A computed theory of a hurricane is not a hurricane.
A computed theory of cognition is not cognition.
We don't want a simulation of the thing.
We want an instance of the thing.
-----Original Message-----
From: everything-list@googlegroups.com
[mailto:everything-list@googlegroups.com] On Behalf Of meekerdb
Sent: Wednesday, 3 August 2011 2:19 PM
To: everything-list@googlegroups.com
Subject: Re: Simulated Brains
On 8/2/2011 4:00 PM, Stephen P. King wrote:
On 8/2/2011 6:08 PM, meekerdb wrote:
On 8/2/2011 2:44 PM, Stephen P. King wrote:
On 8/2/2011 5:26 PM, meekerdb wrote:
On 8/2/2011 2:08 PM, Stephen P. King wrote:
On 8/2/2011 4:04 PM, meekerdb wrote:
On 8/2/2011 12:43 PM, Craig Weinberg wrote:
On Aug 2, 2:06 pm, "Stephen P. King"<stephe...@charter.net>
wrote:
The point is that there is a point where the best
possible model or
computational simulation of a system is the system itself. The
fact that
it is impossible to create a model of a weather system that
can
predict
*all* of its future behavior does not equal to a proof that
one
cannot
create an approximately accurate model of a weather system.
One has to
trade off accuracy for feasibility.
I agree that's true, and by that definition, we can certainly
make
cybernetic systems which can approximate the appearance of
consciousness in the eyes of most human clients of those
systems
for
the scope of their intended purpose. To get beyond that level
of
accuracy, you may need to get down to the cellular, genetic, or
molecular level, in which case it's not really worth the
trouble
of re-
inventing life just to get a friendlier sounding voicemail.
Craig
So now you agree that a simulation of a brain at the molecular
level would suffice to produce consciousness (although of course
it would be much more efficient to actually use molecules
instead
of computationally simulating them). This would be a good
reason to say 'no' to the doctor, since even though you could
simulate the molecules and their interactions, quantum
randomness
would prevent you from controlling their interactions with the
molecules in the rest of your brain. Bruno's argument would
still go through, but the 'doctor' might have to replace not
only
your brain but a big chunk of the universe with which it
interacts. However, most people who have read Tegmark's paper
understand that the brain must be essentially classical as a
computer and so a simulation, even one of molecules, could be
quasi-classical, i.e. local.
Brent
Hi Brent,
I wonder if you would make a friendly wager with me about the
veracity of Tegmark's claims about the brain being "essentially
classical"? I bet $1 US (payable via Paypal) that he is dead
wrong
*and* that the proof that the brain actively involves quantum
phenomena that are discounted by Tegmark will emerge within two
years. We already have evidence that the photosynthesis process
in
plants involves quantum coherence, there is an experiment being
designed now to test the coherence in the retina of the human
eye.
http://www.ghuth.com/2010/02/03/another-finding-of-quantum-coherence-in-
a-photosynthetic-biological-system/
http://www.ghuth.com/2011/04/24/quantum-coherence-and-the-retina/
Those are not really to the point. Of course the brain involves
quantum processes and some of these involve coherence for short
times. But Tegmark argues that the times are too short to be
relevant to neural signaling and information processing. There's
an implicit assumption that neural activity is responsible for
thought - that the 'doctor' could substitute at the neuron level.
I think this is right and it is supported by evolutionary
considerations. We wouldn't want an intelligent Mars Rover to
make
decisions based on quantum randomness except in rare circumstance
(like Buridan's ass) and it wouldn't be evolutionarily
advantageous
for an organism on Earth. I'm glad to accept your bet; except
that
I'm not sure how to resolve it. It don't think finding something
like the energy transfer involving coherence in photosynthesis or
photon detection is relevant.
No, my thought is that quantum coherence accounts for, among
other things, the way that sense data is continuously integrated
into a whole.
What integrated whole do you refer to? Our memory of a life? How
does it account for it?
This is not rocket surgery, come on! Think! Did you ever happen to
notice that, modulo variations in distance, the sounds you hear, the
things you see, feels, taste, etc. are all integrated together? How
is
it that, modulo deya vu and similar synesthesias and dislexia, the
brain generates a vritual reality version of the world around you
that
is amazingly free of latency? While there are visual effects that
replicate aliasing effects, such as when we see the spokes of a wheel
turning backwards, the ability of the brain to turn all those signals
into a single and integrated virtual world is amazing, but more
amazing still is the fact that there is something in the brain that
acts like an observer, something that lead many in the past to
speculate about a homunculus...
