8 ms·

So, I still don't know if you are irreversibly dead if your brain stops all activity. I.e. is the state of your brain preserved just by the connections of the

by Tepix 7y ago

So, I still don't know if you are irreversibly dead if your brain stops all activity. I.e. is the state of your brain preserved just by the connections of the neurons? Or is the "RAM" also critical?

adrianN 7y ago
Electrocuting the brain like in electroshock therapy most likely wipes any electrical activity. That seems to indicate that the brain is able to recover after such an event.
mkesper 7y ago
When your brain doesn't get oxygen it will die. See https://en.wikipedia.org/wiki/Cerebral_hypoxia https://en.wikipedia.org/wiki/Cerebral_hypoxia
- unnouinceput 7y ago
  It's more then that in this case. She had not vital signs at all, heart not beating and providing oxygen included.
  - pc86 7y ago
    The brain was provided oxygen, just not by her heart.
    - meowface 7y ago
      Also, perhaps during such a cold state more cells are able to stay alive despite having less oxygen to work with? Maybe due to a reduction in how much energy they use or need per unit time? Just speculating.
      - heavyset_go 7y ago
        Cell death is a metabolic process and it can be arrested if overall metabolism is arrested, as well.
  - Teandw 7y ago
    It's important to note that she had no 'detectable' vital signs. Not that she didn't have any vital signs. Very important difference.
ad404b8a372f2b9 7y ago
What leads to brain damage, as I understand it, is lack of oxygen like all other organs and hypothermia reduces your brain activity and its consumption of oxygen but I always interpreted brain activity as an indicator of oxygen consumption and not as something that'd have a cause-effect relationship with brain damage.
vo2maxer 7y ago
Here is an interesting review of the definitions of death: https://academic.oup.com/jlb/article/3/3/743/2327864 https://academic.oup.com/jlb/article/3/3/743/2327864
me_me_me 7y ago
>Or is the "RAM" also critical? There are cases of people without short term memory. That to me qualifies as RAM, guess its not critical to survival.
- missosoup 7y ago
  Short term memory is more akin to cache. The connections between the neurons is the architecture. The neurons themselves have state. If that state is wiped across the brain, I'd be surprised if the body connected to it could even still keep itself alive. To the actual question though, neurons die/fail very quickly at their normal metabolic rate without an oxygen supply. You are certainly dead once that happens. These procedures are all about providing some oxygen and dropping the metabolic rate to keep the neurons alive longer than they would unassisted.
OscarCunningham 7y ago
Lightning strikes don't wipe people's personalities. Also during epileptic seizures people's neurons fire in abnormal ways, but then return to normal afterwards. So I'd say that the RAM isn't critical; humans can boot from disk.
- navaati 7y ago
  > humans can boot from disk Now I want to read a sci-fi book with this sentence in it.
  - TheSpiceIsLife 7y ago
    Alter Carbon: A key concept in Netflix's cyberpunk series Altered Carbon is the 'stack', an advanced hard drive installed on the brainstem on which a person can save a copy of their consciousness. The main effect of stack technology is a form of immortality, because a stack can be installed into another body if the original body dies. But there’s another a major implication only hinted at during the first season of Altered Carbon: If you could choose your own body, would you go with the one you were born with? That's an especially important question for gender fluid or transgender people. The topic was only hinted at in the first season, but Altered Carbon creator Laeta Kalogridis told The Wrap it's something she would like to explore in greater detail. https://en.wikipedia.org/wiki/Altered_Carbon_(TV_series)#Themes https://en.wikipedia.org/wiki/Altered_Carbon_(TV_series)#The...
    - tehlike 7y ago
      I would also be curious about the impact of the divergence of branches. Like in git forks or branches diverging This would be the perfect research testbed for human psychology and intelligence. Do something, compare with exact but unmodified state.
- dmos62 7y ago
  There are some documentations of incarnation and related phenomenon, ranging from anecdotal to quite convincing. So I'd say that the disk might not be critical; humans maybe can boot from network.
nabla9 7y ago
Irreversible brain damage or death occurs when the brain is not getting enough oxygen. If the brain continues its metabolism without oxygen it induces neuronal cell death. The mechanism is called anoxic depolarization. Sodium–potassium pumps in the cell walls need to work to maintain K+ and Na+ ion gradient. When the pump runs out of energy it causes glutamate and aspartate concentrations inside the cell grow. When they grow past some critical threshold, it starts programmed cell death. Cooling he body and brain can prevent this when the brain metabolism slows down to match the lower oxygen levels.

