I had 3 hours of sleep last night but strangely I feel fine. The night before last I had jus 5 hours. Maybe I don't require as much sleep anymore. I read a research once you can train yourself to require less sleeping time. It is normally done by reducing the prep stage of sleep time people wasted. Since supposedly the point of sleep is really the REM stage where you do most of the dreaming.
Here is a really long piece of writing summerizing 5 stages of sleep and then describing how to shorten your need for sleep. This is mostly a little note to myself and reading it will mostly likely put you to sleep.
Here is how sleep works. There are 5 stages of sleep, which together form a cycle. Each cycle lasts 90 to 120 minutes. Each night most people undergo 4 to 6 cycles. So the interesting thing here to note is that not all sleeps are equal. The most restorative stage of sleep is the 5th stage where REM occurs. This is also when the majority of your dreams occur.
The process of dreaming has a high correlation to memory retention. Your short-term memories are processed during the REM (5th) Stage then become long term. The theory is that REM dreaming helps consolidate spatial and procedural memory by cross-referencing your life experiences.
5 Stages of Sleep:
Stage 1: 5~10 minutes, it is a transitional period between waking and sleeping. When people shift restlessly, it is during this stage. There is a 50% reduction of your alpha brain wave compare to waking at this stage. Interestingly, a rare condition known as Hypnagogic hallucination happens in this stage.
When in a hypnagogic state a person can have lifelike auditory, visual, or tactile hallucinations (known as hypnagogic hallucinations), perhaps even accompanied by full body paralysis. The paralysis is the result of natural nerve signal block to prevent a sleeper from moving their body during REM stage. Sleep walking and sleep talking is due to inadequate paralysis and the dreamer is simply acting out their dream.
During hypnagogic the individual is aware that these are hallucinations; the frightening part, in many cases, is the inability to react or make a sound because REM paralysis has kicked in. In other cases one may enjoy truly vivid imaginations. The term was coined by the 19th century French psychologist Alfred Maury. Many artists, musicians, architects, engineers, and others demanding creativity to be successful have benefited from the hypnagogia state, where the mind can be totally free and open to creative and new ideas.
Now hypnagogic happened twice in my life. One induced a wonderful and joyous emotion which I can only categorize as a religious experience. The other one induced my single most horrifying experience which I would really rather not think about again - However I would elaborate that it involves auditory hallucination and partial paralysis. Strangely neither experience resulted any creative ideas. However, both have definitely shaped part of my character. Which is amazing when you consider that both experiences lasts less than 5 minutes of my life. About 30-40% of people will experience hypnagogic hallucination once in their life.
Full paralysis happened once in my life. Paralysis occurs when you go into REM nerve blocking stage too fast, as in the case of hypnagogic. Or, it can occur at the end of a sleep when you get out of REM too fast. Your brain didn't have a chance to unblock the nerve but you are already awake. This is the case with my waking paralysis. Chinese old lore refers to this phenomena as "Ghost pressing down on one's body" in order to explain why one can't move. 60% of people will experience this once in their life.
Since hypnagogic means that you retain your consciousness while sleeping, it is more often coined as "waking dream", even though at this stage you are not dreaming yet. Lucid Dreamers train themselves to recognize hypnagogic stage, so they remain "awake" then transition into REM sleep. Effectively, they can consciously control their dream and its elements. This technique is called Waking Induction of Lucid Dreaming (WILD). I am not making this up, someone thought it is a good idea to call this crazy technique WILD with no thoughts of how people might think about creditability. The other technique to induce lucid dreaming occurs inside your dream. You train yourself to recognize some signs that you are not in the real world. This can happen when you see something that is impossible and proceed to reason out that you are in a dream. Once recognizing it is a dream you then can consciously alter it. This second technique is called Mnemonic Induction of Lucid Dreaming (MILD).
