On Fri, Oct 14, 2011 at 9:39 AM, Craig Weinberg <whatsons...@gmail.com> wrote:

>> The external inputs themselves are not modelled, they are provided by
>> the environment.
>
> What is an 'external input' made of? Are you saying that there are
> physical pieces of the outside world stuck inside of your brain?

The outside world interacts with your brain and causes physical changes in it.

>> > If consciousness were epiphenomenal and supervenient on mechanistic
>> > processes, you would not have a choice whether or not to worry. You
>> > would have no opinion, and there could be no such thing as an opinion.
>> > My objection is that it's a nonsensical position.
>>
>> It's not nonsensical: I can understand it and it is not self-contradictory.
>
> It's directly contradictory. If everything is either deterministic or
> random, where does an opinion come from?  What would be the function
> of an opinion in such a world?

Everything *is* either deterministic or random. A third alternative is
conceptually impossible. It's not a matter of scientific discovery,
it's an a priori fact, like the truths of arithmetic. The debate about
free will is a debate about whether free will is compatible with
determinism or whether randomness is required; it's not a debate about
whether neither-determined-nor-random exists.

I can't understand your puzzlement at where an opinion comes from and
what its purpose is in a determined or random world. No-one else sees
it as a problem, so why do you? Even if we had an immaterial soul and
science showed that neurons fired magically due to the influence of
this soul our decisions would have to be either determined or random,
since that's all there is.

>> "I" am the result of the activity of the ensemble of neurons in my
>> brain.
>
> Why does the activity of neurons 'result' in something other than what
> it is? Why can't it just as easily be that the activity of neurons in
> the brain is the result of the activity of the 'I'? If you have no
> idea whatsoever what the 'result' of subjectivity is, how do you know
> that it isn't making choices that are passed down the nervous system,
> starting from the brain?

When a billiard ball hits another billiard ball how do you know that
this isn't as a result of the balls' subjectivity rather than the
other way around?

>> Subjectivity results because that is what it feels like when
>> information is processed the way it is in the brain.
>
> Why should it feel like anything? How could there be any such thing as
> feeling at all? If your view of neurology were true, there could be no
> phenomena in the brain which is not explained by chemistry and physics
> - how do you explain 'feeling' in terms of neuron function? How does
> it magically get connected to the brain? Even if you say that feeling
> is an illusion, how does that change the fact that it's part of the
> cosmos? How do you account for it?

The illusion of feeling is still the feeling, so it is nonsensical to
say that feeling is an illusion. It's a puzzle that feeling exists at
all; David Chalmers calls this the "Hard Problem" of consciousness. It
doesn't solve the puzzle to say that feeling is a fundamental aspect
of the universe, since you can always ask, "Why is feeling a
fundamental aspect of the universe?"

>>"Choice" is when
>> I have two alternatives and I feel I can freely choose between them,
>
> I agree. Choice is a feeling of being able to select a motive to
> actualize from a group of motives.
>
>> which is consistent with the decision being ultimately either random
>> or determined.
>
> Huh? No, it's consistent with the decision being intentional and
> voluntary.

Being intentional and voluntary is entirely consistent with the
decision being either determined or random, since they are the only
two choices. You can't decide to create another category like "married
bachelor" just because you fancy the sound of it.

> If it were random or determined, any kind of feeling about it one way
> or another would be unexplainable. It wouldn't even be magic because
> magic at least has a purpose. It is to say that a box of paperclips
> just happens to have a memory of doing a Jack Nicholson impersonation
> at a party in 1986, and since that's the case, it must help keep the
> paperclips from oxidizing or something.

That's a non sequitur.

>> The action potential is the spike in potential difference between the
>> two sides of a cell membrane that propagates down the membrane,
>> generating an electromagnetic field.
>
> If you want to understand awareness you have to go deeper than that.
> You have to question what an action potential and electromagnetic
> field actually are. I think that you will find that we have no idea
> what they are, or how one atom knows that another atom has too few or
> too many electrons. What you are saying now is basically 'the water
> comes out of the faucet when the valve turns from one side to the
> other, which generates a volume of water that propagates down the
> drain'. It tells us nothing about why the faucet turns in the first
> place.
>
> Your description doesn't even allow for the ordinary functioning of
> cellular biology let alone neurology. You make no distinction between
> living tissue and falling leaves, seeing each as equally passive to
> random currents outside of themselves. That's not how cells work. They
> are small animals. They survive, grow, etc. They don't just cycle
> mechanically at the mercy of outside circumstances.

