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Thread: Why do we sleep?

  1. #1 Why do we sleep? 
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    No one knows why we sleep, but it’s certain that we need to. People who are prevented from sleeping begin to suffer obvious effects after a few days—they think less clearly, and they fall asleep during the working hours.
      There are no rules about sleep. Generally speaking, grown-ups sleep about 7 and a half hours each night and probably more than 60 percent get between seven and eight hours. But perhaps eight percent are quite happy with 5 hours or less, and four percent or so find that they want ten hours or more. If you feel all right, you’re probably getting enough sleep. The important thing is not to worry how much other people get—their needs may be different. Exercise doesn’t seem to increase the need for sleep—office workers, for example, sleep for about as long as people doing physically active work.
      Children sleep more than grown-ups—perhaps 14 to 18 hours soon after birth, going down to grown-up levels by early teenage . Sleep patterns also tend to be different in the old people, who may sleep less at night than they did when younger, find sleep getting more broken, and often make it a rule to sleep during the daytime.


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    The "Sleep Phenomenon" is far from mystery.
    One need's to rest his body and mind so the "system" won't overload. Simple.

    Btw, the exercise part is untrue. People who do exercise regularely tend
    to require less sleep than "normal people" later on when they are "veteran exercisers".

    Also, people who like to daydream usually become passive-tired(at times) type of people.

    I'm sorta middle-ish, I do intensive workout, but usually sleep through the whole day
    when I'm at school xP


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    Not that Truth is a democracy (well, it is, really), but I agree: no one knows why we sleep. Isn't that interesting?
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    Our bodies need to sleep so that our spirits can walk the night ...
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    I thought sleep was just a way to let one's body recover from the day's many adventures. It's like the time when the body refreshes itself by going on a little vacation for some hours
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    From an evolutionary point of view, it is thought sleep developed as there was no benefit to staying alert at night when there was little light or heat from the sun, but this became more than just a habit, it became physiologically essential.

    Nerve firing slows when one is asleep (except during REM sleep when there is rapid firing) which is thought to allow neurotransmitters replenish.
    It also has effects on memory, concentration as well as glucose metabolism and hormone levels of various hormones who's levels change in circadian rhythm.

    In animal models sleep deprivation causes death so it is clearly a necessary part of nervous system physiology.
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    From an evolutionary point of view, it is thought sleep developed as there was no benefit to staying alert at night when there was little light or heat from the sun, but this became more than just a habit, it became physiologically essential.
    Well, what if the early human lived in a place fraught with predators, and the human had enough common sense to realize "Oh, I'd better not fall asleep, because if i do, something will find me, drag me off, and kill me."

    Wouldn't the instinct of survival against nighttime predators be so deeply ingrained, that sleep would actually become obscure....and possibly unnecessary?

    The human would fear death, and thus stay awake at night keeping watch........and then learn to conserve his/her own energy in order to slowly ward off any drowsiness, or sleepiness............................right?
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    But that's only from a human, egocentric point of view. All animals developed this characteristic, long before humans.

    And the obvious answer is that when something happens when you're asleep, you wake up, and animals find safe places to sleep at night... birds build nests, rabbits live in tunnels and early man... had fire.

    Even predators need sleep, take the owl for example, sure its nocturnal habbits enable it to hunt at night when its easier to hunt, but it still needs to sleep by day.
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    Circadian period should be 24 hours.
    Circatidal period should be 24 hours and 50 minutes.

    Humans prefer 24 hours and 11 minutes, but environmental cues tweek it. 24:11 is a compromise between sun and tide. In other words if you're a coastal forager you will stay out a bit later each consecutive night to exploit the low tide until dark and cold make this impractical, then switch to pre-dawn waking for that same tide. The switch is easy because by the time you ought to switch, you'll be craving extra sleep (remember your foraging pattern has been keeping you awake up to 39 minutes "too long" each day). You always catch both lows that way, breakfast and dinner.

    If you're a coastal raccoon then you follow both tides too, while being "mostly nocturnal".
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    answer is simple - to repair and reheal the body
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    No, no! We need rest to repair, reheal, and rest the body - that's all. The body doesn't need sleep. However the brain/mind will die without quality sleep.
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    What if we are actually other people in a distant super tech universe using THIS life as a "fun" simulatior? Sleep is needed so the real us can wake up in our real world and do stuff.

    In the future end of evolution and technology we are immortal and straight out BORED over having it all and dont live with risks.

    So we invented this "simulator" so we can live back in this time were limited time makes our lives fun/sad... emotional... so we can feel something again.

    In a sense... we are the SIMs without knowing it. We know it only when we wake up in the real world and our memory is wiped each time we "log back in"


    ...



    ...


    I read this theory somewhere and thought it was interesting. Allthough tbh, i dont really believe it. But i like theorizing Sleep is simply needing the brain to "reboot" its the price for our intelligense?
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    yeah I have no comment about your SIM high tech idea.

    But yes in sleep there is the "eraser" model, where we process out memories from the day during sleep so that we can process new information for the next day.
    This is about as far as we need it for our intelligence.

    And what do you mean by "reboot". Everyone in this thread has given what they feel to be a scientific answer which is really a vague notion that we would all have from needing sleep outrselves.
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    Having a proper of Sleep is beneficial to the immune system, memory, and lets not forget the skin. The production of protein during sleep helps with cell growth which in effect of the whole body.
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    I do think that "we don't know why we sleep".

    All the logical and folk-plausible explanations are just that.


    The evolutionary "night time 'off-mode' explanation (which I Favour) too.


    But we really don't know why we sleep.
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    I remember sleep deprivation studies which indicate there is no benefit to the body for sleep beyond just being sedentary. That is, as far as the body is concerned, sleep and just lying still for 8 hours are the same thing.

    Human subjects deprived of sleep have little degradation in muscle strength or endurance. It's reflexes and rational thinking which degrade from lack of sleep. Indicating that sleep isn't for the body at all, it's for the mind. For some reason our brains require significant down time every day in order to function properly. Given the strong evolutionary advantage to a human needing even ten minutes less sleep a night, we can assume that sleeping is highly necessary, and highly efficient at whatever it does.

    It's way more necessary than food, since we can go without food for days and days. That means that saving metabolism isn't the issue here. If it was, one would assume that people could go weeks without sleep. Sleep seems to be only slightly less necessary to function than water. An ordinary person will die within days without water, while people can go that long without sleep in times of extreme need. But not by much. World record is something like 11 days.
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    Quote Originally Posted by Numsgil
    I remember sleep deprivation studies which indicate there is no benefit to the body for sleep beyond just being sedentary. That is, as far as the body is concerned, sleep and just lying still for 8 hours are the same thing.
    Not really. What about fatal familial insomnia?


    http://www.youtube.com/watch?v=Co94aQDs3ek
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    Quote Originally Posted by Numsgil
    Given the strong evolutionary advantage to a human needing even ten minutes less sleep a night, we can assume that sleeping is highly necessary, and highly efficient at whatever it does.
    I hadn't thought about it that way before. Thanks. :-D
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    Quote Originally Posted by gottspieler
    Quote Originally Posted by Numsgil
    I remember sleep deprivation studies which indicate there is no benefit to the body for sleep beyond just being sedentary. That is, as far as the body is concerned, sleep and just lying still for 8 hours are the same thing.
    Not really. What about fatal familial insomnia?


    http://www.youtube.com/watch?v=Co94aQDs3ek
    The brain regulates many of the body functions. In all probability the higher brain functions (rational thought, etc.) shut down first after a person has been deprived of sleep for a few hours. As the sleep deprivation continues, it continues on down to the mammalian and finally reptilian brains, until it starts to interfere with basic motor functions and autonomic functions. My guess is that the body itself is still mostly functional, but it's being "sabotaged" by a faulty central nervous system.

