On Tuesday, January 22, 2013 8:53:17 AM UTC-5, stathisp wrote:
> On Tue, Jan 22, 2013 at 1:09 AM, Craig Weinberg
> >> Do you disagree that swapping a carbon atom for another carbon atom in
> >> the brain will leave brain function and consciousness unchanged?
> > I don't believe that we will necessarily know that our consciousness is
> > changed. Even LSD takes a few micrograms to have an effect that we
> > Changing one person in the city of New York with another may not change
> > city in any appreciably obvious way, but it's a matter of scale and
> > proportion, not functional sequestering.
> >> The field of nuclear medicine involves injecting radiolabeled
> >> chemicals into subjects and then scanning for them with radiosensitive
> >> equipment. This is how PET scanners work, for example. The idea is
> >> that if the injected chemical is similar enough to normal biological
> >> matter it will replace this matter without affecting function,
> >> including brain function and consciousness. You could say this is a
> >> practical application of the theory that consciousness is
> >> substrate-independent, verified thousands of times every day in
> >> clinical situations.
> > That's because the radioactivity is mild. Heavy doses of gamma radiation
> > not without their effects on consciousness. Anything that you do on the
> > nuclear level can potentially effect the chemical level, which can
> > the biological level, etc. These levels have different qualities as well
> > quantitative scales so it is simplistic to approach it from a
> > quantitative-only view. Awareness is qualities, not just quantities.
> Obviously, if the change you make to the brain changes its function it
> could also change consciousness. This is the functionalist position.
The functionalist position implies that function alone generates
consciousness. My position is that consciousness itself is the generator,
not the generated. This does not mean that the brain does not provide
consciousness with access to a human quality experience - it does, along
with providing a lot of living cells and organic molecules with experience
on their own levels as well.
> You have claimed that this is wrong, and that no matter how closely a
> replacement brain part duplicates the function of the original there
> will be a change in consciousness,
Not exactly. I say that there is no such thing as duplication in an
absolute sense. When something seems similar enough to another thing, we
can say that it has been duplicated, but this is a function of our pattern
recognition capacities. This is not an issue for most forms and functions
which we produce, but that's because there are no other forms or functions
which are *us*. That little detail changes everything, and it is the same
detail which makes us aware of consciousness in the first place.
Because I understand that consciousness is not produced by a function of
the brain, (the brain is used as a vehicle to participate in many conscious
experiences), I can see the flaw in the reasoning which assumes that the
self can be replaced. This is not some sentimental attachment for the
sacredness of the self, rather it is a clear apprehension of the ontology
of subjectivity as private physics. You can replace the function of a limb
with a prosthetic limb, but you have not replaced the limb. You can
simulate the function of a fireplace with concrete 'logs' and and a heat
source, but you have not replaced the fireplace. All you have done is
satisfied some limited expectations of certain sense channels. You cannot
replace a person's head or brain in their entirety because there is nothing
left of the person which you are trying to convince has been replaced.
Replacement is a function of mechanistic expectation, not the concrete
reality of physics.
> simply because it isn't the
> original. If this were so, you would expect a change in consciousness
> when atoms in the brain are replaced with different isotopes, even if
> the isotopes are not radioactive. And yet this is not what happens.
No, that is not what I would expect at all. If you made a few people in New
York City wear the same yellow hats, would you expect New York City to be
changed? How about if you got rid of all the people and replaced them with
audioanimatronic mannequins that wear yellow hats instead? See the
The scientific explanation is that chemistry is for the most part
> unaffected by the number of neutrons in the nucleus, and that since
> the brain works by means of chemical reactions, brain function and
> hence consciousness are also unaffected.
But the brain works by means of experiences as well. If I say something
that makes you mad, your brain chemistry is changed - not by chemistry, but
by your interpretations of my intentions and meanings. It's true that
events on different layers of public and private physics have highly
specific ways of interacting, but that doesn't mean that we can replace a
brain stem with a plastic computer and expect that the conscious person
> It's not that there is
> anything magically consciousness-preserving about switching isotopes,
> it's just that switching isotopes is an example of part replacement
> that makes no functional difference, like replacing a part in your car
> with a new part that is 0.001 mm bigger.
I understand, but consciousness isn't a function. It is elaborated through
function, but without some kind of original perception-participation, there
is no difference between a function and no function. Without the history of
perceived experience there can be no coherent identity. Since we know that
brain damage can disrupt a person's identity, we can assume that the brain
is not infinitely plastic and tolerant. Even transplanted organs suffer the
chance of rejection. Why then should we assume that something which
functions to create experiences in ways which we have no understanding of
could be 'replaced' or 'duplicated' by something which bears no resemblance
for a biological organism?
The tolerance of a biological organism to nuclear variation is high, maybe
infinitely so. As long as a zygote made of alternate isotopes grows into a
healthy baby, I would expect that such a baby would be indistinguishable
from any other, although I would not be surprised if was not that simple
either. The tolerance changes as you go up the ladder though. Molecules are
very particular about how they combine. Cells are even more particular in
some ways. Organisms even require abstract social conditions to nurture
them into a healthy state. Just because the gross structure of the
factory-like aspects of the brain could be modeled does not mean that the
content of the personal experience which that factory serves would be
The range of phenomena in the universe runs from the generic to the
proprietary. Until we understand exactly why that is, and why it seems so
important, there is no reason to assume that one can simply be substituted
for the other. You would not replace the bricks of the Taj Mahal with
bricks of ripe bananas, even though they may function the same way for a
while in small amounts. That is the level of error I think we are dealing
with in the assumption of inorganic brains.
> Stathis Papaioannou
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