Forgot your password?
typodupeerror
Science

Dolphins Can Sleep One-half of Their Brain At a Time Say Researchers 139

Posted by samzenpus
from the we-don't-need-no-stinking-sleep dept.
An anonymous reader writes "Looks like the evolution in multi-core computing is something nature has already figured out. Dolphins will sleep one core while the other remains vigilant, running background tasks necessary for survival. From the article: 'The scientists wrote: "From an anthropomorphic viewpoint, the ability of the dolphin to continuously monitor its environment for days without interruption seems extreme. However, the biological, sensory and cognitive ecology of these animals is relatively unique and demanding. If dolphins sleep like terrestrial animals, they might drown. If dolphins fail to maintain vigilance, they become susceptible to predation. As a result, the apparent 'extreme' capabilities these animals possess are likely to be quite normal, unspectacular, and necessary for survival from the dolphin's perspective."'"
This discussion has been archived. No new comments can be posted.

Dolphins Can Sleep One-half of Their Brain At a Time Say Researchers

Comments Filter:
  • why is this new? (Score:4, Insightful)

    by Anonymous Coward on Thursday October 18, 2012 @06:38PM (#41700101)

    This is known long ago... this is also an adaptation because dolphins breathing is not a reflex, so half the brain has to be always awake to remember breathing.

  • Wrong headline (Score:5, Informative)

    by Anonymous Coward on Thursday October 18, 2012 @06:43PM (#41700155)

    The news is that they can stay awake for 15 days at a time. Scientists have known for 30 years that dolphins can sleep with one hemisphere.

  • by matunos (1587263) on Thursday October 18, 2012 @06:44PM (#41700175)

    Republicans have been doing that for years.

    *rimshot*

  • A GM trait I'd be interested in acquiring.
    • by guttentag (313541)

      A GM trait I'd be interested in acquiring.

      For a moment there I thought you were talking about General Motors, and I was intrigued by the prospect that after decades of being half asleep at the wheel they might have produced something people are interested in acquiring. False alarm.

      • by siddesu (698447)
        I'd be interested in this too, I sleep at the wheel a lot, being able to have half the brain awake would be a boost to my driving potence.
  • by Cronock (1709244) on Thursday October 18, 2012 @06:44PM (#41700179)
    Hasn't this already been well known or quite some time?
  • Evolution (Score:2, Interesting)

    The real question is: Why is sleep needed in mammals in the first place? We've already found drugs that can keep a person going without sleep for weeks or months at a time, apparently without any significant reduction in cognitive ability or any significant change in neurological functioning. It's been investigated my the military for quite some time now.

    Evolution says the reason for sleep is that it improves a creature's ability to adapt... but what does sleep adapt us for? Why the downtime? Even here wit

    • Re:Evolution (Score:5, Informative)

      by Anonymous Coward on Thursday October 18, 2012 @07:10PM (#41700427)

      We've already found drugs that can keep a person going without sleep for weeks or months at a time, apparently without any significant reduction in cognitive ability or any significant change in neurological functioning.

      Link please, otherwise I'm calling bogus. The official world record for going without sleep is 18 days.

      Look up 'Fatal Familial Insomnia' in which death follows (as best as anyone can tell) from lack of sleep.

      • by ceoyoyo (59147)

        And that 18 days was in a rocking chair competition, not exactly a cognitively demanding task, and one with lots of opportunities for microsleeps.

    • Re: (Score:3, Informative)

      by Anonymous Coward

      Those drugs can keep you alert for extended periods, but then you need an inordinate amount of recovery time for the missed sleep and performance never seems as good as normal. The increased uptime, as it were, isn't free. Yes, I've studied some brain chemistry with regards to drugs such as modafinil.

