This question requires some innovative ideas and insight

[JJFrank]

In the past I have not had much success in posing questions on this forum, but I keep hoping that some perceptive and original minds might read this and offer some original insight. I know that scientists have no idea why we sleep. Any original ideas about that would be welcome, but my question is a little different. My question is : Why do we lose consciousness when we sleep? Many people have posited fanciful ideas about pseudo-spiritual and semi-religious dimensions of reality, most of which I have heard before and which I completely reject as patently false, but if those are the only explanations you have, well, go ahead and state them again, but i would really really appreciate if there is anyone with some original insight on this question. JJ

[EbbTide000]

In the past I have not had much success in posing questions on this forum, but I keep hoping that some perceptive and original minds might read this and offer some original insight. I know that scientists have no idea why we sleep. Any original ideas about that would be welcome, but my question is a little different. My question is : Why do we lose consciousness when we sleep? Many people have posited fanciful ideas about pseudo-spiritual and semi-religious dimensions of reality, most of which I have heard before and which I completely reject as patently false, but if those are the only explanations you have, well, go ahead and state them again, but i would really really appreciate if there is anyone with some original insight on this question. JJ Very good question Frank Why do different animals lose consciousness for vastly different amounts, daily, like: Following is a mammal sleep chart giving a variety of animals and their required hours of sleep: Average amount of sleep per day for mammals 2 hrs (giraffe) 3 hrs*(donkey, horse, roe deer) 4 hrs*(elephant, goat, sheep, cow)* 7 hrs*(dolphin) 8 hrs*(humans, rabbit, pig, guinea pig) 9 hrs*(mole, dog) 10 hrs*(chimpanzee, rhesus monkey, squirrel monkey, baboon, hedgehog)* 11 hrs*(beaver, fox, jaguar) 12 hrs*(gorilla) 13 hrs*(chinchilla, wolf, raccoon, rat, mouse)* 14 hrs*(hamster, gorillas)* 15 hrs*(cat, squirrel, chipmunk, gerbil rat) 17 hrs*(owl monkey (the primate that sleeps the most!) (3))* 19 hrs*(opossum) 20 hrs (bat) You can find this chart at the following link: Animals: Duration & Schedule ■■■ Do Dolphins Sleep? - Greg Foot Answers Your Quest…: http://youtu.be/I7yy4H1wiGI ■■■ And Baby dolfins don't sleep. ■■■ Baby Dolphins Don't Sleep ■■■ I wanna know Y 2.

[Synergeon]

In my opinion it could be that consciousness expansion is an evolutionary necessity and so our brains shifts to those different consciousness states (REM phase, SWS states and so on...) by inducing sleep, in order to give us the possibility to become more awake, which lead to less stress, better cognitive skills and so on. So lucid dreaming is the purpose of sleeping. I've heard many spiritually advanced people don't need sleep, and I believe that's because they're somewhat always in a state very similiar to the REM one.

[ThreeCat]

I don't think we ever "lose" consciousness when we sleep. This is the main reason we can become lucid in NREM, REM, and delta stages: we are already conscious, we just need to become aware. By extension, it is arguable that we never "lose" consciousness, except when we die. And maybe not even then EDIT: Thank you, EddTide, for the information on length of sleep in animals. Do you know which animals are biphasic, which are polyphasic)? Also, I am very interested that a jaguar sleeps so little. I was under the impression that most big cats sleep most of the day (thinking of lions, with their 19-20 hrs of rest throughout the day).

[sisyphus]

Viewed through the lens of evolution and physics, a standard answer to just about everything is: to conserve energy. If you are unconscious, you don't move. And if you don't move, you use less energy. Following that thesis, the reason why some animals sleep more or less than others probably has to do with how efficiently they can gain more energy (what they eat). Another factor would be the danger of staying still for a long period of time. An apex predator like a lion can acquire a large and nutritious meal without much time investment (a zebra will do) and there aren't many threats to a sleeping lion. On the other hand, an herbivore like a cow has to spend a lot of time acquiring enough energy and nutrition from its food source (grass).

[snoop]

Sleep is part of an extremely complex homeostatic and self-preservation system, and it's clear when you begin to look at it from all sides that it has many uses, it's part of how the body can maintain itself as long as it can. Dreaming is part of memory consolidation (forming long term memories) and is a highly creative state where two unrelated things can form a connection that was never previously there. Thus, you learn while you sleep, at least during part of it, not to mention form long term memories. The brain and body have so many ways of regulating itself it's a wonder how it all came to be really. During a sleeping state you make use of different resources, it allows you to get more oxygen to vital parts of the body because you are not unconsciously hyperventilating or chest breathing rather than belly breathing. The brain has two competing sets of neurotransmitter systems, a wakefulness promoting set and a sleep..fulness promoting set. The sleep can over come the wakefulness, or simply the lack of the wakefulness can be enough to induce sleep. The neurotransmitters in the brain all work via differing mechanisms as well, some are modulatory (meaning the reduce or raise the amount of another or set of others, or even adjust the sensitivity to them). The newer ones are the more modulatory it seems. By newer, I mean they only appear in animals with higher thinking capability. For instance, worms have dopamine, but no serotonin. If there is too much stimulation in one area (aka too many neurotransmitters), how do you reduce the sensitivity? By down-regulating the number of receptors on a neuron so that it can only take in some of the neurotransmitters that are in the synaptic cleft, while enzymes such as monoamine oxidase break down the remainder, or various reuptake proteins and reuptake protein complexes bring some of the extracellular neurotransmitters back within the cell to be stored again withing a vesicle. What if there isn't enough? Up-regulate the amount of receptors on a cell. The body destroys and remakes everything because too much or too little of anything will kill you. Sleeping allows for one entire part of the brain to effectively go offline, allowing neurotransmitters to be remade after being depleted, and for any up-regulated or down-regulated cells to somewhat fix themselves as much as they can. It also puts you in a different metabolic state, and may even be key in regulating your metabolism. Then you look at your hormones, and your diet, and all this other stuff, and sometimes you need to be in a highly parasympathetic state in order not to die from stress alone. Sleeping is just that. Now the question why do we sleep for how long we do, and other animals, even, for how long they do is highly interesting. I could only begin to speculate. But if you look up things about the mind and body, the need for sleep becomes less of a mystery, in fact you wonder how beings like us could even function without it. Sleep simply makes sense.

[DreamyBear]

First of all, very interesting question JJFrank. And Snoop, very interesting post! I do agree with you Snoop that all you said make sense, and that is something I think most if not everyone like to hear about in the end. Maybe you killed some of the mystery. But there is still plenty of mystery left as I see it, and I wouldnt mind to hear you make some sense of my question aswell if you like. But if you look up things about the mind and body, the need for sleep becomes less of a mystery, in fact you wonder how beings like us could even function without it. Sleep simply makes sense. The material body know exactly how to work itself, but our aware sense of self as "I" dont know much at all. Isn't that odd? The body knows how to adapt itself, but the body is also inflicted by the "separate ego". So the less knowing ego becomes the driver, and the vehicle(the body) Is the one who give hints to the ego when it's time to stop/sleep/eat etc. And even if they are mentaly seperated by the ego, they mostly unite in the feeling of what is good. The body would probably work better all by itself, but the body stil develops a ego even if the body function perfectly the moment it's born.