Claudio Stampi tested all the various forms of reducing sleep and found polyphasic - the uberman style - to be the best out of them all.
At the same time, he found that polyphasic sleep results in poorer performance compared to normal sleepers. And this was considered non-noteworthy, since obviously 2 hours of sleep is worse than 8. You can find his articles on Google Scholar.
Steve Pavlina is the only person I know of who has claimed to be polyphasic for an extended period of time and claimed that there is no performance decrease. Unfortunately, Steve refused to do any scientific testing and relied entirely on his own subjective judgment. He gave it up after 6 months anyway, but still maintains it is effective.
Steve's Pavlina's experience however exactly fits in with the best scientific understanding of sleep (which Wozniak perfectly elucidates). Steve Pavlina was never able to maintain the schedule without an alarm clock, which indicates that his body did not adapt and was not co-operating or behaving in a "natural" way.
The theory that Steve was only getting REM is shot down by his own journals which indicate that he was getting both Delta and REM. My own experience with polyphasic also indicates that while the proportion of REM may increase, you still get delta sleep. I was fully (and rigidly) polyphasic for some weeks but never stopped having delta sleep. I also consistently showed decreased performance that could only be overcome by surges of adrenaline and autonomic excitation in general - which is easily caused when a loud alarm clock wakes you up when your body desperately desires sleep. You are tricking your body into a state of permanent fight or flight.
Anyway the studies were done in the 80s that directly measured performance. But in the modern day extensive studies have been done on sleep and everything we know about sleep now shoots down all the theorizing that the polyphasics use to justify their crazy. The idea that delta wave sleep is useless has been utterly rejected because it has been shown that delta wave sleep contributes to long-term memory encoding. If you cut down on delta wave, you cut down on long-term memory. If you cut down on sleep in general, you cut down on cognitive abilities in general.
This trade off may be worth it for some people, but they should be aware that it is a trade off. Magical thinking like that displayed by Steve Pavlina does not magically make you immune from the negative side effects of sleep deprivation. You get over the drowsiness with sheer strength of will and adrenaline, but the fogginess doesn't go away. (Steve considered the fogginess to be a benefit. But remember this is a guy who believes ghosts tell him how to win at blackjack.)
So, talking about this and reading what links I could find from your originally linked article, as well as reading up on Claudio Stampi leaves me no more illuminated. Stampi's book Why We Nap is out of print, my library does not have a copy, and I can't find any other references to actual studies that prove the arguments against polyphasic sleep, though the opinion of most folks does seem to be that it's not a replacement for a full nights sleep. I just can't figure out how they know, rather than merely think so. There seems to be a tremendous amount of regurgitation of party lines and mentioning of the same few, mostly dubious, sources. I think damned near everybody involved in the conversation, including you and I, understands less about sleep than they think they do.
You're right, however, that there is a cult-like feeling around polyphasic sleep discussion, and I view that sort of thing with extreme skepticism...but I'm surprised to find it happening on both sides. The "debunkers" are just as guilty of making unbacked claims, and poorly citing their opinions.
Every time I've seen a straight up assertion about how long one should sleep, whether napping can reduce the total number of hours needed, etc. I'm unable to find a study that directly backs the assertion. I guess such studies must exist, but no one is linking to them. Even Wikipedia is surprisingly lacking in citations of directly relevant scientific research on the matter.
SwellJoe, I'm with you in that the "debunkers" seem quite dogmatic. Then there are people who have had personal success with polyphasic sleep and rave about it, typically doing it for a period of months but not on a permanent basis. Science doesn't have a lot to say, and everyone else is left wondering what to think.
References I found enlightening about the actual practice of it (in favor of it) are the book Ubersleep:
I've read enough anecdotal evidence to be convinced that when it polyphasic sleep works, it works -- that after a potentially rough (and potentially impossible, depending on the person) period of adaptation, the practitioner is not significantly impaired in day-to-day functioning. Skeptics' arguments usually boil down to "it's unnatural", "you can't get something for nothing", or "it didn't work for me".
In terms of needing to set an alarm, I don't know if the body can learn a polyphasic schedule or not; even if it can, the reasons busy monophasic people use alarms to regulate their sleep would apply all the more so to polyphasic sleepers, and I get the sense polyphasic sleep is a sort of "unstable equilibrium"; and if the body can't learn it, that still doesn't mean it's unnatural.