    • Re:Evolution (Score:5, Interesting)

      by JonySuede (1908576) on Thursday October 18, 2012 @07:21PM (#41700531) Journal
      Memory consolidation [wikipedia.org] , occurs more efficiently during sleep. That alone is worth it's evolutionary cost of sleep. Sure, Nature could have stumbled upon a memory consolidation scheme that do not involved sleep but it did not and evolutionary wise it seems that having a solid long term memory is more beneficial than not having to sleep. BTW if the drugs you talk about are orexin activator/recapture inhibitor/supressing enzyme inhibitor, only one: Orextin-A, is currently without know side effects. If those drugs you talked about do not act on the orexin transmitter up regulation, please tell me about them !
      • by Anonymous Coward

        Related to that, while we sleep we apparently learn by essentially reliving those memories thousands of times. One of the best things you can do after learning something new is take a good nap.

        People tend to think of sleep as a point that the brain is "turned off" but that's not accurate at all. It is an alternate method of functioning, and vital to how we operate. I saw this as someone who has a lot of trouble sleeping and I know first hand what a long term lack of sleep can do to a person. I sleep so ligh

      • So dreaming is those night-time batch jobs that reorganise your database indexes, defrag your files, clear out soft deletes and all that shit?

        I always felt a bit like a mainframe.

        • Never thought about that in that way before and I am not qualified enough to confirm it but my guts tell me that : this analogy is unfit for Slashdot as it is probably a good one.
    • We've already found drugs that can keep a person going without sleep for weeks or months at a time, apparently without any significant reduction in cognitive ability or any significant change in neurological functioning.

      What drugs are those, exactly?

    • Re:Evolution (Score:5, Interesting)

      by guttentag (313541) on Thursday October 18, 2012 @08:55PM (#41701101) Journal

      Evolution says the reason for sleep is that it improves a creature's ability to adapt... but what does sleep adapt us for?

      Most creatures don't live long enough to have a need to adapt as an individual, but they adapt as a species over generations.

      Humans probably have the greatest need to adapt as individuals. Every day:

      • laws are changing. Today: Gay Marriage Legal! Tomorrow: Gay Marriage Illegal and Unconstitutional because the 40.46% [wikipedia.org] of the electorate said so! Next Friday: Bingo at the Supreme Court!)
      • religions are changing. Today: Earth is the Center of the Universe and Stoning Pregnant Women for Sex Out of Wedlock is Good! Tomorrow: Earth Not the Center of the Universe and Abortion is Evil. Next Friday: Earth is the center of the Universe every third Thursday during certain seasons, check local listings or pastors for details.
      • food sources and taboos are changing. Today: steel cans lined with BPA keep your family's food fresh! Tomorrow: BPA in bottles bad, but we're OK with BPA in cans! Next Friday: FDA outlaws all estrogen-mimicking substances including Richard Simmons.
      • business and personal relationships are changing. Today: Great work, Invaluable Employee/Loving Wife! Tomorrow: You've been replaced by someone cheaper/someone cheaper! Next Friday: Special Rates at the Chapel of Love for Couples Marrying Each Other for the 3rd Time!
      • even the side of the street [wikipedia.org] you may park on is changing on a regular basis.

      You have to be able to adapt because society ensures that someone is constantly moving your cheese [wikipedia.org], and in return for this, you as an individual get to live longer than wild animals do.

      One theory [wikipedia.org] about why we need to sleep is that we need to filter out all the crap from the stuff we need to save. During REM sleep the neurons are subjected to spontaneous, chaotic activity, strengthening memories whose neuronal substrate is already sufficiently established, and disintegrating those that are weaker. Ever built a sandcastle by the water line at the beach? The walls that are not tightly packed get washed away when the water hits them, but the ones that are tightly packed survive and seem to actually be strengthened by the encounter. In a way, that's what REM sleep may do for our memories. Without that, it's all just an unstable jumble, and you can't adapt to all the crap in your life without the clarity to know what day it is or where the heck you're supposed to be.

