4 ms·

Ask HN: Do brains deadlock?

2 points by FlowNote 8y ago

Massively parallel processing and zero deadlocks? That's curious.

blackflame7000 8y ago
It could be argued that someone in a coma is in a deadlocked state
eesmith 8y ago
https://en.wikipedia.org/wiki/Buridan%27s_ass https://en.wikipedia.org/wiki/Buridan%27s_ass and https://en.wikipedia.org/wiki/Analysis_paralysis https://en.wikipedia.org/wiki/Analysis_paralysis ?
- FlowNote 8y ago
  Do either of these, say, shut off the nervous system from the lungs or the stomach? Deadlocking the brain should appear in the underlying autonomous nervous system, but it doesn't. That's very odd.
  - eesmith 8y ago
    Do you also find it odd that deadlocking a computer doesn't cause the cooling fans to stop and RAM refresh cycle to fail? That is, what is the basis of "should"? We have computer systems with a hardware watchdog. If the keep-alive heartbeat fails - like when the CPU deadlocks - it resets the computer. https://en.wikipedia.org/wiki/Watchdog_timer https://en.wikipedia.org/wiki/Watchdog_timer Computers have multiple systems to help prevent total system shutdown. Why can't humans also have such?
    - FlowNote 8y ago
      The autonomic system doesnt have a global observer doing that job. No part of the brain has watchdogs to make sure it keeps doing what it's supposed to be doing. You instantly hit the homunculus problem assuming the brain had another brain watching it because then it would need another brain to watch that, ad infinitum.
      - eesmith 8y ago
        That's all fine and good, but you didn't understand my argument. I was objecting to your assertion that a "deadlock" would necessarily cause the autonomous nervous system to fail. Since computers don't do that, why do you think that evolved systems - which have billions of years to build up robustness - must do that? Your objection to the "homunculus problem" is not relevant. A watchdog does not need to be a "brain" in any but the most poetic sense. It can be switch on a timer, where the timer is reset by the system. Computer can have deadlocks on many levels. I could write a multi-threaded program which deadlocks. Even though that's frozen, the rest of the computer could act like normal. Since you didn't specify which sort of deadlock you were looking for, I pointed to ones which occur at the most recently evolved parts of the brain.
        FlowNote 8y ago
        And you haven't addressed the implied global scope your hypothetical neural watchdog requires. Find a global watchdog behaving in the manner you describe within any neural system for any animal at any period in the history of Earth's biosphere. Find any "neural system resetting" anywhere, in fact.
        eesmith 8y ago
        Shrug That wasn't the point. You said that if computers act like X then why don't humans act like X. I pointed out some cases where humans acted a bit like X. You then asked why those cases weren't also Y. I pointed out that computers aren't always also Y, so why did you think that humans with X must also be Y? I am not implying a global watchdog, for the simple reason that distributed computing systems can have local watchdogs which reset a node when the node is not active, even without global intervention. The mechanisms can be different - animals swim while submarines don't, but both move underwater. My point was that I disagreed with your intuition and conclusion, and since I can find one counter-example to show that X doesn't imply Y, you can't conclude that X must imply Y. Nor can you conclude my counter-example is the only possible mechanism. You still haven't described the basis for your intuition.
opless 8y ago
maybe this is relevant? https://www.youtube.com/watch?v=PWMMcaF7YPQ https://www.youtube.com/watch?v=PWMMcaF7YPQ
zzzcpan 8y ago
It's more like massive amount of reactive asynchronous communicating processes, where deadlocks cannot happen. Even if two processes accidentally enter a loop where they react by sending messages to each other, they still will be able to react to messages from other processes.
- cimmanom 8y ago
  This. Or maybe epilepsy?
masonic 8y ago
"Nice try, but my head was built with paradox-absorbing crumple zones." -- Robot Santa on "Futurama"

2 points by FlowNote 8y ago

Massively parallel processing and zero deadlocks? That's curious.

blackflame7000 8y ago

It could be argued that someone in a coma is in a deadlocked state

eesmith 8y ago

https://en.wikipedia.org/wiki/Buridan%27s_ass https://en.wikipedia.org/wiki/Buridan%27s_ass and https://en.wikipedia.org/wiki/Analysis_paralysis https://en.wikipedia.org/wiki/Analysis_paralysis ?

FlowNote 8y ago
Do either of these, say, shut off the nervous system from the lungs or the stomach? Deadlocking the brain should appear in the underlying autonomous nervous system, but it doesn't. That's very odd.
- eesmith 8y ago
  Do you also find it odd that deadlocking a computer doesn't cause the cooling fans to stop and RAM refresh cycle to fail? That is, what is the basis of "should"? We have computer systems with a hardware watchdog. If the keep-alive heartbeat fails - like when the CPU deadlocks - it resets the computer. https://en.wikipedia.org/wiki/Watchdog_timer https://en.wikipedia.org/wiki/Watchdog_timer Computers have multiple systems to help prevent total system shutdown. Why can't humans also have such?
  - FlowNote 8y ago
    The autonomic system doesnt have a global observer doing that job. No part of the brain has watchdogs to make sure it keeps doing what it's supposed to be doing. You instantly hit the homunculus problem assuming the brain had another brain watching it because then it would need another brain to watch that, ad infinitum.
    - eesmith 8y ago
      That's all fine and good, but you didn't understand my argument. I was objecting to your assertion that a "deadlock" would necessarily cause the autonomous nervous system to fail. Since computers don't do that, why do you think that evolved systems - which have billions of years to build up robustness - must do that? Your objection to the "homunculus problem" is not relevant. A watchdog does not need to be a "brain" in any but the most poetic sense. It can be switch on a timer, where the timer is reset by the system. Computer can have deadlocks on many levels. I could write a multi-threaded program which deadlocks. Even though that's frozen, the rest of the computer could act like normal. Since you didn't specify which sort of deadlock you were looking for, I pointed to ones which occur at the most recently evolved parts of the brain.
      - FlowNote 8y ago
        And you haven't addressed the implied global scope your hypothetical neural watchdog requires. Find a global watchdog behaving in the manner you describe within any neural system for any animal at any period in the history of Earth's biosphere. Find any "neural system resetting" anywhere, in fact.
        eesmith 8y ago
        Shrug That wasn't the point. You said that if computers act like X then why don't humans act like X. I pointed out some cases where humans acted a bit like X. You then asked why those cases weren't also Y. I pointed out that computers aren't always also Y, so why did you think that humans with X must also be Y? I am not implying a global watchdog, for the simple reason that distributed computing systems can have local watchdogs which reset a node when the node is not active, even without global intervention. The mechanisms can be different - animals swim while submarines don't, but both move underwater. My point was that I disagreed with your intuition and conclusion, and since I can find one counter-example to show that X doesn't imply Y, you can't conclude that X must imply Y. Nor can you conclude my counter-example is the only possible mechanism. You still haven't described the basis for your intuition.

opless 8y ago

maybe this is relevant? https://www.youtube.com/watch?v=PWMMcaF7YPQ https://www.youtube.com/watch?v=PWMMcaF7YPQ

zzzcpan 8y ago

It's more like massive amount of reactive asynchronous communicating processes, where deadlocks cannot happen. Even if two processes accidentally enter a loop where they react by sending messages to each other, they still will be able to react to messages from other processes.

cimmanom 8y ago
This. Or maybe epilepsy?

masonic 8y ago

"Nice try, but my head was built with paradox-absorbing crumple zones." -- Robot Santa on "Futurama"