> “Information”? Individual neurons can’t carry information any more than a single fiber of your Cat5 twister pairs can carry an http header. At best neurons are carrying data that eventually is made into information. Guess what is the bulk content of that data? Sensory data. And it is more a multi-directional protocol of information processing than mere transport of dead data.
When did I say individual neurons cary information? I said: "the interface is the set of synapses carrying information into and out of that region." A set of neurons surely can represent and process information.
> In sum, only thing we know is brain is involved in consciousness, it is a constituent of it, but we have no information as to what the exact list of constituents are, and research points in the direction of body being involved just as much.
Just as much? Really?
Stephen hawking certainly seemed to achieve a high level of consciousness, and his body didn't do much of anything.
> This was actually controlled for in the experiment with binding feet, and the effect was sustained.
I don't find this convincing. When I am sitting down and having a conversation, I am much more likely to be in the habit of using my hands than my feet, so it's going to be more distracting to take my hands away.
If hands are really involved in consciousness, you would have to show me a study where double amputees show cognitive impairment relative to control.
But to address your other points, let me restate my argument in a simple way:
1. Consciousness is one of the most complex phenomena we are aware of, which involves information processing and the unification of a lot of high-level functions we can locate in the brain, like language, decision making, emotion, value judgements and so on.
2. The 3lb lump of jelly in your head you call a brain is the most complex organ we are aware of, and we understand in a very detailed way how it is able to process information through chemical and physical processes.
3. Experimentally, we can induce profound and repeatable effects on consciousness through chemical and physical interventions on the brain.
4. Basically we know of no other way to have said profound and repeatable effects on consciousness besides intervening with the chemical or physical action of the brain. (I know you are going to argue with me on this, but you're going to have to show me more evidence than "mild cognitive impairment).
So we don't know know, but I think it's a fairly strong bet that the brain is responsible for consciousness. What other system can you point to which would be capable of the job?
To address the "brain in a vat" question, I would return to the car example you loved so much. If we put a car in a weightless vacuum (assuming we can still provide oxygen to the engine for combustion), when we step on the gas, the car is not going anywhere, but we still understand that capable of everything required to create forward motion under normal circumstances. By the same token, I would wager that a brain is capable of "doing consciousness" - whatever that physical process is - without inputs and outputs.
And we can see that. That's essentially what dreaming is. That's essentially what a heavy dose of LSD does.
And to give you a thought experiment: what if we could simulate all the inputs and outputs to our brain-in-a-vat perfectly? What if we wired up fake synapses that acted exactly like biological ones, but they were controlled by a computer instead of responding to reality. What do you expect would be the difference between that brain and the one in your head which would deny it consciousness as you experience?
And if you think it wouldn't be conscious because it lacks a body, let's go a different way. Let's say you start with a brain in a body, and then neuron by neuron, we replace all the organic inputs and outputs with an artificial one. We're already doing it with ocular implants and advanced prosthetics. When would you reach the threshold where this brain was no longer conscious?
It seems like you want me to explain the exact mechanisms for consciousness before you will be satisfied that it's located within the brain. I can't do that. Nobody can. But we can observe that the brain - even an incomplete brain - is necessary and sufficient to produce consciousness. We can observe that physiologically it's the most likely candidate. I would say the burden of proof is vary high to assert that we should look elsewhere.