Cells are just little machines made of organic molecules. Vitalism was
discredited in the nineteenth century.

>> > Do you agree that neurological activity corresponds to human
>> > perceptions?
>>
>> Yes.
>>
>> > Do you agree that neurological activity is chemical and electrical
>> > activity?
>>
>> Yes.
>>
>> > Do you agree that chemical and electrical activity are both forms of
>> > electromagnetic activity?
>>
>> Chemistry is ultimately the result of the electromagnetic force.
>>
>> > If so, then it is not possible that human perceptions are not in some
>> > way electromagnetic.
>>
>> I don't know in what sense it is accurate to say that.
>
> Why not? I just laid it out for you. We observe that electromagnetic
> activity in the brain is precisely synchronized with perception. We
> observe that electromagnetic activity is an excitation of cells, which
> is chemical, which is electromagnetic. If perception is
> electromagnetic at all, then electromagnetism must also partially be
> perception.
>
>> Consciousness
>> is somehow different to the brain activity, though some hard core
>> reductionists insist that it is identical to it and there is nothing
>> further to explain.
>
> You are trying to have it both ways. You say that nothing in the brain
> can occur except brain activity, yet you say consciousness is somehow
> different from brain activity. It sounds like you believe in a
> disembodied soul?

Consciousness is not identical to brain activity. You can touch the
brain, but you can't touch consciousness. The equivalent is the
electrical activity of a computer compared to the computation.

>> >> There are two types of ion channels, voltage-dependent and
>> >> ligand-dependent. The votage-activated ones open when the potential
>> >> difference across the membrane is at a certain level:
>> >> the electric
>> >> field generated as a result of this potential difference changes the
>> >> shape of the ion channel, which is a transmembrane protein, and this
>> >> opens the channel to allow the specific ion to pass through.
>>
>> > What changes the potential difference in the first place? What relates
>> > any of that to our subjective experience?
>>
>> >> Ligand-activated ion channels open when a specific neurotransmitter
>> >> binds. The transmembrane potential changes as a result of ion fluxes:
>> >> potassium is more concentrated inside the cell so when potassium ion
>> >> channels open potassium ions exit leaving the inside more negative,
>> >> while sodium is more concentrated outside the cell so when sodium
>> >> channels open sodium ions enter making the inside more positive. The
>> >> sodium and potassium fluxes are responsible for depolarisation, the
>> >> action potential and repolarisation. There can't be an action
>> >> potential without these ion fluxes, there can't be ion fluxes without
>> >> the ion channels opening and closing, and the ion channels can't open
>> >> and close without the appropriate voltage or neurotransmitter
>> >> stimulus. Spontaneously active neurons have voltage-activated ion
>> >> channels that open at the cell's resting potential.
>>
>> > All of these processes supervene upon the spontaneous changes to
>> > electromagnetic conditions. You are talking as if the brain is just a
>> > sponge which fills up with electrolytes and discharges them regularly
>> > without any control over the process. If you can move your finger
>> > deliberately, then that means that the neurons associated with that
>> > movement are also being depolarized intentionally - through sentience
>> > and actively engaged teleology, not just passive inertia. You don't
>> > have to keep reciting neurology 101 to me, I can read Wikipedia too.
>>
>> I have given a basic account of the electrophysiology of neurons
>> because you don't seem to understand it,
>
> Why do you think that I don't understand it? It's simple. Microscopic
> pores open and close in cell membranes because of their voltage
> status, releasing "charged" molecules (ions) for no reason other than
> they automatically do that when the physical conditions match those
> which it's programmed to be triggered by. If you get enough of them
> doing this at the same time, a nothing-like something begins to think
> that it exists, and hallucinates a world of streets, music, Fred
> Flinstone, and rhubarb when all that really exists is neurochemistry
> mindlessly metabolizing itself . Sound about right?

That's about right. It's what happens whether you like it or not.

> Again, what you are overlooking again and again is where this
> meaningless chain of mechanism begins and ends. What is charge? Why
> does one atom having more or less electrons mean anything at all to
> another atom?  We don't know. All we know is that we can plot out
> patterns in space which correlate to patterns in matter which can be
> detected in other material instruments. To me it's obvious that charge
> is a sensorimotive experience on the molecular level. Attraction and
> repulsion between molecules have a subjective quality to the molecules
> involved. There is no electromagnetic field at all. What changes the
> voltage of an ion channel is how the neuron feels (and/or how it is
> made to feel by other neurons, substances, etc.). How the neurons feel
> is how we feel. We are the feelings of the neurons in our brain.

