Piggy, I tried PM'ing you but it appears your inbox is full, so I'll ask on here. If you don't mind me asking, what is your position/view, I take it your a materialist?
I'm not any kind of -ist, acutally, but if it help others to group things that way, that's fine.
When I look around, I see energy and mass. I don't see even the slightest reason to believe that souls, gods, and such are real. And since they explain nothing and create new problems if we propose them, I don't bother considering them.
Anyway, based on experimentation on the brain, we can be sure at this point that consciousness is something the brain does. (We actually need a verb for it, not a noun -- that pesky noun creates serious problems in how people tend to think about awareness.)
So the question is: What is the brain doing?
There is a camp which contends that consciousness can be explained entirely by information processing (with only enough hardware to support the "running of the program" so to speak). In other words, conscious awareness arises through the same sort of process by which a computer calculates the sum of 2 and 2, not by the same sort of process by which it plays a CD (which requires additional hardware dedicated to that purpose which is not strictly info-processing, such as spinning the disc and deploying the laser).
Pixy Misa, Rocket Dodger, and drkitten are -- iinm -- in this camp.
The background to this view goes something like this:
A great big chunk of what the brain does can be done by a
Turing machine. And if we look at how neurons work, we can model what they do with a Turing machine. (Which doesn't mean that the Turing machine can produce a simulation of it, but rather that it can actually do the same thing.)
Since the brain is made of neurons, everything the brain does can be done by a Turing machine, which means -- for all intents and purposes -- that the brain
is a kind of Turing machine.
The necessary corollary to this is that a properly designed Turing machine can do everything that a brain can do, which means that a properly designed Turing machine can be conscious.
Sounds pretty good, right?
But there's actually an implicit leap of faith buried in there, and that is this: That conscious awareness is the same kind of activity as those other activities of the brain that we know TMs can accomplish, and that it requires nothing more than neural activity.
However, if doing consciousness is not the self-same kind of activity as, say, adding numbers, and if it does require something over and above classical chain-reaction neural activity, then the theory falls apart.
And as it turns out, there's evidence that the latter is true.
Let's take a look at the first point: Conscious awareness is no different from other types of brain processes.
On the surface, we can see that this is highly likely to be false, because conscious awareness is so strikingly different from everything else the brain is doing. Qualitatively different.
In fact, being conscious is a physical phenomenon. It's something happening in the real world. It does not really bear any resemblance at all to information processing.
And through experimentation we now know that the brain can do all kinds of things (including perceiving the world and acting on those perceptions, even learning through experience) whether we are conscious of those things happening or not.
So consciousness awareness appears to be distinct from, but entangled with, the strict info-processing underlying it.
But what about the neuron argument? If the brain does everything through the firing of neurons, and that alone, then don't we have to accept that it's a Turing machine, and therefore IP alone must explain everything it does?
As it turns out, no.
Last year, a study was published which I cited upthread that offers us unprecedented insight into what the brain's doing when it does consciousness.
A new paper suggests that four specific, separate processes combine as a "signature" of conscious activity. By studying the neural activity of people who are presented with two different types of stimuli – one which could be perceived consciously, and one which could not – Dr. Gaillard of INSERM and colleagues, show that these four processes occur only in the former, conscious perception task.
This new work addresses the neural correlates of consciousness at an unprecedented resolution, using intra-cerebral electrophysiological recordings of neural activity. These challenging experiments were possible because patients with epilepsy who were already undergoing medical procedures requiring implantation of recording electrodes agreed to participate in the study. The authors presented them with visually masked and unmasked printed words, then measured the changes in their brain activity and the level of awareness of seeing the words. This method offers a unique opportunity to measure neural correlates of conscious access with optimal spatial and temporal resolutions. When comparing neural activity elicited by masked and unmasked words, they could isolate four converging and complementary electrophysiological markers characterizing conscious access 300 ms after word perception.
All of these measures may provide distinct glimpses into the same distributed state of long-distance reverberation. Indeed, it seems to be the convergence of these measures in a late time window (after 300 ms), rather than the mere presence of any single one of them, which best characterizes conscious trials. "The present work suggests that, rather than hoping for a putative unique marker – the neural correlate of consciousness – a more mature view of conscious processing should consider that it relates to a brain-scale distributed pattern of coherent brain activation," explained neuroscientist Lionel Naccache, one of the authors of the paper.
Now, is that something which Turing machines can do?
If I understand TMs correctly, I believe the answer is "No". I don't see a capacity for a "distributed pattern of coherent activation" / "distributed state of long-distance reverberation" in a TM. Perhaps I'm wrong, but if so, I'd be interested in hearing how that would work.
In any case, we must be open to the possibility that classical chain-reaction neuronal activity is not the whole story for the brain, especially when it comes to consciousness because (despite Pixy's claims to the contrary) we do not yet understand how the brain does it.
Not only that, but nobody has ever produced any model or even any hypothesis of how IP could possibly, by itself with just enough hardware to handle the IP, generate a physical phenomenon like conscious awareness. It's a bit like saying that IP alone can generate light.
So it turns out that all these claims about info-processing alone being the cause of conscious awareness rest on a leap of faith which we have good reason to be highly skeptical of.
Despite what that camp will try to tell you, there is no info-processing model of consciousness specifically, and there is no experimental or observational evidence supporting the claim that IP by itself is somehow responsible for this phenomenon.