      • by girlintraining (1395911) on Thursday October 18, 2012 @09:02PM (#41701145)

        I don't know what gay marriage, the FDA, mail-order girlfriends, and violations of space-time causality, and sandcastles by the beach have to do with the importance of sleep... but I can say with a fair degree of certainty that having read your post, you are a case study in what happens when someone doesn't get any. Please man, go to bed. The internet, such as it is, will not want for a missed opportunity for you to post to slashdot.

      • by gentryx (759438) *
        Epic post!
    • Yeah those drugs work great until suddenly everyone around you is a cop, and you can't get the ants out from under your skin.

    • by lennier (44736)

      We've already found drugs that can keep a person going without sleep for weeks or months at a time, apparently without any significant reduction in cognitive ability or any significant change in neurological functioning. It's been investigated my the military for quite some time now.

      Moving on, in completely unrelated news, there's also been a huge spike in mental health problems in currently deployed US soldiers. Officials say this is perfectly normal and nothing to be concerned about. Now for a word from our sponsor. Sleep-No-Mor(Tm), one capsule a day and those eight wasted night hours are yours again!

    • We sleep because there is a Day and Night. Sun = More Energy & More Visibility. It leads to cycles of activity, which leads to traits which take advantage of these cycles. It's not a mystery. Activity and Rest cycles exist because that's how cells work at the chemical level... It would be like saying: "Daisies and many plants close up after the sun goes down, but WHY!?! It's a mystery!" Protip: Plants don't think; There is no reasoning with plants.
    • I've asked myself the same question, and one night the answer came to me in a dream.

      Too bad I forgot the dream so now I still don't know.

    • In terms of evolution I could see the initial advantage of sleep, is a period of time of reduced activity to allow us to conserve energy better. You stay awake every day you will need an additional food and water to keep going, in scarce areas animals who slept got an advantage of needing less food, compensating for the extra energy it takes to keep them warm blooded.

      The next advantage is the fact to sleep we often need to be in a safe area. So we build or find safe areas to keep predators at bay. So the a

    • by mcgrew (92797) *

      The real question is: Why is sleep needed in mammals in the first place?

      I've always wondered that myself, and not just in mammals. Sleep seems to be counter-evolutionary; when you're asleep, you're helpless.

      We've already found drugs that can keep a person going without sleep for weeks or months at a time, apparently without any significant reduction in cognitive ability or any significant change in neurological functioning.

      That is incorrect, as I saw firsthand in 1974 when I was stationed in Thailand in the

      • in 1974 when I was stationed in Thailand in the USAF. [...] I was eating amphetamines like crazy. [...] Then one morning I woke up in a strange bed with a strange woman wondering where the hell I was; the entire previous week was completely gone from my memory

        On a scale of 1 (store clerk) via 7 (engine mechanic) to 10 (jet pilot) I presume you were somewhere near zero (dishwasher), or you wouldn't be here.

  • We are indeed inferior to dolphins, brain-wise. Makes you wonder what the mice can pull off!
    • We are indeed inferior to dolphins, brain-wise. Makes you wonder what the mice can pull off!

      Depends on whether you're talking about Pinky or The Brain.

    • by mattack2 (1165421)

      They already created the Earth, what else do you want?

      (http://en.wikipedia.org/wiki/Minor_characters_from_The_Hitchhiker%27s_Guide_to_the_Galaxy#Frankie_and_Benjy_Mouse)

    • by AdamWill (604569)

      And so was Iain M. Banks, who had a minor character in Consider Phlebas who'd got gene-modified to do this (he had both halves of his brain awake for 8 hours, then left half for 8 hours, then right half for 8 hours). Wonder if he'd heard about this dolphin thing at the time (others say this isn't really news...)