    Still it's pretty hard to separate the effects on the brain from the effects on the body like this... So we just have to go on sleep deprivation studies where we can chart a person's destructive slide and try to make inferences from the data.
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    Quote Originally Posted by Numsgil
    Quote Originally Posted by gottspieler
    Quote Originally Posted by Numsgil
    I remember sleep deprivation studies which indicate there is no benefit to the body for sleep beyond just being sedentary. That is, as far as the body is concerned, sleep and just lying still for 8 hours are the same thing.
    Not really. What about fatal familial insomnia?


    http://www.youtube.com/watch?v=Co94aQDs3ek
    The brain regulates many of the body functions. In all probability the higher brain functions (rational thought, etc.) shut down first after a person has been deprived of sleep for a few hours. As the sleep deprivation continues, it continues on down to the mammalian and finally reptilian brains, until it starts to interfere with basic motor functions and autonomic functions. My guess is that the body itself is still mostly functional, but it's being "sabotaged" by a faulty central nervous system.
    Interesting theory. However, it is wrong. In the disorder I mentioned above, An insoluble protein causes plaques containing aggregates of PrPsc (a prion) to develop in the thalamus, a region of the brain responsible for regulation of sleep. This first results in insomnia, and then progresses to more serious problems over time. Therefore the thalamus, a part of the limbic system, is affected primarily.
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    Well, it does complicate matters slightly since the root cause of the sleep deprivation is so low level in the reptilian brain. The early symptoms like phobias and panic attacks are probably sister symptoms with the insomnia.

    And since in my hypothesis death is caused by a shutdown of the reptilian mind, it's hard to say whether the final symptoms are from the prions or the insomnia.
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    Quote Originally Posted by Numsgil
    Doesn't that support what I said? The thalamus is a part of the brain. It's made up of neurons (last I checked).

    Of course this is a case of brain damage causing insomnia, so it's hard to causally isolate what physical effects are from the damaged thalamus and what's from the sleep deprivation. But the mechanism of insomnia -> brain damage -> body damage seems consistent here.
    You stated that:

    In all probability the higher brain functions (rational thought, etc.) shut down first after a person has been deprived of sleep for a few hours. As the sleep deprivation continues, it continues on down to the mammalian and finally reptilian brains

    This is simply not true. The reticular formation and thalamus are the primary regulators of sleep. The limbic system disturbances would be causing the problems. The effects on the cortex would be secondary and would be the result of impaired alertness. The higher functions would not diminish but be temporarily stifled by a problem with either the thalamus, reticular formation or both.
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    Oops, sorry, I rethought what I wanted to say and edited my post above. Took too long to do it apparently...
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    Quote Originally Posted by Vexer
    do think that "we don't know why we sleep". All the logical and folk-plausible explanations are just that. The evolutionary "night time 'off-mode' explanation (which I Favour) too. But we really don't know why we sleep.
    If some of us do not know why we sleep, it is because we haven't examined how sleep may have evolved among sleeping species. Nearly every species enters a state of rest that could be interpreted as sleep. This suggests a common evolutionary advantage to the sleep process among sleeping species; i.e., we would not have sleeping species if sleep did not offer some survival advantage to ancestral species.

    When we examine the neurological components of sleep in most animals, we find that its various attributes arose at varying stages in neural evolution. Contemporary sleep processes in the human brain appear to be mediated by neurons in the literal hypothalamus. Further down the brainstem, other components of the sleep process appear to suggest an earlier evolutionary incarnation of sleep.

    During the earliy stages of sleep, the brain engages in diminishing activity until the onset of atonia, which is the lost of muscle elasticity. Interestingly, atonia can and does occur in animals without hypothalmic neural structure. This positions atonia as one of sleep's earliest incarnation because it appears to be mediated by neural structures earlier in the brain's evolution than that suggested by the hypothalamus.

    If the brain evolved from some earlier form, we should be able to find some footprint of that form, which we can trace back to some earlier point. Most researchers agree that the brainstem is a primitive component of our central nervous system. Of the brainstems components, the spinal brain (myelencephalon) appears to be the most primitive segment because it most closely resemble the notochord development we find in existant species of primitive animal life.

    When we examine the afferent neural systems of the spinal brain, we find those associated with feeding. This infers that ancestral animals at this stage in brain development engaged behaviors requiring the intake of nutrients. Although the efferents neural paths of the spinal brain suggests movement at this stage in earlier ancestral animals, movement most likely evolved with the evolution of the metencephalon where we find more sophistocated afferent neural systems associated with sound detection. The ability to detect sound suggests ancestral animals at the stage where they were orienting themselves either away from or towards sensory stimuli.

    Early spinal brained animals were probably not as mobile as later metencephlic animals. This suggested lack of mobility infers that these animals had to adopt a stratergy that allowed for survival in the absences of readily available nutrients. It has been suggested that the earliest forms of complex life where a combination of plant and animal. During the prolonged absence of sunlight or nutrients in their primodial sea, immobile animals that could suspend their need for sustainance likely had a survival advantage over those that could not. During the atonic stage of sleep, we find a suspension of muscle readiness with energy devotion to organs more critical to our survival. Atonia appears to be mediated by the metencephalon/myelencephalon brainstem segments. This suggests that the earliest components of sleep evolved as a means to sustain survival through periods of prolonged food privation.

    Although food privation is not a severe concern for some of us, our modern brain rest upon a primitive foundation that was dependent on the periodic suspension of activity to conserve energy for more vital physiological systems. In our brain develpment, evolution built upon its successful systems rather than replace those systems. Sleep evolved from a vestigial need that has become integral to how our contemporary brain functions. I welcome your thoughts.
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    Quote Originally Posted by gottspieler
    The reticular formation and thalamus are the primary regulators of sleep.
    Actually, sleep appears to be mediated by melanin producing neurons in the lateral hypothalamus. The reticular activation systems is believed to be responsible for activation of conscious brain function. The recent discovery of orexin-A producing neurons in the hypothalamus has given researchers hope of bypassing sleep without any aberrant physiological or psychological effects.
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    Quote Originally Posted by DrmDoc
    Although food privation is not a severe concern for some of us, our modern brain rest upon a primitive foundation that was dependent on the periodic suspension of activity to conserve energy for more vital physiological systems. In our brain develpment, evolution built upon its successful systems rather than replace those systems. Sleep evolved from a vestigial need that has become integral to how our contemporary brain functions. I welcome your thoughts.
    That sounds about right. Early sleep development might have been from metabolic needs, but when our more advanced brain developed, it piggy-backed the process for something our advanced brain needs to function.

    My guess is that sleep is a "de-noising" process, where short term memories, non-reinforced thought patterns, etc. are degraded so the trivial ones are removed and the stronger ones are reinforced. I always tend to approach a problem easier after a good night sleep. This might be because other trivial thoughts have been degraded and so I'm less distracted.

    Have there been any sleep deprivation studies on "primitive" animals?
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    Quote Originally Posted by Numsgil
    My guess is that sleep is a "de-noising" process, where short term memories, non-reinforced thought patterns, etc. are degraded so the trivial ones are removed and the stronger ones are reinforced. I always tend to approach a problem easier after a good night sleep. This might be because other trivial thoughts have been degraded and so I'm less distracted.
    I like it. :-D

    My own guess almost contradicts yours: I speculate that sleep smooths the starkness etched in by waking thought. This prevents loops and "cures" us of fixations. The thoughts (now called dreams) running in those somewhat equalized conditions easily stray off course. This exercises neglected synapses and tries arrangements that *sensibly* we'd never reach. The overall effect is like gently blurring a picture.
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    Quote Originally Posted by Pong
    The overall effect is like gently blurring a picture.
    Yeah, that's a good analogy.
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    Quote Originally Posted by DrmDoc
    Quote Originally Posted by gottspieler
    The reticular formation and thalamus are the primary regulators of sleep.
    Actually, sleep appears to be mediated by melanin producing neurons in the lateral hypothalamus. The reticular activation systems it believed to be responsible from activation of conscious brain function. The recent discovery of orexin-A producing neurons in the hypothalamus has given researchers hope of bypassing sleep without any aberrant physiological or psychological effects.
    Thank you. I hadn't heard of this before. Have a link?
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    Quote Originally Posted by gottspieler
    Quote Originally Posted by DrmDoc
    Actually, sleep appears to be mediated by melanin producing neurons in the lateral hypothalamus. The reticular activation systems it believed to be responsible from activation of conscious brain function. The recent discovery of orexin-A producing neurons in the hypothalamus has given researchers hope of bypassing sleep without any aberrant physiological or psychological effects.

    Thank you. I hadn't heard of this before. Have a link?
    Here's a link: http://www.sciencedaily.com/releases...0128160839.htm

    Quote Originally Posted by Numsgil
    My guess is that sleep is a "de-noising" process, where short term memories, non-reinforced thought patterns, etc. are degraded so the trivial ones are removed and the stronger ones are reinforced. I always tend to approach a problem easier after a good night sleep. This might be because other trivial thoughts have been degraded and so I'm less distracted.
    Quote Originally Posted by Pong
    ]My own guess almost contradicts yours: I speculate that sleep smooths the starkness etched in by waking thought. This prevents loops and "cures" us of fixations. The thoughts (now called dreams) running in those somewhat equalized conditions easily stray off course. This exercises neglected synapses and tries arrangements that *sensibly* we'd never reach. The overall effect is like gently blurring a picture.
    The reasons why we sleep and the reasons why we dream are distinct, by way of brain evolution. Sleep appears to have evolved as a means to mediate the metabolism of resting animals, which dreaming appears to reverse at onset. Functional studies of the brain (EEG and fMRI) suggest dreaming to be a type of wakefulness or consciousness amid the sleep process.

    Functional studies suggest that the brain in dream sleep arouses to wakeful levels of activity. Many researchers associate this arousal with memory consolidation or some neuronal repair or upkeep. The evidence in evolution suggests that this arousal is an effect of the uptake of energy by the vestigial aspects of the brain.

    When ancestral animals experienced prolonged periods of food privation, they entered a metabolic state that allowed them to conserve their energy reserves by diverting energy away from systems less vital and towards systems more vital to survival. The emerging brain of ancestral animals was probably one of those vital systems that drew upon the energy reserves of these animals amid a restful state.

    When the contemporary brain enters REM or dream sleep, the body experiences a state of muscle inelasticity called atonia. This state is concurrent with an increase in energy usage by the brain, heart, lungs, and other vital systems. Before ancestral animals evolved those parts of the brain associated with cognition, they evolved those parts associated with their metabolic and autonomic function. It is likely that atonic sleep processes evolved to sustain these primitive brain systems amid periods of privation. As the contemporary brain experiences vestigial uptake of energy by its primitive systems, the neural impact or reverberation of that energy uptake initiates arousal in several brain regions associated with its cognitive processes. Keep in mind these processes probably evolved after those associated with the brain's instinctual systems.

    When the cognitive regions of the brain arouse amid sleep, they do what they were evolved to do--to perceive, assess, and respond to neural stimuli via its primitive subsystems. Some researchers believe that the brain is engaging in some cognitive exercise because of the activations they observe in the brain during dream sleep. In essence, there is nothing unique in this activation that would suggests that the dreaming brain is doing anything more than perceiving, assess, and responding to intracranial neural stimulation or influence.

    Rather than memory consolidation or some other neural purpose, the brain amid dream sleep is merely interpreting its neural experiences as an effect of the vestigial uptake of energy by its primitive subsystems. The experiences we recall as dreams are actually interpretations of unconscious neural influences and impulses rather than some memory or neural exercise process.
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    But that's REM sleep, which is far from the majority of what sleep is. I can accept that maybe REM sleep and dreaming are just something the brain does to keep itself occupied, but that doesn't explain the other 75% of the sleep cycle.
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    Quote Originally Posted by Numsgil
    But that's REM sleep, which is far from the majority of what sleep is. I can accept that maybe REM sleep and dreaming are just something the brain does to keep itself occupied, but that doesn't explain the other 75% of the sleep cycle.
    If by 75% you are referring to the various stages of non-REM, these stages mirror the primitive stages of restful behavior when ancestral animals entered a state of rest that was inclusive of muscle readiness. During contemporary non-REM sleep, arousal from this stage is easier to maintain than arousal from REM (dream) sleep. With the exception of stage 4 non-REM--the final transitional stage before dream sleep--arousal from non-REM is more rapid than arousal from dream sleep. This ability to arouse quickly from non-REM can be associated with the stage of muscle readiness ancestral animals may have required to quickly engage survival behaviors amid periods of rest; i.e., when threaten or when nutrient sources returned, early animals could rapidly arouse from a restful state to address their survival needs. With the exception of dream sleep, our body maintains a state of muscle readiness through all four stages of non-REM sleep.
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    When I'm sleep (dream) deprived, reading late at night, I sometimes catch myself reading the same sentence over and over. I speculate that this is not because I'm sleepy, but because I've been awake too long. I think the normal mechanism of thought tends to build feedback. This is just an inevitable consequence of forming ever "better" routines in a network. Unchecked feedback is fatal. In nature, organisms rely on external disruption to avoid this fate.

    When people get badly locked into "loops" induced seizure (shock therapy) is effective. The aftermath of seizure leaves physical arrangement of neurons unaltered, but the electrical activity that ran through that is flattened. Thoughts then begin afresh. Same person, different trains of thought.

