Comment author: Capla 30 June 2015 11:21:42PM 2 points [-]

I am curious to what extent the info in this post is common knowledge. Are these things familiar to people?

Comment author: Mirzhan_Irkegulov 30 June 2015 08:35:35PM 7 points [-]

I'm definitely interested in subsequent posts on sleep, so please continue posting. I don't want to practice polyphasic sleep or super-optimize sleep anyway, rather just generally improve the quality of sleep, because I sleep much and still wake up feeling like crap.

I kindly ask you, however, to change the font to defaults and break paragraphs with 2 lines instead of indentation, it makes it much more readable.

Comment author: Capla 30 June 2015 10:12:07PM 5 points [-]

Better?

Solving sleep: just a toe-dipping

37 Capla 30 June 2015 07:38PM
[For the past few months I’ve been undertaking a mostly independent study of sleep, and looking to build a coherent model of what sleep does and find ways to optimize it. I’d like to write a series of posts outlining my findings and hypotheses. I’m not sure if this is the best venue for such a project, and I’d like to gauge community interest. This first post is a brief overview of one important aspect of sleep, with a few related points of recommendation, to provide some background knowledge.]

 

In the quest to become more effective and productive, sleep is an enormously important process to optimize. Most of us spend (or at least think we should spend) 7.5 to 8.5 hours in bed every night, a third of a 24 hour day. Not sleeping well and not sleeping sufficiently have known and large drawbacks, including decreased attention, greater irritability, depressed immune function, and generally weakened cognitive ability. If you’re looking for more time, either for subjective life-extension, or so that you can get more done in a day, taking steps to sleep most efficiently, so as to not spend more than the required amount of time in bed and to get the full benefit of the rest, is of high value.

Understanding the inner mechanisms of this process, can let us work around them. Sleep, baffling as it is (and it is extremely baffling), is not a black box. Knowing how it works, you can organize your behavior to accommodate the world as it is, just as taking advantage of the principles of aerodynamics, thrust, and lift, enables one to build an airplane.

The most important thing to know about sleep and wakefulness is that it is the result of a dual process: how alert a person feels is determined by two different and opposite functions. The first is termed  the homeostatic sleep drive (also, homeostatic drive, sleep load, sleep pressure, and process S), which is determined solely by how long it has been since an individual has last slept fully. The longer he/she’s been awake, the greater his/her sleep drive. It is the brain's biological need to sleep. Just as sufficient need for calories produces hunger, sufficient sleep-drive produces sleepiness. Sleeping decreases sleep drive, and sleep drive drops faster (when sleeping) then it rises (when awake).

Neuroscience is complicated, but it seems the chemical correlate of sleep drive is the build-up of adenosine in the basal forebrain and this is used as the brain’s internal measure of how badly one needs sleep.1 (Caffeine makes us feel alert by competing with adenosine for bonding sites and thereby inhibiting reuptake.)

This is only half the story, however. Adenosine levels are much higher (and sleep drive correspondingly lower) in the evening, when one has been awake for a while, than in the middle of the night, when one has just slept for several hours. If sleepiness were only determined by sleep drive, you would have a much more fragmented sleep: sleeping several times during the day, and waking up several times during the night. Instead, humans typically stay awake through the day, and sleep through the whole night. This is due to the second influence on wakefulness: the circadian alerting signal.

For most of human history, there was little that could be done at night. Darkness made it much more difficult to hunt or gather than it was during day. Given that the brain requires some fraction of the nychthemeron (meaning a 24-hour period) asleep, it is evolutionarily preferable to concentrate that fraction of of the nychthemeron in the nighttime, freeing the day to do other things. For this reason, there is also a cyclical component to one’s alertness: independent of how long it has been since an individual has slept, there will be times in the nychthemeron when he/she will feel more or less tired.   

Roughly, the circadian alerting signal (also known as process C) counters the sleep-drive, so that as sleep drive builds up during the day, alertness stays constant, and as sleep drive increases over the course of the night, the individual will stay asleep.

The alerting signal is synchronized to circadian rhythms, which are in turn attuned to light exposure. The circadian clock is set so that the alerting signal begins to increase again (after a night of sleep) at the time when the optic nerve is first exposed to light in the morning (or rather, when the the optic nerve has habitually been first exposed to light, since it takes up to a week to reset circadian rhythms), and increases with the sleep drive until about 14 hours later (from the point that the alerting signal started rising).

This is why if you pull an “all-nighter” you might find it difficult to fall asleep during the following day, even if you feel exhausted. Your sleep drive is high, but the alerting signal is triggering wakefulness, which makes it hard to fall asleep.

For unknown reasons, there is a dip in the circadian alerting about 8 hours after the beginning of the cycle. This is why people sometimes experience that “2:30 feeling.” This is also the time at which biphasic cultures typically have an afternoon siesta. This is useful to know, because this is the best time to take a nap if you want to make up sleep missed the night before.

 

http://bonytobombshell.com/wp-content/uploads/2015/05/energy-levels-sleep-drive-alert-chart-1-bony-bombshell.jpg

 

The neurochemistry of the circadian alerting signal is more complex than that of the sleep drive, but one of the key chemicals of process C is melatonin, which is secreted by the pineal gland about 12 hours after the start of the circadian cycle (two hours before habitual bedtime). It is mildly sleep-inducing.

This is why taking melatonin tablets before is recommended by gwern and others. I second this recommendation. Though not FDA-approved, there seem to be little in the way of negative side effects and they make it much easier to fall asleep.

