Do you think that the sleep-dep effects might be worse for learning/information-retention tasks than work purely for concrete results?

That's exactly what I do when I just NEED to get stuff done! A lot of people say that they can work for 20+ hours, well I can't, I feel super tired and can't think after 6-7 hours, BUT then I take 30-90 minutes of sleep and I feel like I slept a full night - back to work for another 6 hours, then sleep again (3-4 hours if it's 5 am :-) and so on.

I did it this past week, and today, after sleeping 9 hours straight, I woke up thinking "Wow, that was a long month!". It really feels like I've been working for a full month - not only that, but I got a month's worth of work done in a week! It's pushing the brain and body to the limit (after about a week, I just crash), but I sure wish I could do it every single day of my life... I can think, work AND LEARN (@Nathan) faster and better - it's like I switch from my Jeep to a F1 car :-)

There's some pretty good evidence that being tired/underslept is bad for memory and retention.

On the other hand, our memory and retention of passive learning is pretty bad anyways, so if you were taking action on what you're learning in the time you're not sleeping, I bet it'd be a net gain.

Really depends on the subject and the person though. Definitely wouldn't want to undersleep if you were doing "pure learning" without any action - studying for a comprehensive licensing exam or some such. For hands-on learning, I think minor amounts of lowered sleep would be okay, maybe even a net gain.

Of course, again, I don't think it's sustain for the long term. A few weeks, maybe a couple months max, and then your body is going to start gradually rebelling against you.

Oh *man* do I miss being able to do that.

Small children plus regular job schedule equals no. But it's *so* much fun :-)

There was a strategy I read about somewhere of sleeping 6 hours, then being active for another 6 - repeat as many times as needed. You get the equivalent of two days active time AND you sleep good hours. I haven't tried it or studied possible effects, but it sounds healthy enough for my taste and it's promising in terms of productivity.

I used to use polyphasic sleep all the time when I was in college, and it worked really well for me. The biggest problem was getting the sleep durations and spacings dialed in just right. Eventually, with enough trial and error, I found a 'sweet spot' where I was only sleeping about 3.5 hours per day with little to no negative side effects (after the first 4 or 5 days). I should note that I only did it in short-term - no more than 3 weeks at a time usually - and the first few days of a cycle can be rough and disorienting.

It spaced out roughly like this:
7 a.m. - 25 min nap
11 a.m. - 25 min nap
3 p.m. - 25 min nap
7 p.m. 25 min nap
12 a.m. - 120 min sleep

The new Tim Ferriss book, The 4 Hour Body, has a short (but good) section on polyphasic sleep. It would have saved me a lot of experimentation if it had been published 5 years ago - worth checking into if you're interested in polyphasic sleep and the science behind sleep patterns.

I'm trying to get some info on how polyphasic sleep works for people in different majors -- what was your major?

My major was in Accounting with a minor in Philosophy / Religion Studies. If I had a lot of work to do I'd switch what I was working on after a 25 min nap like this:
2 hr sleep
2-3 hrs. accounting study / homework
snack
25 min nap
2 hours philosophy reading / paper writing
light breakfast
25 min nap
1 hr accounting
daily chores / routine / email / etc
snack
25 min nap
study time on whatever I had left to do
dinner

That's roughly it - I forgot to mention in the original comment that I also found the 2 meal, 2 snack schedule to be best for this sleep routine. High quality carbs like oatmeal were a big help in fighting fatigue and good protein. Kind of like a workout diet except I never went to gym while experimenting with sleep.

It took me three or four trials before hitting the sweet spot combo of sleep schedule and diet - I probably have all my notes on this saved on a flash drive if you're interested.

Great comment.

> I probably have all my notes on this saved on a flash drive if you’re interested.

You can mark me down as interested, I'd love to learn more! Maybe a blog post on your site?

A post is a better idea than sending out and having to explain my notes. I'll track down the files and get something put together for my site - hopefully in the next week or so.