    I've noticed that people regaining consciousness after seizure act like they've awoken from a long sleep, but more so. They won't/can't fixate on things.
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    Quote Originally Posted by Pong
    When people get badly locked into "loops" induced seizure (shock therapy) is effective. The aftermath of seizure leaves physical arrangement of neurons unaltered, but the electrical activity that ran through that is flattened. Thoughts then begin afresh. Same person, different trains of thought.
    The neuropeptide orexin-A has been shown to rapidly reverse the neurological effects of sleep deprivation and the mental fatigue deprivation can cause. Orexin is produced in the lateral hypothalamus and has been shown to be deficient during narcoleptic seizures. If some aspect of sleep evolved as a means to correct faulty brain activity, then orexin-A studies might have shown different results. It seems likely that the mental fatigue or seizures sleep deprivation can cause result from the exhaustion of the peptide orexin, which atonic sleep seems to restore. As I mention earlier, atonic sleep results in the cessation of energy to muscle readiness and the increase of energy uptake by vital bodily systems inclusive of brain structure. This process probably evolved as a means to sustain survival of ancestral animals through period of food privation rather than evolving as a corrective measure of brain function. We are a sleeping species and we experience functional breakdown when deprived of sleep because of our neurological dependency on a vestigial process associated with the survival strategies of our ancient animal ancestors.
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    Quote Originally Posted by DrmDoc
    probably evolved as a means to sustain survival of ancestral animals through period of food privation
    Here's a real disagreement. :|

    The key statement of my post was "Unchecked feedback is fatal." That "law" is easily underestimated. Please appreciate it! A paradox of life is that life tends to seek or create its own feedback. Minds aren't immune. Something must disrupt this, from without or within.

    Notice that smokers are addicted to "the pause that refreshes". They "take smoke breaks" more frequently as the day progresses, and grow manic when denied that reset. Withdrawal symptoms are very similar to sleep deprivation.

    DrmDoc you seem to be saying that sleep isn't really necessary, we're just built to sleep for archaic reasons. And I'm saying sleep is one very good way to reset feedbacks all thinking animals are susceptible to. So we're each locked in our respective pigheaded views. I suggest we each sleep on that problem :wink:
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    DrmDoc, I'm not denying anything you're posting, but you seem to be saying that sleep has no effect on the mind what so ever. If this were true, why is it that the first symptom of being sleepy is reduced cognitive ability? If sleep were only a means of reducing metabolism to conserve energy, one would expect it to be similar to hunger. Meaning if we had to we should be able to go weeks without sleep same way we can go weeks without eating. And one would also expect starving people to sleep longer to conserve energy. Maybe up to 15 or even 20 hours a day.

    One interesting experiment would be to study the hibernation and how it compares to regular sleep. Hibernation is clearly a method to conserve energy.
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    Quote Originally Posted by Pong
    The key statement of my post was "Unchecked feedback is fatal." That "law" is easily underestimated. Please appreciate it! A paradox of life is that life tends to seek or create its own feedback. Minds aren't immune. Something must disrupt this, from without or within.

    Notice that smokers are addicted to "the pause that refreshes". They "take smoke breaks" more frequently as the day progresses, and grow manic when denied that reset. Withdrawal symptoms are very similar to sleep deprivation.
    If I understand correctly, you are equating “Unchecked feedback” with addiction. Addiction occurs when the normal functions or processes of the brain are unbalanced by an artificial or foreign influence. Using your example, smoking introduces a foreign substance (nicotine) into brain structure that supplants the normal processes of the brain, which leads to dependency. Unlike addiction, neuropeptide production of orexin is how the brain evolved to facilitate its conscious neural processes; i.e., it is the oil that appears to lubricate the wheels of consciousness.

    If by “feedback” you are referring to a type of overheating in the neural circuitry of the brain, then orexin would not have been as clearly effective in restoring proper brain function in the absences of sleep; i.e., if the brain demanded periodic shutdowns to cool or soothe its circuitry, then substances that cause arousal of that overused circuitry would not restore proper function to the brain as orexin seems to do.

    Quote Originally Posted by Pong
    …you seem to be saying that sleep isn't really necessary, we're just built to sleep for archaic reasons.
    Well, no and yes; sleep is necessary because that is how our contemporary brain evolved to function. To deny the “archaic reasons” for sleep is to deny the evolutionary process; i.e., the iterative nature of life is not a sufficient explanation for how the attributes of life originated. If feedback is an attribute of contemporary brain structure, has it always been? If so, what was the nature of its origin?

    Quote Originally Posted by Pong
    …I'm saying sleep is one very good way to reset feedbacks all thinking animals are susceptible to. So we're each locked in our respective pigheaded views.
    Rather than “pigheaded,” I like to think of myself as fairly liberal minded. Perhaps I misunderstood your concept of “feedback.” I understand how difficult it may be for some to accept certain concepts without fully evaluating the evidence in science behind those concepts. Although I have tried to convey that evidence in brief terms, clearly some require much more than I have provided.

    Quote Originally Posted by Numsgil
    …you seem to be saying that sleep has no effect on the mind what so ever. If this were true, why is it that the first symptom of being sleepy is reduced cognitive ability?
    The absences of orexin production during the sleep process and its effect in restoring cognition after sleep deprivation suggests that sleep may be essential to the natural production of a peptide that is vital to the cognitive (wakeful) circuitry of the brain. If the artificial introduction of this peptide into brain structure restores cognition, what need have we for sleep?

    Contemporary sleep was built upon a vestigial process that is essential to the normal function of the brain’s primitive elements. If the more recent elements of brain structure had evolved in an environment that was independent of its primitive elements, then sleep would not be necessary. Understand, the primitive elements of brain structure evolved sleep as a survival strategy of ancestral animals and the brain’s contemporary elements rise from the foundation of its primitive elements and survival strategies. Rather than replace past strategies because survival conditions have changed, evolution appears to have build upon the successful design of those strategies.

    Quote Originally Posted by Numsgil
    If sleep were only a means of reducing metabolism to conserve energy, one would expect it to be similar to hunger. Meaning if we had to we should be able to go weeks without sleep same way we can go weeks without eating.
    I think I understand our differences here: You infer the nature of sleep from what it is now, I infer that nature from how it likely evolved. What sleep is now is not what it was at its inception. Also, you infer that the nature of hunger and sleep are the same. We can keep hunger at bay by drawing on the energy reserves of the body; however, contemporary sleep appears to engage as some neural reserve (orexin, perhaps) nears depletion. Because the contemporary brain appears to require downtime to manufacture orexin, we cannot sustain consciousness after the depletion of this peptide.

    Quote Originally Posted by Numsgil
    And one would also expect starving people to sleep longer to conserve energy. Maybe up to 15 or even 20 hours a day.
    Indeed, the metabolism of people who haven’t eaten over long periods does slow down nearly as much as it would during sleep; however, hunger and the contemporary nature of sleep is not the same. When we remove those parts of the brain associated with contemporary sleep, we find that test animals experience atonic muscle collapse until fed or otherwise stimulated. This suggests that primitive animals may have entered prolonged states of inactivity during periods of prolonged privation.

    Quote Originally Posted by Numsgil
    One interesting experiment would be to study the hibernation and how it compares to regular sleep. Hibernation is clearly a method to conserve energy.
    Interestingly, hibernating animals must periodically experience normal stages of sleep to sustain hibernation. The distinction between hibernation and sleep is that the former likely evolved after the inception of sleep during an era of severe hardship. Hibernation appears to have evolved upon the foundation of sleep in animals that experienced more extreme survival conditions than those experienced by animals ancestral to humans.
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    Quote Originally Posted by Pong
    If the artificial introduction of this peptide into brain structure restores cognition, what need have we for sleep?
    That would be really cool if it's true. Has it been confirmed experimentally, or is this still theoretical? My present thinking is that whatever refactory process the brain undergoes during sleep is a structural one instead of a chemical one. That is, the connections are being dulled to weed out noise signals. But I'm open to the idea that it's just a chemical peptide deficiency that the brain needs time to correct every day.

    Of course, I would question why this peptide recovery takes 1/3 of our time. Why couldn't it evolve to be faster?

    Contemporary sleep was built upon a vestigial process that is essential to the normal function of the brain’s primitive elements. If the more recent elements of brain structure had evolved in an environment that was independent of its primitive elements, then sleep would not be necessary. Understand, the primitive elements of brain structure evolved sleep as a survival strategy of ancestral animals and the brain’s contemporary elements rise from the foundation of its primitive elements and survival strategies. Rather than replace past strategies because survival conditions have changed, evolution appears to have build upon the successful design of those strategies.
    I fully understand and agree with this. Evolution is an incremental process, and it tends to recycle old functionality for new purposes. But there was (and is) a very real fitness cost to sleep. We would not have evolved to be so crippled by sleep deprivation unless the benefits (cognitive ability) far outweighed this cost. As you say, what sleep is, and what it was are very different.

    We can keep hunger at bay by drawing on the energy reserves of the body; however, contemporary sleep appears to engage as some neural reserve (orexin, perhaps) nears depletion. Because the contemporary brain appears to require downtime to manufacture orexin, we cannot sustain consciousness after the depletion of this peptide.
    As above, this is very interesting. What might prevent the manufacture of this orexin during consciousness? Why can't more be reserved (allowing us to stay concious for much longer)? And why can't more be produced faster (so maybe we only would need 4 hours of sleep a night)?

    Interestingly, hibernating animals must periodically experience normal stages of sleep to sustain hibernation.
    Hmm, this is interesting...
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    I don't know about you guys but I sleep because I'm tired... *bah bom tshh*
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    Quote Originally Posted by Numsgil
    That would be really cool if it's true. Has it been confirmed experimentally, or is this still theoretical? My present thinking is that whatever refactory process the brain undergoes during sleep is a structural one instead of a chemical one.
    Absent at the onset of narcolepsy, orexin-A has been shown to eliminate sleepiness when reintroduced into brain chemistry via nasal aerosol. Here is info on a paper from my notes on this subject:

    Sam A. Deadwyler, Linda Porrino, Jerome M. Siegel, and Robert E. Hampson: Systemic and Nasal Delivery of Orexin-A (Hypocretin-1) Reduces the Effects of Sleep Deprivation on Cognitive Performance in Nonhuman Primates. The Journal of Neuroscience, December 26, 2007, 27(52):14239-14247; doi:10.1523/JNEUROSCI.3878-07.2007

    Quote Originally Posted by Numsgil
    Evolution is an incremental process, and it tends to recycle old functionality for new purposes. But there was (and is) a very real fitness cost to sleep. We would not have evolved to be so crippled by sleep deprivation unless the benefits (cognitive ability) far outweighed this cost. As you say, what sleep is, and what it was are very different.
    If the primitive structures that generate the floor of sleep in our brain were the peak measure of their evolution for this process, then the benefits of sleep in its archaic form to ancestral animals was probably not as crippling to their cognitive abilities; i.e., without the cognitive features of contemporary brain structure, sleep was very different for ancestral animals. In the surgical absence of recent structures in test animals, sleep is as it probably was.

    Quote Originally Posted by Numsgil
    As above, this is very interesting. What might prevent the manufacture of this orexin during consciousness? Why can't more be reserved (allowing us to stay concious for much longer)? And why can't more be produced faster (so maybe we only would need 4 hours of sleep a night)?
    The research is very preliminary but promising all the same. Some researchers are asking questions similar to yours. For example, decerebration studies with brain developments intact through the thalamus show continued activation. This could suggests some countermeasure to continued consciousness evolved with the evolution of the cortex. This is important when we consider the low position of the hypothalamus relative to the thalamus and cortex.
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    Very cool. But does the research indicate that Orexin-A reduces sleep debt, or is it just a stimulant like caffeine or amphetamines where you just postpone the inevitable?
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    Indeed, the study showed no adverse effects of deprivation persisting into normal sleep after Orexin-A treatments. Test animals appeared to exhibit normal sleep habits.
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    I'd like to concede that we could plausibly remain awake indefinitely, and with carefully regulated environment and drugs not behave like meth tweekers on their 3rd day.

    The pursuit of eternal wakefulness has much in common with the pursuit of eternal youth. In both cases larger consequences are ignored. Shamelessly, I admit that if it weren't for regular disruption my mind would carve its own death valley, and if it weren't for my body's timely demise my genes would wallow in a grave of obsolescence.

    So if my sleep was "cured", I'd need a routine dragging-back to square one, to keep me grounded. This disruption would have to be unavoidable by me, my worst enemy. Maybe knock me unconscious every day or so?
    A pong by any other name is still a pong. -williampinn
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    If I could, I'd like to stay awake for maybe 100-150 hours at a time, then go a few days under a normal sleep routine. I always find that I'm actually accomplishing whatever I wanted to accomplish at about 2 hours before I should be in bed.
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    I would personally think that sleep is required in order for our brains to replenish given areas of the brain - neurons, of which are responsible for the production of consciousness during our waking reality; our conscious minds are shut off in order for these areas (Portions, and neurons) of the brain to be replenished. However, contrary to consciousness being shut off - otherwise this would be the equivilence of temporary death - the brain quickly switches consciousness to another portion of the brain prior to a complete deactivation of consciousness (During our process to internal sensory perception (Dreams), our consciousness is reduced; rational thought, external sensory perception, will and thought is reduced), resulting in the 'dreaming brain'; our unconscious consciousness switch. Given portions of the brain of which were unconscious, become conscious during the sleep whilst the contrary - conscious portions, become unconscious for neural replenishing.

    In order to pertain awareness, and to prevent "temporary death", our brains quickly reinitiate the conscious mind to another portion of the brain, consisted with a lack of integrity; the removal of rational/realization portions fundamental to the recognization of physical reality. During our unconscious experience, or conscious unconscious; dreaming - experiences, our conscious portions of the brain - and mind, replenish energy and other essentials for functionality. In addition to pertaining the health of neural functionality, our brains pertain consciousness through "dreaming".
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    Quote Originally Posted by Pong
    The pursuit of eternal wakefulness has much in common with the pursuit of eternal youth. In both cases larger consequences are ignored. Shamelessly, I admit that if it weren't for regular disruption my mind would carve its own death valley, and if it weren't for my body's timely demise my genes would wallow in a grave of obsolescence.
    Theoretically, if I may, you might experience psychosis if a neuropeptide replacement therapy was ineffective in restoring balance to your brain chemistry. However, the real danger in such therapy involves the relative metabolic increase that would likely result from interruption of the sleep process. On average, we spend nearly a third of our life sleeping. The average adult requires from 7 to 8 hours of sleep, per 24 hour period, to maintain optimum performance levels. Maintaining the performance demands of the body for a full 24 hours a day would probably increase the metabolic demands of the body by almost a third. To sustain a 24 hour wakeful program, we would probably have to increase our dietary intake by at least one third more than is our usual. Multiply this by thousands of individuals with increased dietary pressures and imagine the added strain on society’s resources these pressure could potentially foster. Once again, humanity may not be fully considering the consequences of its proposed advances.