Science could come along and discover a long-term deleterious effect of getting so little sleep, in which case I'd be all ears, but it seems doubtful. I hope the science catches up, though, and we figure out what the deal is with sleep, so we don't have to argue quite so irrationally. There's a lot of interesting recent work on whether being unconscious for eight hours is mostly a behavioral adaptation rather than a biological necessity.
My general philosophy is "if it works, do it", and it definitely works in some instances. Reducing total time spent sleeping per day isn't like smoking cigarettes, it isn't going to slowly poison you. Lots of people get very poor sleep and are definitely impaired during the day, more so than a skilled polyphasic sleeper would report, and they aren't doing long-term damage.
The debunkers are cultish because the proponents are cultish. Just like atheists are cultish in response to cultish cults.
If reducing delta wave sleep by 10% significantly decreases performance on memory and reasoning tests, why should reducing delta sleep by 90% fail to decrease performance?
Lots of studies are done on sleep, but they are never as extreme as polyphasic because it would be considered unethical to perform those studies. Those few insane people like me who actually did go polyphasic don't get scientifically tested.
It did work for me but I recognized that my performance had decreased because at the time I was in memorization-oriented schooling and using Anki to manage my memorization tasks. With the help of Anki, I could see quite clearly that my memorization abilities had decreased.
It was also never a natural state. It was a constant state of heightened autonomic response - fight or flight. Especially at nighttime, my body was surging with corticosteroids. This stress response is what provides the capability to stay awake so long, but it comes at the price of high-level thinking and memorization.
Typically in nature, humans will adopt polyphasic sleep in times of war and other extremely stressful situations. This is adaptive because their life is threatened. This is not the case for the modern knowledge worker.
There is tons of science on sleep. The polyphasic people base their theory on the outdated and discredited idea that we only need REM sleep. This has been categorically disproven by modern sleep researchers. Slow wave sleep provides many benefits, the most clear being improved memory but also better performance on other cognitive tasks.
AFAIK Claudio Stampi is the only person to test polyphasic directly because since then it has been considered unethical to directly test polyphasic. (The Geneva Convention considers it torture, afterall)
At the same time, he found that polyphasic sleep results in poorer performance compared to normal sleepers. And this was considered non-noteworthy, since obviously 2 hours of sleep is worse than 8. You can find his articles on Google Scholar.
Steve Pavlina is the only person I know of who has claimed to be polyphasic for an extended period of time and claimed that there is no performance decrease. Unfortunately, Steve refused to do any scientific testing and relied entirely on his own subjective judgment. He gave it up after 6 months anyway, but still maintains it is effective.
Steve's Pavlina's experience however exactly fits in with the best scientific understanding of sleep (which Wozniak perfectly elucidates). Steve Pavlina was never able to maintain the schedule without an alarm clock, which indicates that his body did not adapt and was not co-operating or behaving in a "natural" way.
The theory that Steve was only getting REM is shot down by his own journals which indicate that he was getting both Delta and REM. My own experience with polyphasic also indicates that while the proportion of REM may increase, you still get delta sleep. I was fully (and rigidly) polyphasic for some weeks but never stopped having delta sleep. I also consistently showed decreased performance that could only be overcome by surges of adrenaline and autonomic excitation in general - which is easily caused when a loud alarm clock wakes you up when your body desperately desires sleep. You are tricking your body into a state of permanent fight or flight.
Anyway the studies were done in the 80s that directly measured performance. But in the modern day extensive studies have been done on sleep and everything we know about sleep now shoots down all the theorizing that the polyphasics use to justify their crazy. The idea that delta wave sleep is useless has been utterly rejected because it has been shown that delta wave sleep contributes to long-term memory encoding. If you cut down on delta wave, you cut down on long-term memory. If you cut down on sleep in general, you cut down on cognitive abilities in general.
This trade off may be worth it for some people, but they should be aware that it is a trade off. Magical thinking like that displayed by Steve Pavlina does not magically make you immune from the negative side effects of sleep deprivation. You get over the drowsiness with sheer strength of will and adrenaline, but the fogginess doesn't go away. (Steve considered the fogginess to be a benefit. But remember this is a guy who believes ghosts tell him how to win at blackjack.)