synapse renormalization - another reason to sleep more than minimum-REM

post by Jonathan_Graehl · 2011-08-21T19:44:37.093Z · LW · GW · Legacy · 11 comments

(not yet studied in mammals)

The ratio of the strength of a synapse between neurons and the total potential (from all incoming synapses) needed to activate a neuron may be all that figures; the absolute values may not be important (this is the basis for computer neural networks, though temporal effects, firing rates, and who knows what else also matter in real brains).

So you can renormalize (multiply by some constant 1) and see almost no difference except for perhaps greater susceptibility to noise. But at least the amount of physical material needed is smaller, and the energy needed is smaller. It's more efficient.

In flies and other simple animals studied so far, this definitely happens during sleep. Maybe it happens in humans also. (remains to be studied).

In any case, be careful committing to some REM-sleep only 3hr/day-with-naps sleep schedule, just because you may feel fine at first, when the exact utility of non-REM sleep isn't completely known.

Via.

11 comments

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comment by Vaniver · 2011-08-21T23:02:54.566Z · LW(p) · GW(p)

Is there a reason to believe that synapse renormalization happens in a non-REM stage of sleep, rather than a REM stage of sleep?

Replies from: Jonathan_Graehl
↑ comment by Jonathan_Graehl · 2011-08-22T07:14:58.316Z · LW(p) · GW(p)

I also noticed the lack of evidence for this. The claim was made by the person writing about the study (link at bottom). He seemed relatively expert in the domain, so I didn't worry about it.

I guess it seems more plausible to me that renormalization might occur when the brain is quiet (otherwise, the mechanism might need to be slightly more complicated, to suppress or ignore activity where it acts - pure speculation on my part). But some sleep cognition definitely occurs outside of REM. So on the whole I weigh it as "further study needed" - especially since this is so far in flies only.

comment by [deleted] · 2011-08-22T13:50:29.792Z · LW(p) · GW(p)

I've always wondered whether or not modafinil (provigil) or other drugs are effective for long-term avoidance of sleep without major side effects. Does anyone on LessWrong have experience with modafinil that they would be willing to talk about? (PM if you would prefer not to discuss publicly).

I enjoy the feeling of sleep because my primitive mammal brain needs it, but on an intellectual level I hate every hour that I give over to sleep. It feels too much like death because of its unavoidable encroachment. All too often I'm not ready to surrender the hours to sleep that could be spent learning, or reading, or anything else that I want to do instead. I also hate the tiredness that I'm punished with when I try to steal a few hours from the night. The tiredness persists for most of the day and prevents me from doing any serious work if bad enough (coffee can bring me out this, but it wears off and is not a good long term 'solution' to sleep).

Anyway, to be more on-topic, I would not be surprised (but disappointed) if sleep were far more necessary and needed than a quick first-pass would show. Its omnipresence throughout the animal kingdom (a form of sleep can be observed in a freakin' nematode#Sleep_in_invertebrates)) as well as the fact that we don't observe any full exceptions to the requirement of sleep suggests that it is not trivial for life as we currently know it to evolve away from needing it.

Replies from: shokwave
comment by Alex_Altair · 2011-08-22T01:33:08.738Z · LW(p) · GW(p)

My stance on polyphasic sleep is one of self-experimentation. It seems that sleep is still largely a mystery, and therefore if I can manage to sleep on a polyphasic sleep schedule and gain 6 hours of life every day, I'll risk it. Of course, this will all change soon when we discover more details about sleep (including this one). Also my experiences with polyphasic have all failed. Thanks for the article!

Replies from: Jonathan_Graehl
↑ comment by Jonathan_Graehl · 2011-08-22T07:16:10.639Z · LW(p) · GW(p)

Gaining 6 hours per day seems very extreme. However, I wish you luck in your future trials.

Replies from: Alex_Altair
↑ comment by Alex_Altair · 2011-08-22T20:19:00.966Z · LW(p) · GW(p)

Thanks, although my experimental phase is over, ending in full failure, unless I hear more evidence in the future.

Replies from: Xachariah
↑ comment by Xachariah · 2011-08-23T04:24:55.893Z · LW(p) · GW(p)

I successfully (?) did polyphasic sleep for several months before quitting during the summer between graduation from highschool and college. I've made multiple attempts after that, all of which failed though usually for social reasons.

After the initial adjustment period I suffered no ill effects and even felt healthier, although I would attribute that to having nothing to do at 4 AM except workout and a strictly regimented eating schedule (I had to abandon meals and eat once each wake period). If I had a schedule that permitted it and friends/family/girlfriend that were supportive instead of sabotaging, I would gladly pick up the schedule again

Anecdote, but hopefully useful to you.

Replies from: Alex_Altair
↑ comment by Alex_Altair · 2011-08-24T02:05:00.983Z · LW(p) · GW(p)

Awesome! Which schedule did you use? How were you able to not fall asleep during the transition period? Did you do it with a friend? Did you blog it?

(Sorry if this is too many question. The potential of 37% more life makes me REALLY excited.)

Replies from: Xachariah
↑ comment by Xachariah · 2011-08-24T11:28:33.777Z · LW(p) · GW(p)

I used Uberman with 24 minute sleep periods and a 2 minute fall asleep window. I'd sleep 6 periods in the day every 4 hours on the hour: 2 am, 6 am, 10 am, 2 pm, 6 pm, 10 pm. Staying awake was not an issue past the initial acclimation period. I'd feel just as awake at 4AM as I do during the middle of the day; though I've always been a night owl. My biggest struggles always came from trying to 'cheat' (skip a period, or push it back) and getting off schedule by being too tired and thus oversleeping the next period.

I think what allowed me to succeed was that I partitioned my day into 6 separate days consisting of 4 hours (240 minutes) instead of 1 day consisting of 24 hours.

  • 1-26: Sleep

  • 27-60: Do one of 3 groomings (brush teeth, shower, or shave/nails/facial) and eat 1/2 a meal

  • 61-180: Perform my productive work for the 'day'. Eg working out, work around the house, go out shopping, programming, etc.

  • 181-240: Relax. Usually in the form of watching something, socializing, or reading. (I quickly learned Videogames would leave me too restless to sleep immediately after and would push back my sleep schedule, so they would have to go into the productive period if I wanted to partake.)

My girlfriend assisted me in waking up for those hours she was awake for, though she didn't attempt the schedule herself. I imagine it would have been much easier if she had. Waking up at 2 and 6 AM was hard as hell; for those I wouldn't be able to sleep in my own bed (since any alarm would wake her) so I used college alarm clock and slept near my computer. (NB: Haven't checked that download, it's the second google hit and looks like the one I used though.)

I was doing it back before blogging was popular, although Mr Pavlina's blog is a very, very similar description (though he adapted much more quickly than I did). Unlike him I do still fancy going back to the schedule once I'm self employed and can convince my current girlfriend that it's not unnatural. However, I've tried multiple methods (like Everyman) to make it work, but my reasons for quitting and never stably returning echo his exactly, "The rest of the world simply isn’t polyphasic."

comment by gwern · 2012-04-03T16:19:49.713Z · LW(p) · GW(p)

Somehow I missed this the first time; but recently I came across the concept for my Algernon's law essay and dug up 2 PDFs: