Live from Austin!

A month ago, I wrote about myself and other myths–some interesting scientific results from research into the nature of consciousness. I missed a couple, however.

For many years, scientists have studied the nature of sleep, and of dreams. These studies have started to overlap with those looking at the nature of consciousness. One experiment involves stimulating the brain using transcranial magnetic stimulation or TMS, and watching the outcome on an FMRI scanner as the patient is gradually anesthetized or allowed to fall asleep.

In the conscious, self-aware mind, TMS results in patterns of excitation that range over large areas of the brain. This kind of non-localized excitation is now being used to prove that coma victims are not brain-dead; they are asked to visualize playing a game of tennis, which produces an easily measurable and distinct excitation pattern in FMRI scans.

So similarly, TMS excitation of a conscious mind produces a clearly distributed pattern of neural firing. In a non-conscious mind, the excitation is highly localized and remains wherever the stimulation occurs. In a dreaming mind, the excitation stimulates adjacent areas, but doesn’t range as far as in the conscious mind.

So in effect, the difference between being alive and being in a coma is like the difference between a lab full of disconnected computers, and a lab full of computers connected via a network. Dreaming is like a degraded network where the signals are rerouted to nearby systems instead of their proper destination.

What struck me as shocking is this: When you’re in deep sleep, not dreaming, the network is down–exactly like when you’re in a coma, or have just died. The difference between being awake and being in non-dreaming sleep is a difference of kind, not of degree. Awake versus dreaming, on the other hand, that’s a mere difference of degree. And non-dreaming sleep versus coma–well, that’s a difference so subtle that we don’t really understand it, and it seems to have nothing to do with thought patterns.

In other words: My conscious self-awareness, the mythical “myself”, literally ceases to exist every night, just as much as it would if I actually died. There is no “me” until I start dreaming, at which point self-awareness re-emerges partially as the network comes back online. The fact that I’m a lucid dreamer is probably just my network activating more than average.

As the ancient Greeks put it, “sleep and death are brothers”. The Bible uses sleep as a metaphor for death. Now science is starting to discover that our ancient intuitive guesses about the nature of sleep and of death are pretty close to the truth.

I had always assumed that what made me me was some sort of continuity of mental process; that when I went to sleep, the activities that are me continued–just at a lower level, beneath my conscious awareness. It now looks as if this is completely wrong. But if there’s no continuity of thought process between me and the consciousness that will be animating this body tomorrow morning, then in what sense is that person actually me? He’ll have my body, and my memories, but surely that isn’t enough?

I’m only beginning to adjust my worldview to this new knowledge. The odd thing is, rather than keeping me awake at night, it’s almost comforting. If I’ve died over 10,000 times already, the thought of dying one last time seems like much less of a big deal.

Scientific American recently published a special edition titled The Hidden Mind. While a few of the articles were disappointing, the magazine finished with a true gem written by David J. Chalmers. It attempts to address the difficult problem of consciousness; not the problem of how to achieve it on a Monday morning, but the even tougher problem of how to explain it. It’s titled The Puzzle of Conscious Experience, and I recommend that you go read it.

One of the things I’ve often wondered about is why we are conscious and self-aware. I say “we” because I assume other people are conscious too, based on their observed behavior. Cats also behave as if they have consciousness and self-awareness; it’s pretty clear that they have pride, which to me requires that they have some concept of self-image.

Looking at living creatures, it seems pretty clear to me that there’s a spectrum of consciousness. At one end, you have organisms like yeast and ants, which basically behave like blobs of chemicals or little automata. Further along the scale you find birds, mice, and other animals that rely largely on instinct. Then you reach the otters, cats, dogs, and other creatures that appear to experience emotions, solve complex problems, play with things for fun, and communicate with each other.

The most likely hypothesis to my mind is that consciousness is some kind of emergent property of brains of sufficient complexity, which are structured in an appropriate way. Could a machine become conscious? I see no reason why not, though it might require a machine very unlike a regular computer.

All this gets me no closer to being able to say what consciousness is, though. I can’t explain it in terms of electric fields in a network, or quantum patterns of electrons in the brain, and nobody else seems to be able to either.

Chalmers proposes a radical hypothesis: What if consciousness is actually a fundamental feature of the universe, like gravity or electromagnetism? What if it isn’t reducible to other things?

I’ve been pondering this idea, and I think it makes a lot of sense. For starters, it offers a neat way to sidestep the awkward question of what an observer is in the Copenhagen interpretation of quantum mechanics. Perhaps an observer is simply a sufficient quantity or density of consciousness that has become entangled with the quantum events in question. Maybe physicists will one day be able to come up with equations specifying exactly how much consciousness it takes to collapse the wave function.

To go back to consciousness-as-emergent-property, perhaps consciousness is a kind of stuff that arises when certain kinds of information processing neural networks get sufficiently complex—just like gravitational fields arise when enough particles with mass group together in physical space.

Chalmers points out that the idea of consciousness as a fundamental property is very compatible with some of the recent theories from people like John A. Wheeler and Stephen Wolfram, who have suggested that perhaps information is fundamental to the physics of the universe.

There’s still another reason why I like Wheeler’s proposal, and it’s even less politically correct (from a scientific point of view) than Stephen Wolfram’s ego. See, it seems to me that consciousness being a fundamental property of the universe is remarkably compatible with Buddhist (and, for that matter, Hindu) cosmology.

Buddhism and Hinduism talk of a universal‘field’ of consciousness which pervades all things. Our individual consciousnesses are described as being like waves on an ocean. When we die, the waves collapse, and new waves are formed. (A common misconception is that Buddhism believes in reincarnation of the Shirley McLaine sort, where the intact soul travels from body to body.) I thought about waves of consciousness coalescing around complex neural networks, and it suddenly struck me how much the whole thing sounded like the Higgs field, and gravitational forces arising near massive objects.

Can I prove any of this? Of course not. But it’s the best working hypothesis I’ve got so far.