This world view is not necessarily so integrated. If you've ever been
in a car crash you'll know that you hear the sound before the sights
that go with it. This comports with Dennett's point that the brain
puts
things together with time stamps. But what does quantum coherence
have
to do with this - it's something you would do with a classical
computer
that had modules for different perceptions with different processing
times.
This leads to a situation that Daniel C. Dennett calls the
"Cartesian Theater". Dennett's proof that it cannot exist because
it
generates infinite regress of homunculi inside humonculi is flawed
because such infinities can only occur if each of the humonculi has
access to sufficient computational resources to generate the rest
of
them. When we understand that computations require the utilization
of resources and do not occur 'for free' we see that the entire
case
against situations that imply the possibility of infinite regress
fails.
I don't understand that. Are you agreeing with Dennett that an
infinite regress cannot occur or are you arguing that the need to
pay
for resources makes them possible?
Dennet'ts argument in Consciousness Explained centers around
building up and then knocking down the "Cartesian Theater", based on
the supposed fact that it generates an infinite regress. My claim is
that his argument loses it motivation since the brain does not have
the computational resources to generate a regress of arbitrary depth.
It needs only to only generate a regress that is 3 or 4 levels deep.
Marius Buliga has an interesting blog post about some of Dennett's
issues here:
http://chorasimilarity.wordpress.com/2011/06/06/the-cartesian-theater-ph
ilosophy-of-mind-versus-aerography/
The idea is that we can in fact have simulations withing
simulations within simulations without the problematic infinite
regress. A model of Self within a model of self + world is not a
problem, pace Dennett.
Quantum phenomena is NOT all about randomness. Frankly I would
really like to understand how that rubbish of an idea still is
held
in seriously thinking people! There is not randomness in QM, there
in only the physical inability to predict exactly when some quantum
event will occur in advance. It is because QM system cannot be
copied that makes it impossible to predict their behavior in
advance, not because of some inherent randomness!
Sounds like a distinction without a difference. It's still a good
reason for evolution to favor a quasi-classical brain.
There are effects within QM that do not exist in the classical
regime, effects that can be used to do things that classical systems
cannot do. I am drawing from unpublished work by a friend of mine
so I
cannot give more details on this unfortunately. :-(
Take the infamous radioactive atom in the Schrodinger Cat box. Is
its decay strictly a "random" phenomena? Not really! QM says not
one
word about randomness,
See Born's projection postulate.
Note the word "postulate". The Born postulate is added to the QM
formalism as a means to explain probabilities.
Not exactly. It provided a probabilistic interpretation Schrodinger's
wave function - without which wave mechanics would have been unusable.
Its status is controversial and not settled at all even today!
Indeed. There have been many attempts to derive, rather than
postulate,
it. But they all seem to make some equally questionable postulate.
Nevertheless its use is fundamental in all applications.
How many texts books on QM have you read? I recommend Bohm's.
A few. I recommend Asher Peres or Ballentine. Zee or Wald for QFT.
Bohm's version of QM cannot be extended to a relativistic theory since
it includes a non-local "guidance" field.
it only allows us to calculate the half-life of said atom and that
calculation is as good as is possible given the fact that we cannot
generate a simulation of that atom and its environment and all of
the interactions thereof in a way that we can get predictions about
its behavior in advance.
As to your post here. Craig's point is that the simulated
brain, even if simulated down to the molecular level, will only
be
a simulation and 'think simulate thoughts'. If said simulated
brain has a consiousness it will be its own, not that some other
brain.
Craig's position seems to be more a blur than a point. He has
said
that only biological neurons can instantiate consciousness and
only
a conscious being can act like a conscious being. That would
imply
that a being with an artificial, e.g. silicon chip based, brain
cannot act like a conscious being.
You care completely failing to understand that Craig is not
stuck in the box of canned answers to questions about the kinds of
things that we discuss in this List. While I will quibble with the
claim that "biological neurons can instantiate consciousness" as I
believe that consciousness is not just a 'phenomena of carbon based
chemistry', it is obvious that 'only a conscious being can act like
a conscious being", that follows from the basic principle of
Identity. A thing is itself and it behaves as itself would. A
trivial fact but one that gets ignored too often.
A consciousness can no more be copied than the state of a QM
system.
That's the point in question. If Tegmark is right, it can.
Tegmark is wrong.
But you have not proposed any way to resolve the bet.
Pfft, whatever. Re-read what I wrote. Are you just trying to
demonstrate that you are the smartest guy in the room or are you
genuinely interested in figuring out how Everything works?
I'm just interested in how we would decide who won? If there is some
test you can suggest or some theoretical development you anticipate it
would be very relevant to the question of the philosophical zombie.
Brent
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