That sounds a bit bizarre but even if true, it makes no difference to
the observation of neurological events. The cell does not depolarise
magically, but due to clearly understood (for half a century)
biochemical causes.

>> and you still don't, since
>> you ask above "what changes the potential difference in the first
>> place?" The membrane potential changes due to the balance of positive
>> and negative ions, and the ions move passively by diffusion through
>> the membrane and through ion channels and actively as the result of
>> energy-dependent ion pumps such as sodium-potassium ATPase.
>
> How do you know that the membrane potential doesn't also cause the
> changes in the balance of positive and negative ions? If you
> electrocute a frog's leg, you are changing the membrane potentials
> directly. That's what your mind does - it changes the membrane
> potentials directly, because it is the membrane potentials of billions
> of membranes at once. As you said, 'the result of the activity of the
> ensemble of neurons in your brain'. For some reason you're just stuck
> on this bizarre misconception of the cosmos that high level phenomena
> can only arise from low level phenomena and not the other way around,
> even though that is clearly not our ordinary experience of voluntary
> vs involuntary control of our body.

The membrane potential *does* cause a change in the balance of
negative and positive ions - that's how an action potential is
generated. If you attach electrodes to a cell you can change the
membrane potential directly, but you can't change it unless you
actually do something to it. Whether the neuron fires or not is
determined by the internal state of the cell and the external inputs,
the most important of these being from other neurons in the network.

>> You have
>> misunderstood what spontaneous neural activity means.
>
> There is no misunderstanding. It's not even controversial, you're just
> plain denying the uncontested facts. Don't you think that if there
> were any other term besides 'spontaneous' that could be used they
> would have used it? Look at the animations. (http://www.youtube.com/
> watch?v=uhCF-zlk0jY)  Can you not see exactly what that is with your
> own eyes? Your impression of neurology being reducible to a passive
> chain reaction running through the brain is not even wishful thinking,
> it's factually incorrect.

I despair at explaining this to you further. Perhaps you could email
some of the authors of the papers and ask them if by "spontaneous"
they mean "without any observable physical cause".

>> You haven't answered what you think actually happens at the molecular
>> level in one of the neurons that spontaneously decides to depolarise.
>> Do sodium channels distort without any force on them to let the ions
>> through, do the sodium ions materialise out of nowhere, or what?
>
> The sodium ions aren't material to begin with. They are just sodium
> with an attitude. We can measure the consequences of that attitude but
> in living organisms, cells are able to change the charge their
> membranes. They can expand and contract in group synchronization, not
> just in response to the presence of electrolytes but through active
> communication and group decision. Are you aware of what quorum sensing
> is?

Quorum sensing involves chemicals that are secreted and act as
neurotransmitters. As explained again and a again and again, for
everything that an organism does, there is a low level mechanistic
explanation.

You continue to avoid explaining what you think actually happens at
the molecular level when the subject's will causes depolarisation. Do
ion channels that will normally only open with at least a 60mV
potential difference across them open even though the potential
difference is only 50mV? If so, that is magic. If not, then the neuron
follows only the mechanistic processes which you have such disdain
for.

> The depolarization can either be due to physiological causes which may
> manifest as a change in the subject's experience, or it can be the
> subject's will which manifests as a depolarization of many neurons at
> once. It looks about the same physiologically, so that whatever
> happens on the molecular level to make me breathe unintentionally is
> no different from the types of processes which happen when I choose to
> change my breathing intentionally.
>
> The only physiological difference is that the signal originates from a
> different part of the brain. Your view has no way to explain why I
> feel that I am in control of my breathing when the signal comes from
> one region, and why I feel nothing when it comes from another,
> especially since they both have the same effect on the same organ. It
> would be redundant to have two separate regions of the brain do the
> exact same thing except one is regular and another comes with 'extra
> zesty metaphysical subjective illusion sauce'.

The voluntary and involuntary muscular control are not "the exact same
thing". Voluntary muscular control involves the cortex and is affected
by cognition, while involuntary is not.


-- 
Stathis Papaioannou

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