  • As a former dolphin researcher at the Kewalo Basin Marine Mammal Laboratory of the University of Hawaii I can say that we've known about split brain sleeping for at least three decades. I had always wanted to run an experiment looking for an acoustic equivalent to Rapid Eye Movement in dolphins. It could still be called REM sleep just substituting Eye with Echolocation. Since you really don't want to attach EKG leads to a swimming dolphin we'd have needed a set of directional hydrophones arrayed around t
    • by HJED (1304957)
      Surley if dolphins had REM it would still invole their eyes, rapid echolocation would be a huge evolutionary disadvantage as predators could detect it and it would disrupt their navigation if they where doing the half awake thing?
  • Does that mean that a body doesn't need sleep - only the brain? Or have their bodies adapted in some special way that ours hasn't?
    • Your body might suffer from your brain not sleeping, for instance when you drive into a wall, but there is nothing in particular the body needs sleep (different than rest) for. From the perspective of your body, you sleeping is just a reduction in the amount of talking your brain does. That said, the body can handle lots of things the brain can't. Some desert mammals (goats, in particular) can let their body heat up way past what would be fatal for their brains, while using some nifty plumbing to keep
    • Does that mean that a body doesn't need sleep - only the brain? Or have their bodies adapted in some special way that ours hasn't?

      I'm 49 and I have stayed up for 36 hours straight, at work (system programmer/admin), several times this year alone. Even after 10 hours of sleep I feel like crap the next day with headache and lethargy, like I'm dehydrated or *really* hung over (though I'm neither). My body has otherwise felt fine.

      I thought I read/heard/saw (like on Discovery Channel) that the brain uses chemistry during waking periods that can only be replenished during sleep periods. If so, this would explain a lot, especially peopl

  • This is also how Steve Ballmer gives keynotes

  • http://www.radiolab.org/2007/may/24/one-eye-open/ [radiolab.org]

    porpoises mentioned 7:30 but it's all fascinating

  • Big deal.

    I perfectly of that.

    am capable doing too .

  • Most people don't know that they're half asleep, but they are. All the time. At least the dolphins seem to turn both cores on every now and then.

    Perhaps we could have the dolphins vote on our behalf next month. And if they elect a dolphin, it might not be such a bad thing, so long as their choice is 35 or older and born within U.S. territorial waters. We won't care what color dolphin they choose. Think of all the money we'd save collectively by not donating to campaigns that are just going to scream garb
  • by cvtan (752695) on Thursday October 18, 2012 @07:25PM (#41700551)
    Now when she asks why I don't listen to her, I can just explain that the half of my brain running the audio is shut down to conserve energy.
  • So do birds. (Score:5, Interesting)

    by Black Parrot (19622) on Thursday October 18, 2012 @07:36PM (#41700615)

    This is old "news". (Can we call it "olds"?)

    Supposedly when you see a row of birds standing on a cable, all the ones in the middle are asleep, and the two on the end have half a brain awake so that their outside eye is paying attention.

    More recent result is that even in humans, 'asleep' isn't a boolean proposition. Different parts of your brain may go to sleep at different times. Sometimes leads to "normal" sleepwalking, sometimes to horrid behavior because the impluse-suppression part is asleep and most of the rest isn't. See the overview article in a recent issue of Scientific American. (Current or previous issue, IIRC.)

    • +1 for "olds"
    • Re:So do birds. (Score:4, Insightful)

      by ledow (319597) on Friday October 19, 2012 @03:43AM (#41702903) Homepage

      And anyone who thinks that the brain is inherently capable of only doing one thing has never driven long-distance.

      Has *anybody* never had that experience where you are driving along thinking and then suddenly realise you've just navigated the past 20 miles, through traffic, round corners, through junctions, with gear-changes, etc. without remembering doing so?

      Your brain is more than capable of doing those tasks - and alerting you to problems just as quickly as when you're concentrating on the task - in the background without you knowing. (What scares me most about them is not the fact that it happens, but that I assume I stopped at red lights, followed traffic signs, didn't ram someone off the road, etc. and have to quickly recall events that I seem to have taken no conscious part in!)

