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Comment by jimnotgym | Hacker News Reader

I had a purely practical issue with "Why we sleep". The book says multiple times that you cannot run a sleep deficit and then make it up later. So what should I do if I have run a deficit? If the deficit reduces cognitive function, and I can't make it up with more sleep, does it follow that for every short nights sleep I will have a permanent reduction in cognitive function? If I turn my alarm off and let my body decide it makes me sleep for longer after a deficit, is my body wasting its time?

It doesn't feel like this can be 100% true

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The book is best viewed as a lot of well-meaning exaggerations that are, nonetheless, exaggerations.

The author really, really wants people to take sleep seriously, so he stretches the truth as much as possible to make sleep sound gravely important. He's writing to sell books and spread his message, not necessarily to win awards for posting accurate research.

> If the deficit reduces cognitive function, and I can't make it up with more sleep, does it follow that for every short nights sleep I will have a permanent reduction in cognitive function?

Obviously, the short-term cognitive deficits of sleep deprivation are reversed upon sleeping again.

It's likely that some amount of long-term damage occurs when engaging in unhealthy activities like losing sleep, but the amount of damage is only significant when sustained over long periods of time.

Think of like drinking alcohol: Drinking a bottle of wine in a night is not a healthy activity, but doing it a couple times a year will have negligible impacts on your health. However, drinking a bottle of wine every night for many years in a row will start to produce measurable effects on your liver, among other things.

Sleep deprivation is similar. Missing a night of sleep isn't going to shorten your lifespan or doom you to early cognitive decline. However, depriving yourself of sleep for years on end is likely to produce some negative effects over time.

> The author really, really wants people to take sleep seriously, so he stretches the truth as much as possible to make sleep sound gravely important.

Not very ethical. But understandable.

> He's writing to sell books and spread his message,

...and arguably that turns it into fraud. If not for the misrepresentation of the facts, would I have bought his book?

>> He's writing to sell books and spread his message,

> ...and arguably that turns it into fraud. If not for the misrepresentation of the facts, would I have bought his book?

Not to be overly-pedantic, but I think knowingly exaggerating the truth to sell books is more of a scam than a fraud. To me, fraud is closer to outright deception than exaggeration. Fraud is also better defined. Laws are written about fraud. Fraud, I think, is a weightier charge of duplicity.

I base this only on my own internal reaction to the words. Here’s someone getting more into the lexicon:

> In short, scam has no legal status as a term of law in most jurisdictions, except insofar as it may be defined as a type of fraud. The term fraud is broad but usually very carefully defined in statutory law.

https://english.stackexchange.com/questions/348183/whats-the...

Interesting! I didn't know there was a distinction in law between those two terms. I think your definition of "scam" is closer to what I was trying to get at.

I think that page supports the notion that it's fraud. People pay with money for the book because of its claims. The legal dictionary says:

FRAUD. An intentional perversion of truth for the purpose of inducing another in reliance upon it to part with some valuable thing belonging to him or to surrender a legal right; a false representation of a matter of fact, whether by words or by conduct, by false or misleading allegations, or by concealment of that which should have been disclosed, which deceives and is intended to deceive another so that he shall act upon it to his legal injury.

It's a pretty broad definition. Certainly a strong case could be mounted that this fits, however, academics are basically never prosecuted for fraud and there would be enormous institutional resistance to doing so, given the prevalence of fraud in the research literature.

> Sleep deprivation is similar. Missing a night of sleep isn't going to shorten your lifespan or doom you to early cognitive decline. However, depriving yourself of sleep for years on end is likely to produce some negative effects over time.

You have citations to support this? Or are you just recycling Walker’s claims with slightly less exaggeration?

Perhaps I should be more intellectually vigilant but this claim strikes me as so likely to be true that I wouldn’t bother trying to find a citation for it.

In my experience, the people who are frequently sleep deprived for a few years don't seem to be worse for it afterward.

My main sources of anecdote for this are grad school students with hectic school and advisor setups (who often are partly sleep deprived for much of 3+ years), and parents who have several children in short succession (ensuring their sleep is ruined for roughly 2 years).

In neither case do those groups seem to suffer significant long-term effects that are obviously from the sleep deprivation.

> this claim strikes me as so likely to be true that I wouldn’t bother trying to find a citation for it

This seems to be the source of just every factoid. You took something that just sounds true to you and made it into an objective statement.

I didn’t make it into anything and I don’t take it as axiomatic, I just wouldn’t spend time looking it up. It also sounds true to me based on my knowledge of biology, upon which I get to draw inferences I think are reasonable.

I am not sure about years, but I think that there are a large number of couples with newborns that are loosing some significant amount of sleep for at least 1 year or so. Not every day perhaps, but I think as new parents we run pretty much on sleep debt. I asked most of my friends and parents and this seems to be the case for all of them.