    Quote Originally Posted by blue_space87
    During our unconscious experience, or conscious unconscious; dreaming - experiences, our conscious portions of the brain - and mind, replenish energy and other essentials for functionality. In addition to pertaining the health of neural functionality, our brains pertain consciousness through "dreaming".
    I think that dreaming is a byproduct of a vestigial process instead of a means to sustain conscious functionality as some have suggested. I think this way because all the neural processes that currently propagate sleep and dreaming appear to have evolved before the brain could actually dream. To dream, the primitive brain would have required the ability to form a cognitive environment within its neural structure that was independent from its conscious experience. My investigation suggests that the ability to dream evolved with the emergence of the cortex long after the mechanisms for dreaming evolved in the brainstem. With the emergence of the cortex, the primitive brain had a sophisticated data storage device which it could use to mentally attenuate its survival experiences before engaging survival behaviors; i.e., the cortex gave the primitive brain the ability to imagine experiences and responses.

    Here’s the curious thing, the peptide (orexin-A) some consider essential for proper conscious activation of brain function is not present during the unconscious activation of REM (dream) sleep. For those who do not fully understand the nature of dream sleep, the non-presence of orexin appears to be an appropriate explanation for the seemingly erratic behavior of the dreaming brain. However, the brain during dream sleep is engaging in a cognitive function rather than erratic behavior; i.e., dreaming is a cognitive function of the brain amid the sleep process.

    The imagery we recall as dreams upon arousal from sleep are evidence of the cognitive processes of the brain when its neural connection to physical/material reality partially deactivates. The imagery in our dreams are every bit as logical and rational as our experiences in conscious reality. The difference is that our dream experiences conform to the logic and reason of mental experience rather than that of physical/material experience. This distinction is important because it suggests that orexin may be essential for reasons other than proper cognitive function since it is not present during the cognitive function that dreaming suggests.

    From my study of brain function amid the sleep process, the dreaming brain’s disconnect from physical/material experience suggests to me that orexin may be essential to how the conscious brain receives and transmit physical/material sensory information. Perhaps the presence of orexin sustains arousal by facilitating the flow of sensory experience. Therefore, what may be essential to proper conscious brain function might be that which facilitates the proper reception and transmission of sensory experience.
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    A very interesting fact is that many hormones have a rhythmic cycle and influence the sleep/awake rhythm.
    Some of the Hormones are for example:
    -Growth Hormone (GH)
    -Cortisol
    -Melatonin
    ....

    For example Cortisol is said to have something to do with getting up in the morning as it has its highest peaks shortly before we wake up. During the day the cortisol levels fall until they reach their low in the evening / early night where we start getting tired again....

    It was investigated that Melatonin has a special function as it is produced by the pineal gland which is said to work as "biological clock" of the body. Indeed in the latest publication (see the literature) says: "The rhythm of melatonin, peaking at 2-3 am, acts as an endogenous synchronizer that translates the environmental photoperiodic signal in chemical information for the cells. The sleep/wake cycle is a typical biological rhythm synchronized by melatonin, and the sleep/wake cycle alterations of chronobiological origin, are very sensitive to melatonin treatment."

    Another fact is that during the sleep, new synapses are built and that there are different stages of sleeping with different characteristics of brain activity which can be measured in an EEG.
    All in all I think that sleep is a far more complex thing than we imagine...


    Literature:
    1: Rev Neurol. 2009 Mar 1-15;48(5):245-54, "Melatonin, synthetic analogs, and the sleep/wake rhythm" Escames G, Acuña-Castroviejo D.
    2: Chronobiol Int. 2001 Mar;18(2):249-61, "Circadian rhythmicity of cortisol and body temperature: morningness-eveningness effects."Bailey SL, Heitkemper MM.
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    Quote Originally Posted by pat1512
    A very interesting fact is that many hormones have a rhythmic cycle and influence the sleep/awake rhythm.
    Some of the Hormones are for example:
    -Growth Hormone (GH)
    -Cortisol
    -Melatonin

    ...All in all I think that sleep is a far more complex thing than we imagine...
    I agree; however, considering where these hormonal influences arise in the brain, it would seem that sleep predominately serves a ancient biological process rather than a cognitive function. In these hormonal influences of the brainstem, I think we can clearly perceive the ancient metobolic roots and function of sleep before the sleeping brain evolved those cortical structures associated with cognition.
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    But then, why do insomniacs not suffer from stunted mental and physical development?
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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    Quote Originally Posted by drowsy turtle
    But then, why do insomniacs not suffer from stunted mental and physical development?
    Insomnia is primarily a condition of a mature brain that has reached its peek of mental or physical development. We do know that sleep disturbances in children could be evidence of severe psychosis. Nevertheless, insufficient sleep has been shown to have significant mental and physical consequences for both children and adults; i.e., insomnia may cause or be a symptom of some adverse mental or physical condition.
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    DrmDoc,

    So we sleep because we were once unsessile sea sponges (things)?
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    The body needs time to repair itself ,because many cells died during the day.So we sleep without doing anything except dreaming,our body products new cells during this time. That is also the time for our brain to rest and clear useless information.
    PS:Personal view
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    Quote Originally Posted by Vexer
    So we sleep because we were once unsessile sea sponges (things)?
    Well, yes and no; we sleep because of what we inherited from ancestral animals less cognizant and thoughtful than we are presently.

    Quote Originally Posted by genious129
    The body needs time to repair itself ,because many cells died during the day.So we sleep without doing anything except dreaming,our body products new cells during this time. That is also the time for our brain to rest and clear useless information.
    Although one's own perspective may be personally satisfying, it may not always be informed. If one's goal is self-enrichment and enlightenment, should one be satisfied with just a personal belief without the merest interest in investigating whether that belief is truly valid? I may espouse many ideas about the true nature of sleep but I am never so satisfied as to believe what I think is all there is. I welcome your thoughts.
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    I have read a news.A new study attempts to address just why we sleep.

    All animals do it.Even the dolphin, which is often used as an example of an animal that does not sleep because it keeps moving, has developed its own method of sleeping. The dolphin shuts down one half of its brain, swimming with one eye closed, and exhibiting the slow waves characteristic of deep sleep.

    "The very fact that dolphins have developed the remarkable specialization . . ., rather than merely getting rid of sleep altogether, should count as evidence that sleep must serve some essential function and cannot be eliminated," Cirelli says.

    Cirelli also points to sleep deprivation, and the after-effect of having gone a long time without sleep, as examples of the necessity of it. Sleep deprivation has been shown to kill animals like rats, flies and cockroaches, as well as humans who suffer from genetic insomnia. And when a human rebounds from lack of sleep, they sleep for a long time to recuperate.

    Their hypothesis suggests that sleep acts as a way for the brain to regroup after a hard day. Sleep theoretically gives the synapses – which have been escalating in strength during the day – a chance to slow down again, and return to a base level. Given that the brain uses 80% of its energy in order to keep the synaptic activity happening, there is an obvious need for the brain to rest.