      I've also had the (strange) privilege of knowing someone with multiple-personality-syndrome. This is extremely similar - one personality is at the fore but the others are there, in the background, observing events and doing things, just out of mind at that moment. In fact, in MPS, it's just a more pronounced version triggered by certain psychological problems (lots of abuse cases, lots of a very particular type of psychiatric therapy that seems to "trigger" MPS in vulnerable individuals - and is STILL practised in the one part of America where most MPS cases come from!).

      Your brain is not a single thing. It's a collection of billions of things, each with their own job. They group and work together but they also can separate off (otherwise you would have to "think" about how to move your arm rather than just passing it off to a group of brain cells that do that all day long) and even divide your consciousness in two in perfectly ordinary people with no mental health issues.

      And, like others have said, have you never had that thing late at night where you wake up because of an odd (and quiet) sound despite the fact that every other night you slept like a baby. How do you think that works? The brain is always awake, in some fashion, it's just a matter of whether it decides something is a threat or not (otherwise every predator would just wait until your were asleep because you'd be an easy target), and then "presses the emergency button" to get the rest operational very quickly.

      The dolphin thing is well-known. And any idiot with a cat knows that it doesn't really "sleep" for 18 hours a day, it's always aware and very, very rarely in an actual complete sleep (for the first time in 12 years, I manage to "scare" my cat the other day because it was completely, 100% asleep and didn't hear me come in, didn't feel me approach, until I stroked its fur - I actually thought it was dead, it was so deep in sleep).

      And every driver will tell you that they have driven on a kind of "automatic pilot" including some of the most complex observation, judgement, quick-reaction and motor skills that the average person will perform in a day, while they were thinking about what to have for dinner.

      Humans are animals. Animals have brains. Brains are a collection of groups of cells that, by their very nature, are inherently malleable, ever-changing and independent. It's no shock that dolphins can do this. What's more interesting is that humans seem to have lost the ability/need to do this so much.

      • by ArsonSmith (13997)

        Every time I drive home from the bar I wake up the next morning with this feeling.

      • Has *anybody* never had that experience where you are driving along thinking and then suddenly realise you've just navigated the past 20 miles, through traffic, round corners, through junctions, with gear-changes, etc. without remembering doing so?

        I have even felt this happen when I commute to work. I have crossed two streets, taken the train, walked into work, while the last I can really remember is leaving home (or something I did before leaving home). I have had this happen often enough that I joke that I can commute blindfolded to work.

  • That's nothing... There are plenty of people on the NY Thruway who can do this and drive at the same time!

  • Just a matter of time before we have dolphin-centric questions on the SATs. And of course, the schools will be teaching echolocation to the test...
  • And this explains how they have so much time to be jerks; although I could be thinking of porpoises.

    • by xlsior (524145)
      Does make you wonder -- if half their brain shuts down at alternate times, does that also mean that their personality changes for those periods?
    • by kid_wonder (21480)

      could not agree with you more. as much as i respect their intelligence [discovery.com] and creativity [world-science.net] and all that ...

      but they are still the worst [aardvarknyc.com] monsters [slate.com] on the planet ... ok, well besides us.

      and just because i can't find an article about dolphins raping humans does not mean that it doesn't happen. you have been warned

  • "Sleep" really doesn't work like that as a verb.
  • Dolphins Can Sleep One-half of Their Brain At a Time Say Researchers

    Why would an intelligent species like dolphins have invented meetings?

  • http://www.theonion.com/articles/dolphins-evolve-opposable-thumbs,284/ [theonion.com] "'I believe I speak for the entire human race when I say, 'Holy fuck,'' said Oceanographic Institute director Dr. James Aoki"
  • This is old news. It was discovered long ago. Not only that but they found this about ducks before that. Even some humans do this, more among males perhaps due to greater division of functions due to later maturation and greater corpus callosum separation.

    News that matters? Maybe.
    News that is timely? Not so.

  • Giraffes have long necks, and diney-sowers is all dead!

God may be subtle, but he isn't plain mean. -- Albert Einstein

Working...