On Oct 19, 7:30 pm, Stathis Papaioannou <stath...@gmail.com> wrote:
> On Thu, Oct 20, 2011 at 1:46 AM, Craig Weinberg <whatsons...@gmail.com> wrote:
> >> When you speak about what you see the information carried in the light
> >> that comes into your pupils must somehow get to the motor neurons
> >> controlling your vocal cords. How do you think this happens?
>
> > There is no 'information' carried in the light. There is only the
> > sense that the visual cortex makes of the sense that the retina makes
> > of the sense that the optical relations of the environment make to the
> > person who is using the the visual cortex and retina to perceive the
> > environment. At no point would anything that enters your pupils wind
> > up coming out of your vocal chords through your motor neurons. I am
> > flabbergasted that you can take this view seriously in all honesty.
> > Aren't you saying that you think nuggets of 'information' from outside
> > of your eyeballs are squirting into your brain and out of your throat?
>
> > How I think it happens that we can speak about what I see is that the
> > cells of my retina experience a photosynthetic sense of their
> > environment. The cells of my visual cortex experience a neurological
> > sense of the retina's sense, which it arrives at by sharing it's own
> > sense (image) with the sense of other participating parts of the brain
> > - some conscious, like attention and focus, some subconscious like
> > pattern recognition, and some unconscious like color and motion. The
> > visual cortex is only part of what we experience of sight, the rest is
> > influenced by our expectations and memories, which are the senses of
> > other regions of the brain.
>
> > The overall sensemaking of the brain that we have conscious access to,
> > including limbic feelings, prefrontal cognitions, etc, are all
> > involved in building a consensus - a mutual, bi-directional process
> > between the different channels of sensemaking and the executive
> > intentions. That understanding is all that is communicated through the
> > motor control of the vocal cords. There is no transduced visual
> > 'information' present in our larynx or in the spasmodic manipulations
> > thereof.
>
> You're off on a tangent, rejecting normal English usage and making up
> terms of your own.

Not really.

> When I read the newspaper this morning the light
> has a physical effect on my retina which through a series of complex
> neural relays modulates the output of the motor neurons to my larynx,
> tongue and diaphragm producing sound waves relating to what I am
> reading.

You're inventing a connection where none exists. There is no neural
pathway for eye-voice coordination. You see through your eyes and you
speak through your voice. Both processes require that you are
conscious and voluntarily moving your eyes and larynx. That vocal
expression has a physical characteristic which we can observe
externally as motor neuron behaviors.

> If any component in this pathway, such as the optic nerve, is
> replaced with an artificial device that relays the electrical signals
> in a physiologically appropriate way do you claim that the downstream
> neurons would respond differently because the artificial nerve lacks
> the "sense" of the natural nerve?

It depends on the nature of the device and the nature of what it is
the device replaces. You could replace the retina and your visual
cortex will learn to use it. If you replace the visual cortex the rest
of your brain will be able to compensate functionally but you will be
blindsighted. If you have partial visual cortex replacement your brain
could adapt and learn to use it.

> If so, then you are claiming that
> neurons affect other neurons by something other than physical factors,
> going against not only all of neuroscience but also against all of
> science.

I forget what number I was on. I'll guess 6.

6. I have never claimed anything that goes against any neuroscientific
observation. I repeat again, if you think that I am claiming that,
then you do not understand what I am saying. My view is more
scientific because it accounts for all of the phenomena that are
involved and not just the ones that show up under a microscope.

>
> >> Cadrdiac myocytes in culture can synchronise their beating through
> >> direct contact. Artificial myocytes, if they were to replicate this
> >> behaviour, would have to be sensitive to the action potential of the
> >> natural myocytes.
>
> >> In general, any observable behaviour of the
> >> biological system that you want to replicate can be replicated by some
> >> technology.
>
> > Observable by what? If a cat replicated their owner, you would
> > probably have a very large and interesting smelling can opener.
>
> List any observable behaviour or property you want - it's up to you.

Ok. I'm a biological system. I observe that I sometimes have dreams
which foreshadow events in the near future. What technology would you
suggest replicates this?

> For an artificial neuron I think the timing of the action potential in
> response to environmental factors is the main thing to get right. I
> think the neuron's shape is important to take into account in this
> regard since the shape affects the electric field and excitability,
> but I don't think its mass is important. But I might be wrong: it
> could be that neurons sense their neighbours' tiny gravitational field
> and therefore the network with the artificial neuron would behave
> slightly erratically until this was taken into account. The
> engineering project would involve sorting this sort of thing out until
> eventually the artificial neuron would slot into the network with the
> level of tolerance that is acceptable for biological neurons.

If the neuron doesn't feel anything, then there is not going to be any
feeling at the higher processing level. These are living organisms.
They may not have a level of tolerance that is acceptable, just as
there is no substitute for water or carbon that is acceptable.

>
> >>Qualia are not observable
>
> > Qualia is the only thing that can ever be observed directly. It is
> > only through inference and reason that we can imagine a world outside
> > of that.
>
> Qualia are not observable directly by a third party (you knew this is
> what I meant).