    They also suggest that sleep allows for the consolidation of new memories, and the trashing of older, random and unimportant memories from the day passed. This theoretically allows for more learning the following day. "While there may still be no consensus on why animals need to sleep, it would seem that searching for a core function of sleep, particularly at the cellular level, is still a worthwhile exercise," Cirelli concludes.

    Posted by Josh Hill.
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    I've referenced some of Cirelli's work in my most recent book on the dreaming brain. However, work like his is predicated on the contemporary nature of sleep without a foundation in how that nature arose and propagated into sleeping species. How did dolphins, whales, and birds evolve a type of half-brain sleep that is distinct from humanity? The obvious answer is that there must have been some survival impact on ancestral animals leading to a divergence of the sleep process.

    What sleep is at present does not, in my opinion, define how it evolved and why humanity and other sleeping species continue this process. We are what we seem to be and manifest because of the way we have evolved. When we examine how the various constituents of brain structure contribute to the sleep process, we get a sense of how that process may have evolved. This is possible because our brain bares the footprints of it neurological evolution by the very nature of it seemingly primitive to recent (spinal cord to cortex) structure. Although sleep may be an intricate process, it is not a difficult process to understand and define if we truly understand its evolution--in my opinion.
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    Quote Originally Posted by DrmDoc
    I think that dreaming is a byproduct of a vestigial process instead of a means to sustain conscious functionality as some have suggested. I think this way because all the neural processes that currently propagate sleep and dreaming appear to have evolved before the brain could actually dream. To dream, the primitive brain would have required the ability to form a cognitive environment within its neural structure that was independent from its conscious experience. My investigation suggests that the ability to dream evolved with the emergence of the cortex long after the mechanisms for dreaming evolved in the brainstem. With the emergence of the cortex, the primitive brain had a sophisticated data storage device which it could use to mentally attenuate its survival experiences before engaging survival behaviors; i.e., the cortex gave the primitive brain the ability to imagine experiences and responses.

    Here’s the curious thing, the peptide (orexin-A) some consider essential for proper conscious activation of brain function is not present during the unconscious activation of REM (dream) sleep. For those who do not fully understand the nature of dream sleep, the non-presence of orexin appears to be an appropriate explanation for the seemingly erratic behavior of the dreaming brain. However, the brain during dream sleep is engaging in a cognitive function rather than erratic behavior; i.e., dreaming is a cognitive function of the brain amid the sleep process.

    The imagery we recall as dreams upon arousal from sleep are evidence of the cognitive processes of the brain when its neural connection to physical/material reality partially deactivates. The imagery in our dreams are every bit as logical and rational as our experiences in conscious reality. The difference is that our dream experiences conform to the logic and reason of mental experience rather than that of physical/material experience. This distinction is important because it suggests that orexin may be essential for reasons other than proper cognitive function since it is not present during the cognitive function that dreaming suggests.

    From my study of brain function amid the sleep process, the dreaming brain’s disconnect from physical/material experience suggests to me that orexin may be essential to how the conscious brain receives and transmit physical/material sensory information. Perhaps the presence of orexin sustains arousal by facilitating the flow of sensory experience. Therefore, what may be essential to proper conscious brain function might be that which facilitates the proper reception and transmission of sensory experience.
    That's what I said; the conscious mind is partially deactivated; it is transfered from the portion of neurons that are currently producing conscious experience to an alternative aspect of the brain. As a result, consciousness is not completely deactivated, and is rather slowly transfered as opposed to instantly being transfered; if it was shut off and then reactivated, this be essentially be equivilent to death. I don't believe our brains during our unconscious experience pertain our perception for random experience, or shut us off, as I rather believe that our unconscious pertains our perception, or consciousness rather, as much as it can. An example would be a spontanous incident that caused major damage to the body, or exceeded the pain to which the conscious mind could percieve; something that may have been too much for us to experience; we may fall unconscious as a result, but would still experience some form of perception internally. Although, this is probably not confirmed, I do believe that whilst in a coma, or unconscious by external means (e.g. anesthesia), our experience is generated within a deep unconscious environment. One of the reasons is due to personal experience; I was to have surgery at one point and was given anesthetic, and as a result I fell unconscious during the entire procedure. Upon awakening, I had began to remember my internal (unconscious) experiences during the procedure; by memory, this felt as if it happened during the entire procedure (This didn't feel as if it was compressed memory of some sort, and had felt as if I experience conscious existence during the entire time I was placed unconscious).

    I do agree with you on the dreaming brain, that it is of a system that enables for ourselves to prepare for the worst, to solve and to consolidate our percetion, or position in life. However, I also, and still believe it is a way in which our brain transfers experience (Or awareness rather) to another portion of the brain in order to replenish the resources for that given portion that was initially producing awareness. As a result, other processes can begin; body growth, healing and health-associated neural activity can be activated, most of which may be of severe inconvinience to conscious perception.

    Orexin-A may be a way for activating external sensory perception. However, although those with Narocolepsy may experience external perception, they lack proper cognitive function; they are unable to process information in correlation to the external environment. Orexin-A may be essential to enabling for the conscious mind to utilize processes that interact with the external environment; the lack of such may be contrary, and would enable for the conscious mind to reduce its external interaction and thus, would switch to internal means for interactivity.
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    Quote Originally Posted by drowsy turtle
    But then, why do insomniacs not suffer from stunted mental and physical development?
    Oh wow, what an avatar!
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    Quote Originally Posted by blue_space87
    That's what I said; the conscious mind is partially deactivated; it is transfered from the portion of neurons that are currently producing conscious experience to an alternative aspect of the brain. As a result, consciousness is not completely deactivated, and is rather slowly transfered as opposed to instantly being transfered; if it was shut off and then reactivated, this be essentially be equivilent to death.
    That isn’t precisely what I’ve tried to convey; the cognitive awareness that we associate with thought and reasoning is not active between the conscious and unconscious states of awareness that we, respectively, associate with the awake and dreaming state of brain function. The only states we can credibly associate with a form of active cognition are those suggested by the awake and dreaming states of the brain. Since the direction of your comments appear to address those I've made in our discussion of the unconscious mind, I will post my further comments there.
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    Quote Originally Posted by DrmDoc
    Quote Originally Posted by blue_space87
    That's what I said; the conscious mind is partially deactivated; it is transfered from the portion of neurons that are currently producing conscious experience to an alternative aspect of the brain. As a result, consciousness is not completely deactivated, and is rather slowly transfered as opposed to instantly being transfered; if it was shut off and then reactivated, this be essentially be equivilent to death.
    That isn’t precisely what I’ve tried to convey; the cognitive awareness that we associate with thought and reasoning is not active between the conscious and unconscious states of awareness that we, respectively, associate with the awake and dreaming state of brain function. The only states we can credibly associate with a form of active cognition are those suggested by the awake and dreaming states of the brain. Since the direction of your comments appear to address those I've made in our discussion of the unconscious mind, I will post my further comments there.
    Ah, sorry. Well, between the waking reality and dreaming; the transition from the waking reality to sleep; the deactivation, or transition of conscious experience effectively reduces our perception to a mere thought, or something of other that is of low cognitive acitivity in comparison to the level of activity of the present or during a dreaming state. What I'm saying is, during sleep we are still aware, but only at a minimum as opposed to engaging in a cognitive environment or throughout the external environment.
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    blue_space87

