In laboratories and hospitals around the world scientists are changing the way we think - about how we think.
Twentieth century technology has made it possible to peer inside the human brain and study it in more detail than ever before.
"There may come a day when we say 'Well, here's how the brain learns. Why don't we try to be as efficient to matching that natural process as possible?'" Mazziotta says.
Mazziotta and his group can watch as the brain works. Inside a magnetic imaging machine, one member of his team is taking a memory test. A computer image shows which parts of the brain are working to remember faces and names.
Despite all the brainpower in the medical world, the brain has been one of the most mysterious parts of the body. But that's about to change. Computer scientists now believe they'll be able to re-create the power of a human brain soon.
"We'll have the basic hardware - the 20 million billion calculations per second of the human brain - in about 20 years," says Ray Kurzweil, computer scientist and inventor.
Kurzweil is very matter-of-fact about things that sound like matters of fiction. He has built machines that understand speech and that learn foreign languages. And he has built machines that create art.
By the year 2050, computers will be small enough and smart enough to work with people from inside the human brain, Kurzweil believes.
"We'll be able to send intelligent machines that are the size of blood cells.Â…I call them nanobotsÂ…nanorobots...through our bloodstream. They'll take up positions in our brains," says Kurzweil.
"And they'll actually expand the human brain. They'll add more memory, more cognitive capability," he adds.
Don't laugh. Work has already begun on cell-size computers.
At the University of Southern California, Theodore Berger has shown that brain cells called neurons can grow onto microchips and communicate with them.
"The capability exists for building computer chips that act just like nerve cells, and we're developing the capability for interfacing those computer chips with the brain," says Berger.
Electronic implants are already used to help patients with brain damage perform simple tasks on a computer. But Kurzweil sees a day when microscopic computers will make all kinds of learning as easy as dwnloading.
"When the technology goes in our brains, we could actually provide skill and insight to create art and music, literary, visual arts that we couldn't otherwise create," says Kurzweil.
Ultimately humans may be able to download information onto one of these chips and give someone instant knowledge, he says.
As they explore more of the brain, scientists are starting to believe that it's not much more than a huge number of electrical circuits. Now the question is: Can humans re-create everything created by those circuits?
Berger says his guess is that we'll be able to re-create everything - fear, loathing, love, hate, sex appeal and even a sense of humor - on a microchip.
It's not a very romantic notion of the future. But there are scientists who believe that when the line between people and computers is blurred in the 21st century, both humans and machines will be better off.
Click here for more information on the University of Southern California Human Brain Project.
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