What Makes Up My Mind?

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?

CONTINUED     1           >

© 2007 The Washington Post Company