By Joel Achenbach
Sunday, September 23, 2007
If I were to be eaten by a shark, I'm pretty sure the worst part would be not the pain or the mutilation or the actual dying and so forth, but rather the thought balloon over my head with the words, "I'm being eaten by a [expletive] shark!"
Whereas a fish doesn't have this problem. A fish has no thought balloon, or just a teensy little one, with a monosyllabic fish-word like "Urp!" A fish probably suffers, but it doesn't have the additional suffering that comes from knowing that it's suffering, and from regretting that it went swimming instead of watching the golf tournament, and from hearing, as we all do whenever we're devoured by sharks, the theme music from "Jaws." You know: that tuba.
All of which is a deft way of introducing our subject today: The Mystery of Consciousness. It's one of the biggest unknowns, right up there with the origin of life. But it's under a multi-pronged assault by scientists, who vow to crack the code of the mind in the same way that they are deciphering the human genome. It's all very exciting, with the one catch that no one can really agree on what the mind is.
"With consciousness, there is no agreement on anything," says Giulio Tononi, a professor of psychiatry at the University of Wisconsin at Madison, "except it's very difficult."
Jim Olds, who directs George Mason University's Krasnow Institute, a think tank devoted to the study of the mind, says of his field, "We're waiting for our Einstein."
The human brain is a hunk of meat that weighs about three pounds. It contains about 30 billion cells, called neurons. The networking of these cells involves 100 trillion meeting points, or synapses. This is the most complex object in the known universe (though if we explore the stars we may eventually find organisms with brains that make ours seem as impressive as Twinkies).
Human brains can do things that no computer can match. Sure, a computer can beat a human at chess, but only with brute-force calculation of every conceivable move. The most sophisticated robots still lack the basic smarts of a 2-year-old, who can perceive the world in three dimensions and go searching for a kitty cat while somehow avoiding the jutting edge of the coffee table. Negotiating the world requires massive bandwidth.
"The engineering problems that we humans solve as we see and walk and plan and make it through the day are far more challenging than landing on the moon or sequencing the human genome," psychologist Steven Pinker writes in his book "How the Mind Works."
Beyond the basics of perception and motor skills, the human brain has a premium feature: consciousness. You could also call it sentience, or self-awareness, or just the thing that makes it such a drag to be devoured by a mindless oceanic carnivore. This is what keeps us from being zombies. We perceive ourselves as actors on the stage of life. We sense that there's an "I" somewhere inside our skull.
"Consciousness is a big thing," Tononi says. "It is the single biggest thing of all. It is the only thing we really care about in the end."
But we don't understand it. We don't know how, in the words of philosopher Colin McGinn, "the water of the physical brain is turned into the wine of consciousness."
Will we ever know?
Earlier this year, Jim Olds gathered a bunch of big thinkers at George Mason University for a two-day conference on the mind. He and his allies want the federal government to invest $4 billion in an initiative that would be called the "Decade of the Mind." This would be a follow-up to a 1990s program called the "Decade of the Brain," which brought increased attention to neuroscience. The new initiative would be an attempt to take science into a realm previously explored only by philosophers, theologians and mountaintop yogis.
"Brain science is an exhaustive collection of facts without a theory," Olds says. "This is for the nation as a whole to invest in one of the fundamental intellectual questions of what it is to be a human being."
In a letter published a few weeks ago in the journal Science, 10 scientists said that a Decade of the Mind would help us understand mental disorders that affect 50 million Americans and cost more than $400 billion a year. It might also aid in the development of intelligent machines and new computing techniques. A breakthrough in mind research, the scientists wrote, could have "broad and dramatic impacts on the economy, national security, and our social well-being."
There's reason to be optimistic. Look at what has happened in recent years with the development of brain scans, such as MRIs, that let us observe the brain at work in real time. As the technology improves, the brain becomes more transparent, less of a black box.
That said, the mind isn't something that pops up on a computer screen. People have been poking around the brain in search of the mind for many centuries, and no one is even sure what neurological structures are the most critical to generating consciousness. Descartes, who gave us the most famous line in the annals of philosophy ("Cogito, ergo sum" -- I think, therefore I am), believed the center of consciousness to be the pea-size structure known as the pineal gland. Nice stab, but it turns out that the pineal gland does not seem to have much to do with creating the "I" in our head.
Other brain structures are important, such as something called Brodmann area 46, and the anterior cingulate sulcus, and the thalamus, and of course the knurled, dipsy-doodle structure called the cerebral cortex. We can also be confident that consciousness does not depend on the cerebellum, which is 50 billion neurons worth of brain matter that you could surgically remove without "losing your mind." As Tononi puts it, you could toss the cerebellum in the garbage and " you would still be there."
The classic idea of "dualism" solves the location problem by defining it away: The mind is perceived as separate from the body, something that can't be reduced to machinery. It's unreachable by the tools of the laboratory. Dualism flatters us, for it suggests that our minds, our selves, are not merely the result of rambunctious chemistry, and we are thus free to talk about souls and spirits and essences that are unfettered by the physical body.
Dualism is pretty much dead to serious researchers, though an echo of it can be found among philosophers who are sometimes called the Mysterians. The philosopher David Chalmers has famously made a distinction between the Easy Problems, which involve the ways that the brain creates specific elements of consciousness (vision, language, memory, attention, emotion, etc.), and the Hard Problem, which is the mystery of how all the elements come together in that powerful sense of self (" I am Spartacus").
But here's the most radical idea of all: The reason why the mind is hard to define is not because it has some mysterious, ethereal, spooky qualities but because it doesn't really exist. We just imagine it. You might say it's all in our heads.
When you see a Toyota cruising down the street, you know that you're looking at a complex machine with many parts. You also know that there's a person inside, some intelligent being who's directing the Toyota's movements. The human brain is another complex machine with many parts -- but it doesn't seem to have a driver most of the time.
The brain operates day and night and performs myriad functions of which we have no direct awareness. Even our "conscious" brain is actually many different operating systems. It's as though the Toyota is being driven by hundreds of tiny elves, with no single elf in charge.
This is the view espoused by the philosopher Daniel Dennett, author of "Consciousness Explained," who argues that the notion of a central executive in the brain is an illusion. "It's a mistake to look for the president in the Oval Office of the brain," he declares.
It's bad enough that astronomers tell us that the Earth isn't at the center of the cosmos; it's worse that biologists tell us we're all descended from pond scum. Now we have philosophers saying that the self is illusory. You are not really there.
The mind might be what Pinker calls the "ultimate tease." He has written that "the most undeniable thing there is, our own awareness, would be forever beyond our conceptual grasp."
The mind, in this view, isn't a single, specific thing. It's more like a process, or an "emergent" phenomenon. This means that the many disparate components are not themselves conscious, but when they get together, the consciousness precipitates into being. Grabbing hold of the mind, however, would be like trying to seize a puffy white cumulus cloud.
Cracking the code of the mind may be ultimately impossible. My guess is that a century from now, consciousness will still make the list of Biggest Mysteries and scientists and philosophers will still be arguing about the what, where and how of it all.
But we should still take a whack at it. Ten years and $4 billion: That's a reasonable cost. The evolution of the human mind is arguably the most important biological event in the history of our planet since the origin of life itself.
We should try to understand how the brain makes the mind. And then we can make up our minds about what to do with ourselves.
Joel Achenbach is a Washington Post
staff writer and blogs at washingtonpost.com/