There are a couple ways for MILD to occur and this is the one you most likely have experienced. Usually when sleeping people take bizarre occurrences as normal. Yet sometimes event occurred that is against your deep belief of what is natural and you proceed to reject the dream as reality. Psychologically, MILD occurs more on an unpleasant dream, people tend not to question a happy dream no matter how absurd it might be. Also, trained Lucid Dreamers can set signs. If the dreamer see his unique sign then he would realize it is a dream.
While WILD never happened for me, MILD has occurred on several occasions. Once I dreamed I smelled a skunk in a library. For some reason that struck me as totally against everything, which is good, right, and true (please don't ask my reasoning, I really don't know). The thought I had at the moment was that "There can never be a skunk in the library! Never!" Maybe I think of library as sacred subconsciously - I really don't know. The result is that I realize I was dreaming and I proceed to explore the world and I added a streetlight to the front of the library (again, please don't ask me why, I thought it was a good idea at the time). The concept of The Matrix is closely related to Lucid Dreaming. The search for reality and truth is equally blurred on both cases. Really, how do you know our lives aren't just one big dream?
Stage 2 - You are now unconscious but can still wake up easily. Your brain wave will show sleep spindles and K-complexes at this stage.
Stage 3 - Delta wave begins to form and comprise of 20% to 50% of your brain wave. Dreaming can occur here but it is more rare. Dreaming frequency is related to delta wave, also known as slow wave sleep.
Stage 4 - Delta wave made up of over 50% of your brain wave. Parasomnias, also known as sleep walking, commonly occur at this stage. Stage 1, 2, 3, and 4 are referred to as Non-Rapid Eye Movement (NREM) part of cycle. Chances of dream increases from stage 3 although vastly less than Stage 5.
Stage 5 - Rapid Eye Movement (REM) Sleep. Supposedly this is where the good stuff happens. Dreams occur most frequently at this stage, you gain long-term memory, and your immune system gets a boost.
Yet I could find nothing concrete from creditable academic sources. Every source that praises REM sleep is from the Internet that looks like a personal web page, non-edu web page, or blogs. Academic papers, published books, and encyclopedia paint a slightly different picture.
First, for example, actual studies have shown no measurable memory difference with people who doesn't have REM stage due to brain damage compare to people who REM. Therefore I have doubts on a direct relation between REM and memory retention.
Second, REM deprivation makes a person happier.
Recall that for REM sleep the body blocks nerve signals. The body does it by shutting down monoamine, a neurotransmitter. One "theory suggests that monoamine shutdown is required so that the monoamine receptors in the brain can recover to regain full sensitivity. Indeed, if REM sleep is repeatedly interrupted, the person will "make up" for it with longer REM sleep at the next opportunity. Acute REM sleep deprivation can improve certain types of depression, and depression appears to be related to an imbalance of certain neurotransmitters. Most antidepressants selectively inhibit REM sleep due to their effects on monoamines, however this effect decreases after long-term use."
Third, your immune system is not actually boosted during REM stage either. The boost happens during NREM phase.
"...it turns out that when animals are sleep deprived, a protein known as di-muramyl peptide accumulates in their spinal fluid. The peptides do not originate in the brain. Instead, they come from bacteria in the body, suggesting that sleep deprivation may enable bacterial growth and that sufficient sleep impedes bacterial growth.
What's even more interesting is that these di-muramyl peptides enhance NREM sleep but not REM sleep... More interesting still is the fact that the peptides stimulate cells in the brain and the body to produce interleukin-1, a powerful immune-system molecule that promotes the destruction of both bacteria and tumor cells. Highly significant and desirable health effects are mediated by interleukin's ability to encourage the B lymphocytes to produce antibodies, which kill viruses, and to trigger the proliferation of T lymphocytes, which attack microbial invaders. The net effect is to mobilize the body's defensive forces."
To summarize, lack of sleep decreases immune system so bacteria grows -> bacteria produces di-muramyl peptide -> the harmful peptide stimulates production of interlukin-1 -> Interlukin-1 stimulates B lymphocytes to produce antibodies and triggers the proliferation of T lyphocytes -> B antibodies kill viruses and T attack microbial invaders.
