
Ask HN: Do brains deadlock? - FlowNote
Massively parallel processing and zero deadlocks? That&#x27;s curious.
======
eesmith
[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
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
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
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
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
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
_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.

~~~
FlowNote
Distributed systems also deadlock in ways that local watchdogs can't account
for. You still imply the global watchdog of _the brain of the systems
designer_ to navigate those problems.

All of your examples _require_ a human homunculus to steer a system away from
deadlocking.

The brain doesn't have an architectural homunculus to do that for it, and yet,
it does not deadlock in any way resembling the deadlocks we see in computer
science.

My question is how did the brain do this without a system architect? How can
natural selection have a bias that prevents deadlocking in neural
compositions?

~~~
eesmith
While you haven't expressed the source of your intuition, based on your
answers, you see the architecture of human-designed systems, which are
engineered based on economic considerations, as being predictive of what
natural systems are like.

This is not, generally speaking, true.

Even when built on standard computing architecture, we see that designs
influenced by evolutionary design can result in "bizarre, mysterious, and
unconventional" designs. I'm quoting from Thompson and Layzell's "Analysis of
Unconventional Evolved Electronics" (1999). In that paper, note that the
evolve system had a different response to temperature change than the "brittle
failure" of normal digital circuits. System crashes like what you describe are
"brittle".

Evolution, by human design senses, is incredibly wasteful. We are not going to
build computers or distributed computing systems that way, hence any intuition
based on those design principles are likely not applicable.

You asked "How can natural selection have a bias that prevents deadlocking in
neural compositions?"

The "how" is easy - organisms with hard crashing deadlocks don't reproduce.

You want to know what that mechanism is, which is a different question.

If you really want to understand this, you'll have to talk to biologists who
focus on this sort of topic, not a "hacking news" sites.

------
masonic
"Nice try, but my head was built with paradox-absorbing crumple zones."

\-- Robot Santa on "Futurama"

------
zzzcpan
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
This.

Or maybe epilepsy?

------
blackflame7000
It could be argued that someone in a coma is in a deadlocked state

------
opless
maybe this is relevant?
[https://www.youtube.com/watch?v=PWMMcaF7YPQ](https://www.youtube.com/watch?v=PWMMcaF7YPQ)