by Tepix 7y ago

So, I still don't know if you are irreversibly dead if your brain stops all activity. I.e. is the state of your brain preserved just by the connections of the neurons? Or is the "RAM" also critical?

adrianN 7y ago

Electrocuting the brain like in electroshock therapy most likely wipes any electrical activity. That seems to indicate that the brain is able to recover after such an event.

mkesper 7y ago

When your brain doesn't get oxygen it will die. See https://en.wikipedia.org/wiki/Cerebral_hypoxia https://en.wikipedia.org/wiki/Cerebral_hypoxia

unnouinceput 7y ago
It's more then that in this case. She had not vital signs at all, heart not beating and providing oxygen included.
- pc86 7y ago
  The brain was provided oxygen, just not by her heart.
  - meowface 7y ago
    Also, perhaps during such a cold state more cells are able to stay alive despite having less oxygen to work with? Maybe due to a reduction in how much energy they use or need per unit time? Just speculating.
    - heavyset_go 7y ago
      Cell death is a metabolic process and it can be arrested if overall metabolism is arrested, as well.
- Teandw 7y ago
  It's important to note that she had no 'detectable' vital signs. Not that she didn't have any vital signs. Very important difference.

ad404b8a372f2b9 7y ago

What leads to brain damage, as I understand it, is lack of oxygen like all other organs and hypothermia reduces your brain activity and its consumption of oxygen but I always interpreted brain activity as an indicator of oxygen consumption and not as something that'd have a cause-effect relationship with brain damage.

vo2maxer 7y ago

Here is an interesting review of the definitions of death: https://academic.oup.com/jlb/article/3/3/743/2327864 https://academic.oup.com/jlb/article/3/3/743/2327864

me_me_me 7y ago

>Or is the "RAM" also critical? There are cases of people without short term memory. That to me qualifies as RAM, guess its not critical to survival.

missosoup 7y ago
Short term memory is more akin to cache. The connections between the neurons is the architecture. The neurons themselves have state. If that state is wiped across the brain, I'd be surprised if the body connected to it could even still keep itself alive. To the actual question though, neurons die/fail very quickly at their normal metabolic rate without an oxygen supply. You are certainly dead once that happens. These procedures are all about providing some oxygen and dropping the metabolic rate to keep the neurons alive longer than they would unassisted.

OscarCunningham 7y ago

Lightning strikes don't wipe people's personalities. Also during epileptic seizures people's neurons fire in abnormal ways, but then return to normal afterwards. So I'd say that the RAM isn't critical; humans can boot from disk.

navaati 7y ago
> humans can boot from disk Now I want to read a sci-fi book with this sentence in it.
- TheSpiceIsLife 7y ago
  Alter Carbon: A key concept in Netflix's cyberpunk series Altered Carbon is the 'stack', an advanced hard drive installed on the brainstem on which a person can save a copy of their consciousness. The main effect of stack technology is a form of immortality, because a stack can be installed into another body if the original body dies. But there’s another a major implication only hinted at during the first season of Altered Carbon: If you could choose your own body, would you go with the one you were born with? That's an especially important question for gender fluid or transgender people. The topic was only hinted at in the first season, but Altered Carbon creator Laeta Kalogridis told The Wrap it's something she would like to explore in greater detail. https://en.wikipedia.org/wiki/Altered_Carbon_(TV_series)#Themes https://en.wikipedia.org/wiki/Altered_Carbon_(TV_series)#The...
  - tehlike 7y ago
    I would also be curious about the impact of the divergence of branches. Like in git forks or branches diverging This would be the perfect research testbed for human psychology and intelligence. Do something, compare with exact but unmodified state.
dmos62 7y ago
There are some documentations of incarnation and related phenomenon, ranging from anecdotal to quite convincing. So I'd say that the disk might not be critical; humans maybe can boot from network.

nabla9 7y ago

Irreversible brain damage or death occurs when the brain is not getting enough oxygen. If the brain continues its metabolism without oxygen it induces neuronal cell death. The mechanism is called anoxic depolarization. Sodium–potassium pumps in the cell walls need to work to maintain K+ and Na+ ion gradient. When the pump runs out of energy it causes glutamate and aspartate concentrations inside the cell grow. When they grow past some critical threshold, it starts programmed cell death. Cooling he body and brain can prevent this when the brain metabolism slows down to match the lower oxygen levels.