Why does that matter though? If you connect your brain to theirs then
you could observe qualia directly, as some conjoined twins do. Why do
you privilege third party observability when dealing with a first
person phenomenology?

>
> >> and it is an open question
> >> whether they can be replicated, so we assume that they can't and
> >> consider the consequences. The consequences are that a person's qualia
> >> might change but, because the inputs to the motor neurons controlling
> >> speech are the same, he would declare that nothing has changed.
>
> > This is your fantasy, not mine. Since the 'inputs' to the motor
> > neurons have little to do with the mechanics which deliver the qualia
> > experiences and more to do with the sense that the person makes out of
> > the qualia, the speech is not controlled by anything but how the
> > person feels about their experience. You could control the speech
> > electronically - and make the larynx say what you want it to say, but
> > you can do that to a cadaver too - it proves nothing.
>
> What is the mechanism determining the timing of the motor neurons
> controlling the muscles of speech? Please don't say "the sense of the
> qualia": what *specifically* at the cellular level causes a particular
> motor neuron to fire?

The motor neurons each feel that it is time to fire, based upon a
collective feeling that the organism as a whole is attempting to say
something. What we think of as the charge and voltage across the cell
membrane is actually just the physical end of a larger phenomena which
includes sensorimotive phenomenology. The cell feels something, and
that feeling looks to us from a great distance like a contraction or
relaxation of pores, depolarization, action potential, etc. Just as
the circulation of traffic through a city would look to an alien
observer like regular patterns of circadian respiration among groups
of automotive cells.

>
>
> >> I keep repeating that there is no "pattern of neural firing" to
> >> replicate. Whether a biological neuron fires or not depends on its
> >> present state and its inputs. A neuron that would fire if the
> >> temperature is 37 degrees and the extracellular potassium
> >> concentration is 5 mM might not fire if the temperature is 39 degrees
> >> and the potassium concentration 6 mM.
>
> > It's true that you can control the firing of a neuron from the outside
> > - as you say, changing temperature, electrolyte or neurotransmitter
> > concentrations,  etc. That's medicine. But that isn't what is going on
> > right now as you and I type on our keyboards. We are driving the
> > behavior. Our intention alone is changing the instrument of the brain,
> > firing thousands of neurons at a time over many different regions -
> > not chain reactions, but parallel chords of simultaneous change
> > instantiated in a single high level firing pattern. You can see that
> > clearly in the MRI animations. You keep repeating something that is
> > factually incorrect and a misrepresentation of neurology.
>
> No, no, no. If neurons are coordinated in the spontaneous or even
> apparently purposeless activity they must have some physical influence
> on each other, generally thought to be synaptic connections, although
> there are speculations that the electric field may also be important.
> Physical influences are observable, understandable scientifically and
> computable. Henry Markram's group in Switzerland simulating rat cortex
> observed spontaneous gamma wave-like activity. This wasn't "programmed
> in", it was emergent behaviour given the basic computational model of
> the rat neuron when multiple such neurons were connected in a
> physiological way and the program run on a supercomputer.

The influence that they have on each other has a physical aspect, but
it has an experiential aspect as well. Sometimes the experiential side
drives the physical and sometimes it's the reverse. Computational
models can tell you about the physical aspect, and provide insight in
how to influence the behavior of neurons and therefore influence the
nature of the experience, but they can't tell you anything about the
experience itself and it's influence of intentionality the brain.

>
> >>The model of the neuron has to
> >> incorporate knowledge about how the neuron is affected by these
> >> variables, and this knowledge is obtained through research. But the
> >> model cannot predict what the temperature or the potassium
> >> concentration is going to be at a particular time, since neither can
> >> the biological neuron.
>
> > Your mistaking the unconscious change in variables associated with
> > conscious activity for the cause of conscious activity. All we know is
> > that the two phenomenologies are correlates. There is nothing to
> > support the idea that conscious activity does not also cause these
> > changes - quite the opposite. We can tell a person to think about
> > something in particular and have them light up a part of their brain
> > on an MRI. We can do that verbally and semantically - not by
> > introducing a chemical change into the brain directly.
>
> But there is a chain of events between telling a person to think of
> something and the fMRI changes. Even if at some point there is a
> triggering truly random quantum event there is a causal chain and the
> quantum event can be modelled probabilistically.

The chain of events has no beginning. It's arbitrary. Your view is
that everything that happens in the brain can be understood in purely
neurological terms. Telling a person something requires that the
patient understands what they said and voluntarily chooses to respond
by controlling their own low level neurological events. You
pathologically leave out that detail and try to imply that the high
level consciousness of the patient is an irrelevant epiphenomenon.

By always cherry picking the point at which your chain of causality
begins, you misdirect your attention to the consequences of the high
level decisions (the fMRI changes, quantum events, ion channel
depolarization) rather than the decisions themselves (telling a person
to think of something, the person choosing to comply, the person
thinking of something). The decisions have meaning to us regardless of
the mechanism, whereas the mechanism has no meaning whatsoever outside
of their relation to our signifying experience. This should be a clue.

Craig

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