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. 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. 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? 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. >> 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. 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. >>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). >> 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? >> 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 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. -- Stathis Papaioannou -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