If my experience is not local and limited then someone has to do a study about loss of sleep and the effects this have on parents.

I found a lot of articles about the lack of sleep and the effect on mental health or health in general, but I am not finding a good explanation about how come if this is true people still become parents, then they go back to work and seems to function well. Is something special about parenting and recovery from lack of sleep? Or we all parents will remain forever with the negative effects due to sleep deprivation happening in early years of parenting?

Just sharing another personal experience: think book came out exactly in the year my kid was born. After reading some reviews and finding out that it does not give any advice about how to handle sleep deprivation I refuse to read it then as I was afraid it will make me more anxious about the small amount of sleep I was getting thus making me sleep even less :)

That might be the literal interpretation of what is said, but it's not how I interpreted it.

To me there is an implied "in the short term". So if I go without 4 hours of sleep today, I cannot just choose to sleep an extra 4 (or more) hours tomorrow. It's not an even trade. At some point more sleep has diminishing returns.

This does not mean more sleep has no value. Maybe it will add up over the next few days and we'll be back to good. People with sleep deprivation tend to have an REM rebound effect and personally when I've had a few poor nights in a row I will sleep noticeably deeper.

If someone is awake multiple days then sleep-like behaviour happens while they are still awake. They start to hallucinate or dream with eyes open, or enter microsleeps that they don't remember. It's not inconveivable to me (personal conjecture warning) that our diminished state is because some of our brain is doing the necessary upkeep normally relegated to sleep, so we're catching up while we are awake. It's just not something we notice until it gets really bad.

So, this would remove any permanent cognitive reduction, however you'll probably forever lose any memories that weren't correctly stored and so on.

In my opinion his claim was in regards to memory. If you lose sleep you can’t get that memory correctly “written” to your long term storage. And once you miss the timeframe when that memory was relevant you can’t recover it by simply sleeping more. So in effect, your short term memory suffers irrecoverable damage if you skip on sleep. Cognitive function does require adequate sleep and recovers to normal operation.

I have not read the book, but could the author simply mean that the recovery period for sleep deprivation is the same regardless if one try to make it up with more hours of sleeping than is regularly necessary?

Let say an individual is working 20 hours a day for 5 days, and in order for the brain and endocrine system to return to normal it takes 14 days of recovery. A few days of 12+ hours of sleep might not have any beneficial effect because the involved biological systems are too slow to get any benefit from the extra sleep, and the excessive amount of sleep might even cause additional problems which hinder recovery.

Making an educated guess, endocrine system is likely a big culprit here. Some hormones are specifically secreted during sleep, while the recipients of hormones are often triggered based on relative changes in hormone levels. If you have first a period of very low levels, followed by a period of sudden spikes, getting back to normal might take a while.

I think this is a really good guess.

Over the last 2 years I’ve had several periods of sleeping 0-2hrs/night for up to a week at a time (sick kid in the hospital).

One time, I was able to try to “catch up” in the following weeks by sleeping as much as I wanted. The other times, I was limited to my typical 7-8hrs.

No matter what, my recovery time was about 2 days of proper sleep for every day of sleep deprivation. Sleeping excessively (10+ hours) didn’t seem to accelerate recovery.

I can't be entirely sure what was meant but my sense from talking to people in this area is that statements like that are being made very literally. As in, if you do not sleep at all one night, its not like you can sleep an extra 8 hours the next day and be totally restored. The recovery process might involve a couple of days of sleeping an extra 3 hours, just for example.

I get the sense exercise and injury are good analogies. If you overexercise, cutting back by the amount you overdid it is too oversimplified; if you stop exercising for a month, you cant just expect to need or suffice with a month's worth later.

Why is permanent damage so hard to believe? If you listen to loud noises, you get permanent damage that you can't undo by staying quiet.

If you leave your hand on a hot stove too long, you can get permanent skin damage.

Firstly because I can observe an immediate improvement after catch up sleep. Im pretty sure the book doesn't say 'you get better but lose 0.1% each time' it says you can't make it up at all. If I had 4 hours sleep tonight I would feel horrible tomorrow, but even a 20min power nap would improve things.

But you wouldn’t be as well off as if you had just slept a good nights sleep to begin with.

It’s a highly nonlinear and even chaotic system - a living human being. The idea of “making it up” is a linear concept not entirely fit for the system. You can get back somewhat and you can’t undo everything.

I know from personal experience that however long you've stayed up, that 8 hours of sleep is the most you can do to help at that point, in other words after 20 hours of 'lost sleep' you can really only sleep for 8. (Edit: you can sleep for more but it will make no difference).

Or - if you lose a few hours every night during the week, you cannot 'catch up' on the weekend, it doesn't work like that.

A person who lives for years at 5 hours a weeknight but 11 on the weekends will be in poorer health than someone who just did 8 hours a night consistently.

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