of your torso, arms and legs are paralyzed, although your fingers and toes may twitch. You breathe quickly and slowly, the flow of blood through your brain accelerates. REM sleep is the time of vivid dreaming, and if wakened, you'd probably recall a fragment of a fantasy. \n\nAfter about ten minutes in REM sleep, you descend the sleep staircase again. The entire cycle of REM and NREM stages takes roughly 90 minutes. Early in the night, the periods spent in the deepest stages of quiet sleep are longer. In the second half of the night, REM sleep predominates. By morning, you go around the sleep circuit four or five times. \n\nThis pattern changes gradually throughout life. From infancy to adulthood, REM periods dwindle to less than a quarter of a night's sleep. By their thirties, men spend less time in the very deep stages of NREM sleep. Women begin to sleep less deeply in their fifties. By age 65, both sexes spend half as much time in deep sleep as they did when they were 25. The lighter sleep stages increase later in life, and REM shrinks to about a fifth of total sleep time.
617178
Blood flow is not constant in the brain at all times. If you're taking an exam, your cerebrum is going to be more active than if you are just laying down and resting. \n\nIn terms of exercise, the sympathetic system kicks in...increased heart rate, pupils dilated, dilation of bronchial passages, and more blood going to certain parts of the brain to be more alert and active.
207702
inside the insomniacs brain
251051
Basically, dreams are caused by REM or Rapid Eye Movement. Brain activity changes with sleep in four different patterns, ranging from light sleep (you can be woken up at any time) to really deep sleep (a bomb couldn't wake you). It is said that REM or dreams begin from Level 3 onwards, and goes into short 10-15 minute lapses before it slows down and lowers itself to Level 2 brain activity (which is half-asleep and half-awake). It will happen over 7-8 times in a night.\n\nDreams on the other hand are basically imagination - and basic brain activity that result in images. They could be your thoughts, or your worries, or anything you make of. That's why, people usually relate dreams to the things that are happening in their life.\n\nHope this helps!
1106128
well, because when we sleep we have no control of our thoughts.\nIt's just  jumbled up pieces of our memory made into an interesting story.
494921
You want an experiment you can do? Find out what happens to your mind when you are in a deep and dreamless sleep.\n\nYou will find that there is no 'mind' to have at all. It's pretty much like asking, "What happens to the light when you turn the light switch to off?"\n\nYour mind requires a certain venue to happen. It needs oxygen and nutrients to function. Without those, there is no mind to 'have'. The switch is off.\n\nBut check it out for yourself next time you are in a deep and dreamless sleep. You should be able to not see that there is no mind there to see.
532132
Our cells do not sleep.  The function of cognizance shifts from the real world to the dream world.  Yes, as we expand our knowledge our capacity to learn increases.  It is a false notion that there is only so much "space" in the brain\nWe all function far below or mental capacities.