Why a "magic bean" is necessary for consciousness -- except it's not magic, and it's not a bean
There are basically two camps on these threads -- which I'll call the informationalist camp and the physicalist camp.
The informationalists say that all which is needed for consciousness is for the brain to process information about the world around it. No further physical processes are necessary in the brain above and beyond those required to process information about what's coming in. In the case of dreams, that can be explained by retrieving such information from memory.
The physicalists maintain that this approach is insufficient, that the generation of conscious experience requires its own specialized hardware in addition to the hardware needed to "process information about" (not a physicalist term, but we'll borrow it) the "input" coming into the brain.
Some in the informationalist camp have derisively labeled this additional specialized hardware as -- for some reason -- a "magic bean". (Why they use the term "magic" rather than, say, "superfluous", I can't say.)
But the Achilles heel for the informationalist position is simply this -- if we take the simple example of performance of color in the human brain, for instance… color is not "information about" light.
As we've seen, color is not a property or quality of light, nor of the tissues in our brains.
Light does have distinct properties, of course -- speed, wavelength, frequency, amplitude… but none of these are qualia in our phenomenology, which is simply to say that we don't consciously experience any of that, for reasons that have been clearly explained upthread.
What we do experience is color, and brightness (meaning that quality that makes you squint from the glare). And neither of those are properties of either light or brain tissue.
Therefore, you can "process information about" light six ways to Sunday and you'll never get color. You'll never get red, because red is not "information about" light. It's not there to be "processed".
Trace the physics of the neural chain, and you'll never find red. It ain't there. (I'm ready to be proven wrong about this, of course, but I'll need a clear explanation of where the red comes from.)
In other words, the informationalists want something for nothing. So, in fact, it is they who are peddling "magic".
In the real world, you don't get something for nothing. If some new and unique behavior is being performed, then it's being performed by some sort of process involving matter and energy.
We can get a behavioral response to light from the bounce-back system. All you need are wires and chips and such. We can build machines that respond in different ways to different types of light, and in doing so these machines do indeed differentiate between light which our human brains respond to by performing different colors.
What you don't get from this system, is the performance or production of color itself.
There is no point in this chain reaction which we can point to and say, "This is where the red occurs".
Yet in our brains, red does occur.
But not all the time. We can run subliminal experiments in which we expose a human brain to a red square, for instance, in timeframes too brief for the brain to respond with any phenomenology at all -- in other words, the brain of the animal never has any conscious experience of seeing a red square.
And yet, if we do this repeatedly, and consistently follow the red square with a specific unrelated image, we find that the brain learns something from the process nonetheless -- so in later testing, for example, we can show the subject the previously subliminal images at consciously perceptible timeframes, and ask the subject to guess what image will come next, and we find that they do significantly better than random chance at the prediction task.
So in some cases, a human brain will perform red in response to having a certain type of light shone into the eye. In other cases it won't.
Now, some have said, well, the brain has "learned" to perform red. But if that's true, why hasn't my dog learned this trick?
No, that won't wash. In fact, performing red is a built-in function of the human brain -- or, at least, most human brains.
And since red isn't a property of light, the brain must be doing something above and beyond "processing information about" light in order to produce the red.
It is the contention of the physicalist camp that the production of red by the brain is not passive, and is not sufficiently or adequately explained by simply passing it off as "processing information about light" or retrieving such information from memory.
All real behavior requires some sort of hardware, and the performance or production of any sort of phenomenology is real behavior. It is behavior which produces something new and unique.
That's why a "rope brain" can't be conscious. Ropes can't perform red… or the smell of lemons… or the sensation of being sick. All of these are somehow actively produced by the brain, and their production is a behavior above and beyond the "bounce-back" system of the neural chain.
And because of the laws of physics, this extra work -- the production of the phenomenology -- must be performed by some sort of hardware. To label this hardware "magic" is not only wrong-headed but, I must say, rather childish.
All the physicalists are saying is that if you want to build a conscious machine, there must be some hardware dedicated to generating the phenogram, the phenomenology, behaviors like color and sound and pain and pleasure.
Merely "processing information about" the input won't cut it, because if it did, we'd always be experiencing some sort of phenomenology, even when dead asleep, but we know that this isn't the case.
The brain is doing something different, something additional, when consciousness cranks up. And in the real world, that "doing something" must be handled by some sort of hardware dedicated to the task.
That ain't magic. And it ain't beans.
Sorry. Carry on.
