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

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."'"

Comments

why is this new?

[Anonymous Coward]

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.

Re:why is this new?

[cvtan]

Blonde listening to tape saying, "Inhale. Exhale. Inhale. Exhale..."

Wrong headline

[Anonymous Coward]

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.

Re:Wrong headline

[Jstlook]

That isn't even what the article indicates. The article indicated that US Military tested a dolphin named Say for 15 days before a storm halted their experiment. The only other notable information in the article is that the dolphin achieved a 99% accuracy throughout the course of the experiments. That's better than your average (burger) flipper.

Re:Wrong headline

[Mikkeles]

Hell, that's better than your average software developer!

Re:Wrong headline

[PopeRatzo]

The news is that they can stay awake for 15 days at a time.

BFD. Hell, Rick James used to do that twice a month.

That's nothing

[matunos]

Republicans have been doing that for years.

*rimshot*

Re:That's nothing

[marcle]

Republicans, hell. I'm a hippie, and most of my brain is asleep most of the... What were we talking about?

Re:Evolution

[Anonymous Coward]

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.

Re:Evolution

[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

[JonySuede]

Memory consolidation , 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 !

I have to tell my wife about this.

[cvtan]

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.

[Black Parrot]

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.)

Re:So do birds.

[ledow]

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.

Re:Evolution

[Your.Master]

That doesn't explain why Dolphins didn't just turn sleep off, since they are warm and active throughout all time. Was it just so fundamental to the brain architecture that the segmenting was needed, or is sleep providing something else that dolphins still need?

Re:Evolution

[girlintraining]

That doesn't explain why Dolphins didn't just turn sleep off, since they are warm and active throughout all time. Was it just so fundamental to the brain architecture that the segmenting was needed, or is sleep providing something else that dolphins still need?

Bingo. The one question that everybody missed, because they were too busy making jokes or talking about Dolphins to realize that this evolutionary development can shed a lot of light on our own. Don't mod this up, no siree, we like our science dumbed down and sprinkled in apple sauce here! deeeerp. :(

Re:Evolution

[guttentag]

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% 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 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, and in return for this, you as an individual get to live longer than wild animals do.

One theory 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.

Re:Evolution

[girlintraining]

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.

Joke in there somewhere.

[fox171171]

I'm pretty sure there's a joke in there somewhere.

Only a half brain operating? I know people who...
...drive like that.
...talk like that.
...code like that.
...make decisions at Microsoft like that.
...decide to buy Apple products like that.

and so on...