Notice interlukin-1 is also a sedative. So it induces sleep. The cycle is simple and elegant.
Lack of sleep causes low immune system -> immune system goes into overdrive to balance overgrown bacteria and also induces NREM sleep -> induced NREM sleep means lack of sleep is cured -> Enough sleep means immune can now operate normally again.
A major reason our body doesn't encourage REM to regain sleep and immune system is because we loose body temperature control at REM stage. If you are already sick and fluctuating in temperature it would be a bad idea to give up body temperature control. When you are sick NREM sleep is the way to go.
So why do people say REM sleep is such miracle? Because while memory retention is not solely related to REM, it is largely related. We dream twice as much in REM sleep compare with NREM. Also the firing rate of our neurons during REM sleep is half that of NREM, meaning we dream twice as much while using half as much energy. On top of all that, out of 8 hours of your sleep, 90-120 minutes of that is REM. Yes, in 2 hours you dream twice as much as you do than the other 6 hours. To put it plainly, REM is 6 times better than NREM when it comes to memory.
So the theory of training yourself to sleep less is a trade off between REM and Immune System. In theory, "3 hours of REM sleep" = "2 hour of REM + 6 hours of NREM". Assuming you are healthy, you can sleep 3 hours indefinitely. You gain 5 hours a day with a slightly lower immune system.
Practically though, a person who seriously want to do this long term would have to spent at least an hour a day exercising to increase body health and immune system. Technically then you only gain 4 hours of "free" time. But as we can see, it is not free. The training takes about 2 months and requires both discipline and will few people possess. Further more, whenever you are sick, the body will force NREM sleep on you and only a fool will continue 3 hour sleep routine while sick. However the breaking of the routine means that it will take another training period to adjust your sleeping routine. It takes 3.5 days of training ratio to 1 sick day to re-adjust your sleeping pattern.
So how does it work? You kick into REM sleep quicker when you are sleep deprived. On sever cases of sleep deprivation people can actually hit REM in minutes. Such practice is obviously dangerous and not beneficial. You don't run a marathon when you have sit in the office for 30 years. You start by walking, then jogging, then long distance. Same thing with sleep, you are stretching your metaphoric REM muscle. If you usually sleep 8 hours, go to bed an hour earlier at 7. Do that for 7 days then take another hour off. So in 21 days, you will be trying to sleep 5 hours a day. Now take off 30 minutes every 7 days for 28 days until you hit 3 hours a day.
It is not recommended to go under 3-hour sleep for any length of time.
Of course, everyone is built differently. Just like not every can be made to run a marathon. Once under 5 hours, you should check at the end of 5th day for warning signs that you have reached your limit. Shortness of breath, insensitivity to cold, your ear somehow feels warmer than normal (especially the tip of your ear), short attention span, noticeable worsen memory, and if you have problem falling asleep (yes, supposedly it happens, it is known as a rebound). Once one or more signs shows, you should stop decreasing sleep time. If after another 5 days the sign(s) still persist, you should add an hour to your sleep time.
In reality, changing your sleeping habit is as easy as changing the way you breathe. Which is to say, very hard. You can change your breathing pattern for a short length of time consciously, but unless fundamental changes occur that touches the way you act subconsciously the change won't last. It is the same thing with sleep. You might be wondering why would any one want to breath different. But how breathing deeper might be good for you might be a bit off topic at the moment for this already long piece of writing.
*Thoughts on related article: Body temperature control, Art of breathing.
Hypnagogic Hallucinations: http://en.wikipedia.org/wiki/Hypnagogic_hallucination
Lucid Dreaming: http://en.wikipedia.org/wiki/Lucid_dreaming
Sleep and the Immune System: http://www.banned-books.com/truth-seeker/1995archive/122_2/ts222e.html