4 ms·

Interesting, but the article actually says hardly anything about sleep, and "generalists" here means "organisms with the ability to change in response to their

by gjm11 16y ago

Interesting, but the article actually says hardly anything about sleep, and "generalists" here means "organisms with the ability to change in response to their environment". There's not the slightest suggestion that human beings who are more "generalist" need more sleep than ones who are "specialist" in any normal sense. Incidentally, sloths and armadillos sleep for about 20 hours a day. Are they generalists?

city41 16y ago
My cat must be the king of generality.
DougBTX 16y ago
Thanks. I found the article much more interesting than the title suggested.
scott_s 16y ago
If A -> B, it's not necessarily true that B -> A. (A = generalist, B = sleeps a lot.)
- gjm11 16y ago
  On the other hand, if B is "sleeps more" (which was, after all, the claim in the subject line here) then A -> B and B -> A are pretty much the same thing, except that the meaning of B -> A is a little unclear.
  - scott_s 16y ago
    Not at all. There may be many things that can cause B ("sleeps more"), such as "hunts big game." So A -> B does not imply B -> A.
    - gjm11 16y ago
      Sorry, I wasn't clear. The point is that here B is "is a generalist rather than a specialist" and A is "sleeps more than a specialist". If the claim is "generalists sleep more than specialists" then any instance where a specialist sleeps more is a refutation of the claim if it's made in a very strong form (all generalists sleep more than all specialists) and evidence against the claim if it's made in a weaker form (generalists tend to sleep more than specialists). (It might in some cases be only very weak evidence. Indeed, I think it is only weak evidence here; armadillos and sloths are just two particular cases. So far as I know, though, there's no particular tendency for more-generalist animals to sleep longer.)
      - dbingham 16y ago
        I think the article was talking specifically about humans, and not other species. In that case, there's a baseline of sleep required for a human. Need more than that? You're a generalist. Need less? You're a specialist. When you go bringing in other species you have to change the baseline. Sloths and armadillos sleep as much as they do for other reasons than being worn out from brain plasticity.
        gjm11 16y ago
        > I think the article was talking specifically about humans, and not other species. Um. Looks to me as if it's almost all about _neural plasticity_, which is not at all the same thing as being a generalist human rather than a specialist one. And the only thing I can find in it that says anything about one set of humans versus another is a comment about autism. (Whether there's evidence that autistic people have less neural plasticity, I don't know.) And while I've only skimmed the paper they point to when saying that "one hypothesis holds that sleep is the price we have to pay for plasticity the previous day", I don't see anything in it that says anything about specialist versus generalist humans, or indeed about any group of humans versus any other.
dbingham 16y ago
It says it right here: "Synaptic pruning and other mechanisms for synaptic plasticity allow for learning and memory, but they are energetically costly. Indeed, one hypothesis holds that sleep is the price we have to pay for plasticity the previous day. (see here)" "Synaptic pruning and other mechanisms for synaptic plasticity" -- Being a generalist. "...they are energetically costly. Indeed, one hypothesis holds that sleep is the price we have to pay for plasticity the previous day." -- Requires more sleep. Here's the wikipedia article on Neuroplasticity: http://en.wikipedia.org/wiki/Neuroplasticity http://en.wikipedia.org/wiki/Neuroplasticity It is the process of changing your brain. When neurons fire together they wire together, forming a neural pathway. When they fire apart, they wire apart. So if you're doing one thing - programming requiring high amounts of logic, for instance - a certain bunch of neurons fire together. They start forming a pathway. If you then go do something else in the same day, requiring a different bunch of neurons to fire, say play an instrument or write a fiction story, you'll start forming a different neural pathway. If some of the neurons overlap, but not all, you might end up beginning to break down the pathway you were building earlier in the day. All of these activities require more energy than simply continuing to use the same series of pathways you built earlier in the day.

by gjm11 16y ago

city41 16y ago

My cat must be the king of generality.

DougBTX 16y ago

Thanks. I found the article much more interesting than the title suggested.

scott_s 16y ago

If A -> B, it's not necessarily true that B -> A. (A = generalist, B = sleeps a lot.)

gjm11 16y ago
On the other hand, if B is "sleeps more" (which was, after all, the claim in the subject line here) then A -> B and B -> A are pretty much the same thing, except that the meaning of B -> A is a little unclear.
- scott_s 16y ago
  Not at all. There may be many things that can cause B ("sleeps more"), such as "hunts big game." So A -> B does not imply B -> A.
  - gjm11 16y ago
    Sorry, I wasn't clear. The point is that here B is "is a generalist rather than a specialist" and A is "sleeps more than a specialist". If the claim is "generalists sleep more than specialists" then any instance where a specialist sleeps more is a refutation of the claim if it's made in a very strong form (all generalists sleep more than all specialists) and evidence against the claim if it's made in a weaker form (generalists tend to sleep more than specialists). (It might in some cases be only very weak evidence. Indeed, I think it is only weak evidence here; armadillos and sloths are just two particular cases. So far as I know, though, there's no particular tendency for more-generalist animals to sleep longer.)
    - dbingham 16y ago
      I think the article was talking specifically about humans, and not other species. In that case, there's a baseline of sleep required for a human. Need more than that? You're a generalist. Need less? You're a specialist. When you go bringing in other species you have to change the baseline. Sloths and armadillos sleep as much as they do for other reasons than being worn out from brain plasticity.
      - gjm11 16y ago
        > I think the article was talking specifically about humans, and not other species. Um. Looks to me as if it's almost all about _neural plasticity_, which is not at all the same thing as being a generalist human rather than a specialist one. And the only thing I can find in it that says anything about one set of humans versus another is a comment about autism. (Whether there's evidence that autistic people have less neural plasticity, I don't know.) And while I've only skimmed the paper they point to when saying that "one hypothesis holds that sleep is the price we have to pay for plasticity the previous day", I don't see anything in it that says anything about specialist versus generalist humans, or indeed about any group of humans versus any other.

dbingham 16y ago

It says it right here: "Synaptic pruning and other mechanisms for synaptic plasticity allow for learning and memory, but they are energetically costly. Indeed, one hypothesis holds that sleep is the price we have to pay for plasticity the previous day. (see here)" "Synaptic pruning and other mechanisms for synaptic plasticity" -- Being a generalist. "...they are energetically costly. Indeed, one hypothesis holds that sleep is the price we have to pay for plasticity the previous day." -- Requires more sleep. Here's the wikipedia article on Neuroplasticity: http://en.wikipedia.org/wiki/Neuroplasticity http://en.wikipedia.org/wiki/Neuroplasticity It is the process of changing your brain. When neurons fire together they wire together, forming a neural pathway. When they fire apart, they wire apart. So if you're doing one thing - programming requiring high amounts of logic, for instance - a certain bunch of neurons fire together. They start forming a pathway. If you then go do something else in the same day, requiring a different bunch of neurons to fire, say play an instrument or write a fiction story, you'll start forming a different neural pathway. If some of the neurons overlap, but not all, you might end up beginning to break down the pathway you were building earlier in the day. All of these activities require more energy than simply continuing to use the same series of pathways you built earlier in the day.