    What?
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  62. #61 sleep 
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    Everyone experiences occasional sleep problems, but getting a good night’s sleep is essential for feeling refreshed and alert during the day. Lack of sleep might make you feel foggy and unable to concentrate, or just a lesser version of your normal self. Sleep problems will eventually disrupt your work, family and personal relationships.
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    :P :P actually no one knows exactly the reason of our sleep ...... obviously we are hummans and need rest after a long work ... its not our body that works or that need rest .... also we have a most important part of our body that is brain it also need rest ......:P :P :P and someone who dont like to sleep got a suggestion to become a vampire .... because vampires dont sleep at all ......
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    Quote Originally Posted by mikehussy1990
    actually no one knows exactly the reason of our sleep ......
    Actually, some of us do know why we sleep. Those who don't have yet to piece together the neurological and evolutionary evidence illuminating sleep's primal emergence.
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    We sleep in order to learn, secret hormones for growth and repair and 101 other reasons

    Everything happens for a reason
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  66. #65 Why do we sleep? 
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    Sleep is very important... We need to make a sleep to gain our fatigue... Become healthy and have a full of energy... ^^
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    Sleep is most important in every person's life. According to doctor we must take 7 to 8 hours sleep per day. Due to this we feel healthy and relax. Sleep is effect on our health and mood. We take sleep for rest.
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  68. #67  
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    for the subconscious to process our thought, solve problems and replenish depleted conscious energy
    Imagination is key to the logic of thought, a greatest eternal truth.

    ME
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    Why we sleep is a product of evolution. Rather than rely on unstudied opinion and nonsense, if you are sincerely interested in understanding sleep, you should evaluate the empirical evidence in brain function and what that evidence suggests about the origin of the various components of sleep. The earliest incarnation of sleep likely evolved as a means to conserve energy between periods of feeding by ancestral animals. As those animal gained new brain structures and became more active, what was once a means to conserve energy became a means to sustain and restore vital physiological and neurological systems through periods of rest and inactivity. We sleep today because that is how our brain evolved to sustain function through prolonged periods of physical inactivity.
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    DrmDoc, My question to you is this, is sleep induced by darkness, or the absents of light? Why is melanin produced in the darkness, and what does it have to do with sleep?
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    Sleep is very important for the nourishment of healthy life. It is very necessary for the body to take rest having spending a long busy day, proper sleep keeps your mind, digestive system and lungs working properly as these organs even work when you go to sleep. Sleeping well is also good for healthy eyes and it prevents dark circles as it occurs due to lack of sleep.
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    I find it interesting that evolution has brought us to the point of requiring (for the sake of argument) 8 hours of "down time" for every 16 hours of "up time". I think I can speak for most of us when I say that I'm *out* when I'm sleeping, and that I'd be among the statistics just as much as those campers we hear about who get chewed up by bears in the middle of the night. To think that it's advantageous to be vulnerable to predators one-third of every day for the sake of ... (whatever sleep gives us)! That's quite an advantage that it would outweigh such danger of death. I don't think that we take such great risks for anything else.

    What I can't figure is why snoring was never bred out of us. It's like having a neon light flashing FREE FOOD. And the way some guys snore, they wouldn't last a week in the wilds!
    Grief is the price we pay for love. (CM Parkes) Our postillion has been struck by lightning. (Unknown) War is always the choice of the chosen who will not have to fight. (Bono) The years tell much what the days never knew. (RW Emerson) Reality is not always probable, or likely. (JL Borges)
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    As we know sleep is very important for a healthy life because a body system needs rest after passing the whole day.
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    We sleep because we are sleepy. Why do we eat, because we are hungry... This answer has probably been given by other trolls though..

    What I can't figure is why snoring was never bred out of us. It's like having a neon light flashing FREE FOOD. And the way some guys snore, they wouldn't last a week in the wilds!
    I can think of a reason.. Ever heard a guy snore.. Ever thought about how it would sound like amplified in a cave? Yes, it would sound like a lions rawr.. And for what reason do animals not think about free food when they hear a lions rawr? Well, because they would be the food.. (just opting)
    Growing up, i marveled at star-trek's science, and ignored the perfect society. Now, i try to ignore their science, and marvel at the society.

    Imagine, being able to create matter out of thin air, and not coming up with using drones for boarding hostile ships. Or using drones to defend your own ship. Heck, using drones to block energy attacks, counterattack or for surveillance. Unless, of course, they are nano-machines in your blood, which is a billion times more complex..
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  75. #74  
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    Snoring? Is mostly a sign of ENT problems and/or overweight.

    If you're thinking of primitive life, being overweight was not a problem. ENT infections would have been temporary - or fatal.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
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    Quote Originally Posted by could147 View Post
    No one knows why we sleep, but it’s certain that we need to. People who are prevented from sleeping begin to suffer obvious effects after a few days—they think less clearly, and they fall asleep during the working hours.
      There are no rules about sleep. Generally speaking, grown-ups sleep about 7 and a half hours each night and probably more than 60 percent get between seven and eight hours. But perhaps eight percent are quite happy with 5 hours or less, and four percent or so find that they want ten hours or more. If you feel all right, you’re probably getting enough sleep. The important thing is not to worry how much other people get—their needs may be different. Exercise doesn’t seem to increase the need for sleep—office workers, for example, sleep for about as long as people doing physically active work.
      Children sleep more than grown-ups—perhaps 14 to 18 hours soon after birth, going down to grown-up levels by early teenage . Sleep patterns also tend to be different in the old people, who may sleep less at night than they did when younger, find sleep getting more broken, and often make it a rule to sleep during the daytime.
    I am not sure that nobody know why we sleep, I think some of us have part answers and the rest rely on science. if science cannot help us then we begin to guess and the whole question falls apart. This is my take. If we look at the different types of energy that drives the human being we should be able to see that there are several different types. The body needs physical energy, it is produced from food.Our brain needs mental energy it is produced from thought. We need emotional energy, it is produced by feelings and so on. All these different energies types are produced in the realm of matter. The problem for most humans is they do not relate spirit to energy, and most of all we fall very short when it comes to dark matter or dark energy. Sleep takes us to a dark place where we shut off all the perceptive organs and rely on instinctive resuscitation. There is an organ in the brain that relates to sleep called the Pineal organ. This organ is responcible for our sleep state because it cannot function in light. Modern science only study this organ in a small way and so there is not a lot of info to draw on. However there are some people who knows a lot about this phenomenon but cannot express this because it entails going into the spirit world and science stops regrettable at that point. To make what I am saying shorter, we have to sleep to retank dark energy, this can only happen at night in the dark. You can eat all you want if you do not sleep you cannot function. In the end it has a lot to do with how we store carbon.
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  77. #76  
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    I sleep that i may dream
    I dream that i may store my short term memories in long term files
    I store my memories that i may order my experiential thoughts
    I order my experiential thoughts that i may solve problems
    I solve problems that I may be comfortable
    I seek comfort that I may sleep

    Why do you sleep?
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