4 ms·

Is it possible for a human(for example a meditator) to learn to sleep with one eye open ?

by petra 10y ago

Mz 10y ago
Yes. My son used to sleep with one eye open. After serving in Vietnam, my father habitually napped with both eyes open.
- mi100hael 10y ago
  A human can sleep with one or both eyes open, but as far as I know it's not at all related to brain activity. The person's brain is still fully asleep. See: https://en.wikipedia.org/wiki/Lagophthalmos#Nocturnal https://en.wikipedia.org/wiki/Lagophthalmos#Nocturnal
  - sp332 10y ago
    Your brain can still react to things when it's asleep though. You can be shaken awake, or shouted awake, or woken up by a bright light. It doesn't seem impossible that seeing something dangerous while asleep could wake you up.
    - Mz 10y ago
      Presumably this is exactly why my father learned to sleep with his eyes open while caught behind enemy lines in Vietnam for, as I understand it, a month or more.
  - david-given 10y ago
    I remember once waking up, when, for some reason, I had my eyes open. It was weird: all I saw was just shape; not shapes of anything in particular, but just pure essence of what shape really was. Then, over a period of a few seconds, and in distinct chunks, it suddenly resolved into things I could actually identify, and I realise what I was looking at. After the fact I put this down as the pattern-matching areas of my brain starting working rather more slowly than the rest of my visual cortex, so it took a while before they starting resolving what my eyes were seeing into meaningful concepts. I have a variety of mild sleep disorders. I can recommend them as a hobby; they're fascinating. Admittedly, it helps that being hag-ridden is so familiar it's practically an old friend; the first few times were utterly terrifying[ * ]. But the weirdest of the lot is something I've dubbed false memory syndrome, where I'll remember something, while quite conscious, which never happened, and frequently in quite some detail. Just last night I had apparently written and drawn a comic book. That was better than the time I was on the run after having killed someone... [ * ] Apparently there's a theory that this is where alien abduction myths come from.
    - trentmb 10y ago
      > It was weird: all I saw was just shape; not shapes of anything in particular, but just pure essence of what shape really was. Wonder if that's what it's like for a newborn. https://en.wikipedia.org/wiki/Molyneux%27s_problem https://en.wikipedia.org/wiki/Molyneux%27s_problem
      - pbhjpbhj 10y ago
        There is some conjecture that babies have synesthesia too - so it would be a case of visually receiving sense shape imagery and the brain interpreting that as colours, forms, tastes, pressure, warmth, scents, and such too. Now that seems like enough to make you scream and seek solace in innate behaviours.
    - animal531 10y ago
      Yeah, that first part happens when you on occasion mentally wake up faster than your body does, which is then still sleep paralysed. It can be pretty scary the first time, as it feels as if there are shapes (ie. humanoids) lurking around you. Also when you try to move your brain remembers and plays the motion as if it's happening, but you're still paralysed so you keep resetting back to whatever position you're lying it. The same probably holds true for sight.
- Someone 10y ago
  That seems to imply that the unconscious part of the brain still can use visual input while the 'mind' is sleeping (just like it can 'read' the output of your ears, so that it can wake you when your alarm clock rings) Does anybody know whether that is true? Similarly, does the knee reflex work when humans are sleeping? Edit: on the knee reflex, there's http://ajplegacy.physiology.org/content/68/2/345 http://ajplegacy.physiology.org/content/68/2/345. Paywalled, but the knee reflex seems diminished/absent during sleep. Edit 2: quite surprising, as the knee reflex is so fast that a nerve signal cannot travel to the brain and back within its response time (and of course, there's the spinal cat, that walks on a treadmill after its brain has been disconnected from its spinal cord (https://en.wikipedia.org/wiki/Spinal_locomotion) https://en.wikipedia.org/wiki/Spinal_locomotion))
  - drdeca 10y ago
    I don't know, but I would suspect that doing the knee reflex thing with someone asleep would often cause them to wake up? But, also, I think I heard that the signal doesn't get all the way up to the brain before the signal to kick or whatever starts going down? (I am unsure of this though.) So, I would think that the brain being like it is when the person is asleep wouldn't stop the kick reflex thing, because the brain isn't even what causes the kick reflex thing? So my guess is that they would kick and then likely wake up. I'm not certain of this though. Please correct me if I am wrong.
    - sp332 10y ago
      Yes, the reflex is controlled by the "dorsal root" ganglion, at the spine.
      - duaneb 10y ago
        Perhaps sleep is a full body affair.
  - SapphireSun 10y ago
    Bright lights wake you up right? I'm not sure how complex a stimulus you can interpret while asleep, but it wouldn't surprise me. After all your brain doesn't turn off, it's just in a different mode of operation. EDIT: To be fair, I wouldn't be surprised either if there was a dedicated circuit that sensed change in luminous energy that bypassed V1. I'd google but I'm on limited wireless right now. Here's an article that's informative, but doesn't quite answer the question: http://phenomena.nationalgeographic.com/2014/03/13/how-light-wakes-up-the-brain/ http://phenomena.nationalgeographic.com/2014/03/13/how-light... It talks about the blue light pathway that David Berson discovered in intrinsically photosensitive ganglion cells. This was surprising because, while this was before my time, I think most people thought that it was the rods and cones that were photosensitive, containing proteins called opsins that transduce light into neural signal. Rods and cones can be considered input cells, ganglion cells sit above the retinal circuitry can can be through of as output cells that perform computations from their inputs and pipe that information down the optic nerve, which eventually leads to primary visual cortex located at the back of your skull. Though there are plenty of opportunities for side branching minor paths.
ljlolel 10y ago
Can split brain patients do that? https://en.wikipedia.org/wiki/Split-brain https://en.wikipedia.org/wiki/Split-brain

Is it possible for a human(for example a meditator) to learn to sleep with one eye open ?

by petra 10y ago

Is it possible for a human(for example a meditator) to learn to sleep with one eye open ?