The natural release of melatonin is inhibited by light, and in particular blue light (which is why it is beneficial applications to red-shift the light of their computer screens, like flux or reds.shift, or wear red-tinted goggles, before bed). By limiting light exposure in the late evening you allow natural melatonin secretion, which both stimulates sleep and prevents the circadian clock from shifting (which would make it even more difficult to fall asleep the following night). Recent studies have shown bright screens ant night do demonstrably disrupt sleep.2

The thing that interests me about this fact that alertness is controlled by both process S and process C, is that it may be possible to modulate each of those processes independently. It would be enormously useful to be able to “turn off” the circadian alerting signal on demand, so that a person can fall asleep at any time off the day, to make up sleep loss whenever is convenient. Instead of accommodating circadian rhythms when scheduling, we could adjust the circadian effect to better fit our lives. When you know you’ll need to be awake all night, for instance, you could turn off the alerting signal around midday and sleep until your sleep drive is reset. In fact, is suspect that those people who are able to live successfully on a polyphasic sleep schedule get the benefits by retraining the circadian influence. In the coming posts, I want to outline a few of the possibilities and (significant) problems in that direction. 

continue reading »
Comment author: Mike_Blume 15 July 2008 08:39:05AM 23 points [-]

You mentioned rationalist fiction, and my mind immediately jumped to this - are you familiar with the graphic short story "Fleep"? Main character passes out, comes to in a phone booth encased in concrete, with a phonebook full of gibberish, a letter in his pocket he can't read, a few coins and various sundries. From inside the booth he experiments and calculates, manages to work out where he is, *who* he is, what's happened, and what to do next.

Comment author: Capla 09 June 2015 12:04:55AM *  3 points [-]

Ok. I just read another comic by the same author, Demon, about a (sociopathic) character who discovers that he can't die (in an interesting way). It's great! The protagonist does exactly the sort of experimentation I would do in his situation, and several charterers make plans that are authentically clever, and legitimately surprising.

Highly recommended.

Comment author: Mike_Blume 15 July 2008 08:39:05AM 23 points [-]

You mentioned rationalist fiction, and my mind immediately jumped to this - are you familiar with the graphic short story "Fleep"? Main character passes out, comes to in a phone booth encased in concrete, with a phonebook full of gibberish, a letter in his pocket he can't read, a few coins and various sundries. From inside the booth he experiments and calculates, manages to work out where he is, *who* he is, what's happened, and what to do next.

Comment author: Capla 08 June 2015 09:03:53PM 1 point [-]

That was fantastic!

Comment author: Dan 23 November 2007 07:55:15AM -1 points [-]

Most apples aren't good to eat. Only those specifically bred for such purpose.

In response to comment by Dan on Leaky Generalizations
Comment author: Capla 01 June 2015 09:05:45PM 0 points [-]

Aren't most of the apples on earth precisely the ones we bread to be edible (and tasty)?

Comment author: Jiro 04 May 2015 02:28:38PM 2 points [-]

People shooting other people with blaster rifles and flying spaceships sounds cool too.

Comment author: Capla 09 May 2015 08:30:23PM 0 points [-]

I'm not sure what your point is?

Comment author: Gunnar_Zarncke 06 May 2015 09:39:46PM 2 points [-]

I think people acquire a belief that a post or comment of a certain felt quality deserves a rough number of upvotes or downvotes, so they don't add or subtract karma when the post or comment hits that level.

Sounds familiar and could indeed explain why some posts do not continue to accumulate votes after some time.

Let's check:

I think a post deserves a certain number of votes/karma and up/downvote accordingly

Submitting...

Comment author: Capla 06 May 2015 10:26:14PM 6 points [-]

I generally don't care what level a post is at if I'm going to upvote it, but when I see something has a negative core that I think is unfair, I'll bump it up by one.

Comment author: jacob_cannell 29 April 2015 07:08:57AM 1 point [-]

I mean that the physical information which defines - or alternatively is required to reconstruct - a human mind is not strictly localized in space to the confines of a single brain.

Using the hardware/software analogy, the brain is the hardware, the mind is the software, but the mind is distributed software: each mind program runs mainly on a single brain, but it also has partial cached copies distributed on other brains.

For example, if two people spend a bunch of time together, they are going to have many shared memories. Later if both die and the brain of one is preserved, the shared memories are useful for constructing both minds. With many preserved brains, you get multiple viewpoints for many overlapping memories which allow for more precise reconstruction.

Comment author: Capla 06 May 2015 09:19:09PM 0 points [-]

I'm a little disturbed by the thought of reconstructing my personality from others' impressions of my personality.

Comment author: Gondolinian 01 May 2015 06:04:30PM 13 points [-]

There is a not necessarily large, but definitely significant chance that developing machine intelligence compatible with human values may very well be the single most important thing that humans have or will ever do, and it seems very likely that economic forces will make strong machine intelligence happen soon, even if we're not ready for it.

So I have two questions about this: firstly, and this is probably my youthful inexperience talking (a big part of why I'm posting this here), but I see so many rationalists do so much awesome work on things like social justice, social work, medicine, and all kinds of poverty-focused effective altruism, but how can it be that the ultimate fate of humanity to either thrive beyond imagination or perish utterly may rest on our actions in this century, and yet people who recognize this possibility don't do everything they can to make it go the way we need it to? This sort of segues in to my second question, which is what is the most any person, more specifically, I can do for FAI? I'm still in high school, so there really isn't that much keeping me from devoting my life to helping the cause of making sure AI is friendly. What would that look like? I'm a village idiot by LW standards, and especially bad at math, so I don't think I'd be very useful on the "front lines" so to speak, but perhaps I could try to make a lot of money and do FAI-focused EA? I might be more socially oriented/socially capable than many here, perhaps I could try to raise awareness or lobby for legislation?

Comment author: Capla 06 May 2015 09:12:45PM 1 point [-]

which is what is the most any person, more specifically, I can do for FAI?

First thing you should do is talk to the people that are already involved in this. CFAR seems to be the gateway for man people (at least, it was for me).

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