Aug 19, 2002 (The Dallas Morning News - Knight Ridder/Tribune News Service via COMTEX) -- Changing your mind is a lot easier than changing your brain.
But it's not so easy to explain why that should be. Mind and brain are supposed to be hard to separate from each other. The mind, you'd think, is merely the brain in action, reflecting the brain's thoughts and articulating the brain's decisions for guiding the body's behavior.
Still, it seems, the mind doesn't merely reflect the brain's electrochemistry. Sometimes the mind tells the brain what to do, rather than vice versa. The mind can order the brain to think about politics rather than baseball, or working instead of eating. The mind can tell your brain to make your arms and legs move, and even can countermand the brain's initial instinct to do something that the mind realizes will probably cause trouble.
Such abilities of the mind are what consciousness and free will are all about.
Of course, there are schools of thought teaching that free will is an illusion, and that consciousness is just a figment of human imagination; it's a word masking ignorance about how the brain works. But the real ignorance might be in denying a scientific way for the whole brain to influence its parts.
Nobody seriously doubts, after all, that a whole brain has abilities far beyond those of any of its individual nerve cells. It's an exquisite example of what scientists call "emergence," the appearance of new properties when you put enough pieces together.
Emergence is the fancy term for the familiar adage about the whole being more than the sum of its parts. As usually expressed, it proclaims that the cooperation of little pieces can produce novel phenomena. But just as the pieces can contribute to new properties of the whole, the existence of the whole can change the properties of the pieces. And something like that may be just what's going on with the mind and the brain, an idea that has been explored by Evan Thompson, of York University in Ontario, Canada, and the late Francisco Varela of Pitie-Salpetriere hospital in Paris.
"Emergent processes correspond to the collective behavior of large ensembles," they wrote last year in a commentary in Trends in Cognitive Sciences. But once the members of an ensemble link to generate new collective behavior, they can no longer do all the things they did on their own. Like a versatile musician - a "one-man-band" - who joins the orchestra and must then play only one instrument, parts of an ensemble "no longer have the same behavioral alternatives open to them as would be the case if they were not ... linked in the system," noted Thompson, of the philosophy department, and Varela, who was a cognitive neuroscientist.
So the whole is not only more than the sum of its parts, the whole can exercise some control over its parts.
"If conscious cognitive acts are emergent phenomena, then accordingly we can hypothesize that they have causal effects on local neuronal activity," Drs. Thompson and Varela wrote.
It's not such a bizarre idea. It merely acknowledges that what the brain is doing can affect how its parts are working - some top-down control rather than all effects caused exclusively from the bottom up. Or mind over brain. Way back in the 1950s, a famous experiment showed that doing a math problem mentally can block nerve cell activity that would have caused an epileptic seizure. The mind's high-level activity constrained the physical actions of the brain's "low-level" nerve cells (or neurons).
And so it makes a certain amount of sense to conclude that the mind is not merely the output of neurons computing, but a manifestation of the whole brain directing activity in some of the brain's parts.
There's a further implication of this line of reasoning. No nerve cell is an island. If the mind emerges from many neurons getting connected, the mind must in some way reflect everything else that the neurons are connected to. Most obviously, neurons are connected to the rest of the person's body. But the body is not isolated from the rest of the physical and social world. The mind emerges from the ensemble not only of neurons, but also of neurons, body and environment.
"Because they are so thoroughly enmeshed - biologically, ecologically and socially - a better conception of brain, body and environment would be as mutually embedded systems rather than as internally and externally located with respect to one another," Drs. Thompson and Varela declared. "We ... suggest that the processes crucial for consciousness cut across the brain-body-world divisions, rather than being limited to neural events in the head."
These ideas contain a heavy dose of serious speculation, but they identify a way of looking at brain-mind issues that just might illuminate them a little better than usual.
At least this approach offers a good reason to dismiss the critics who contend that consciousness is just a figment of the imagination. After all, even if consciousness is a figment of the imagination, you'd then need to explain what imagination is.
(Tom Siegfried is science editor for The Dallas Morning News. Readers may write to him at The Dallas Morning News, Communications Center, Dallas, Texas 75265.)
(C) 2002 The Dallas Morning News