Mz 10y ago

Yes. My son used to sleep with one eye open. After serving in Vietnam, my father habitually napped with both eyes open.

mi100hael 10y ago
A human can sleep with one or both eyes open, but as far as I know it's not at all related to brain activity. The person's brain is still fully asleep. See: https://en.wikipedia.org/wiki/Lagophthalmos#Nocturnal https://en.wikipedia.org/wiki/Lagophthalmos#Nocturnal
- sp332 10y ago
  Your brain can still react to things when it's asleep though. You can be shaken awake, or shouted awake, or woken up by a bright light. It doesn't seem impossible that seeing something dangerous while asleep could wake you up.
  - Mz 10y ago
    Presumably this is exactly why my father learned to sleep with his eyes open while caught behind enemy lines in Vietnam for, as I understand it, a month or more.
- david-given 10y ago
  I remember once waking up, when, for some reason, I had my eyes open. It was weird: all I saw was just shape; not shapes of anything in particular, but just pure essence of what shape really was. Then, over a period of a few seconds, and in distinct chunks, it suddenly resolved into things I could actually identify, and I realise what I was looking at. After the fact I put this down as the pattern-matching areas of my brain starting working rather more slowly than the rest of my visual cortex, so it took a while before they starting resolving what my eyes were seeing into meaningful concepts. I have a variety of mild sleep disorders. I can recommend them as a hobby; they're fascinating. Admittedly, it helps that being hag-ridden is so familiar it's practically an old friend; the first few times were utterly terrifying[ * ]. But the weirdest of the lot is something I've dubbed false memory syndrome, where I'll remember something, while quite conscious, which never happened, and frequently in quite some detail. Just last night I had apparently written and drawn a comic book. That was better than the time I was on the run after having killed someone... [ * ] Apparently there's a theory that this is where alien abduction myths come from.
  - trentmb 10y ago
    > It was weird: all I saw was just shape; not shapes of anything in particular, but just pure essence of what shape really was. Wonder if that's what it's like for a newborn. https://en.wikipedia.org/wiki/Molyneux%27s_problem https://en.wikipedia.org/wiki/Molyneux%27s_problem
    - pbhjpbhj 10y ago
      There is some conjecture that babies have synesthesia too - so it would be a case of visually receiving sense shape imagery and the brain interpreting that as colours, forms, tastes, pressure, warmth, scents, and such too. Now that seems like enough to make you scream and seek solace in innate behaviours.
  - animal531 10y ago
    Yeah, that first part happens when you on occasion mentally wake up faster than your body does, which is then still sleep paralysed. It can be pretty scary the first time, as it feels as if there are shapes (ie. humanoids) lurking around you. Also when you try to move your brain remembers and plays the motion as if it's happening, but you're still paralysed so you keep resetting back to whatever position you're lying it. The same probably holds true for sight.
Someone 10y ago
That seems to imply that the unconscious part of the brain still can use visual input while the 'mind' is sleeping (just like it can 'read' the output of your ears, so that it can wake you when your alarm clock rings) Does anybody know whether that is true? Similarly, does the knee reflex work when humans are sleeping? Edit: on the knee reflex, there's http://ajplegacy.physiology.org/content/68/2/345 http://ajplegacy.physiology.org/content/68/2/345. Paywalled, but the knee reflex seems diminished/absent during sleep. Edit 2: quite surprising, as the knee reflex is so fast that a nerve signal cannot travel to the brain and back within its response time (and of course, there's the spinal cat, that walks on a treadmill after its brain has been disconnected from its spinal cord (https://en.wikipedia.org/wiki/Spinal_locomotion) https://en.wikipedia.org/wiki/Spinal_locomotion))
- drdeca 10y ago
  I don't know, but I would suspect that doing the knee reflex thing with someone asleep would often cause them to wake up? But, also, I think I heard that the signal doesn't get all the way up to the brain before the signal to kick or whatever starts going down? (I am unsure of this though.) So, I would think that the brain being like it is when the person is asleep wouldn't stop the kick reflex thing, because the brain isn't even what causes the kick reflex thing? So my guess is that they would kick and then likely wake up. I'm not certain of this though. Please correct me if I am wrong.
  - sp332 10y ago
    Yes, the reflex is controlled by the "dorsal root" ganglion, at the spine.
    - duaneb 10y ago
      Perhaps sleep is a full body affair.
- SapphireSun 10y ago
  Bright lights wake you up right? I'm not sure how complex a stimulus you can interpret while asleep, but it wouldn't surprise me. After all your brain doesn't turn off, it's just in a different mode of operation. EDIT: To be fair, I wouldn't be surprised either if there was a dedicated circuit that sensed change in luminous energy that bypassed V1. I'd google but I'm on limited wireless right now. Here's an article that's informative, but doesn't quite answer the question: http://phenomena.nationalgeographic.com/2014/03/13/how-light-wakes-up-the-brain/ http://phenomena.nationalgeographic.com/2014/03/13/how-light... It talks about the blue light pathway that David Berson discovered in intrinsically photosensitive ganglion cells. This was surprising because, while this was before my time, I think most people thought that it was the rods and cones that were photosensitive, containing proteins called opsins that transduce light into neural signal. Rods and cones can be considered input cells, ganglion cells sit above the retinal circuitry can can be through of as output cells that perform computations from their inputs and pipe that information down the optic nerve, which eventually leads to primary visual cortex located at the back of your skull. Though there are plenty of opportunities for side branching minor paths.

ljlolel 10y ago

Can split brain patients do that? https://en.wikipedia.org/wiki/Split-brain https://en.wikipedia.org/wiki/Split-brain