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Inventor’s machine can think for itself

Technically, Stephen Thaler has written more music than any composer in the world. He also invented the Oral-B CrossAction toothbrush and devices that search the Internet for messages from terrorists. He has discovered substances harder than diamonds, coined 1.5 million new English words, and trained robotic cockroaches. Technically.

By Tina Hesman
Knight Ridder News Service

http://www.sltrib.com/2004/Feb/02082004/business/136566.asp

Thaler, the president and chief executive of Imagination Engines in Maryland Heights, Mo., gets credit for all those things, but he is really just "the man behind the curtain," he said. The real inventor is a computer program called a Creativity Machine.

What Thaler has created is essentially "Thomas Edison in a box," said Rusty Miller, a government contractor at General Dynamics and one of Thaler’s chief cheerleaders.

"His first patent was for a Device for the Autonomous Generation of Useful Information," the official name of the Creativity Machine, Miller said. "His second patent was for the Self-Training Neural Network Object. Patent No. 2 was invented by Patent No. 1. Think about that. Patent No. 2 was invented by Patent No. 1!"

Supporters say the technology is the best simulation of what goes on in human brains, and the first truly thinking machine.

Others say it is something far more sinister — the beginning of "Terminator" technology, in which self-aware machines could take over the world.

The invention began to take shape in the 1980s. By day, the physicist worked at McDonnell Douglas Corp., where he wielded a powerful laser beam to crystallize diamonds. He built elegant computer simulations, called neural networks, to guide his experiments.

But at night, things were different. Shirley MacLaine and her ilk were all over the TV and on magazine covers talking about reincarnation and life after death and near-death experiences. It made Thaler wonder: "What would happen if I killed one of my neural networks?"

Neural networks can be either software programs or computers designed to model an object, process or set of data. Thaler reasoned that if a neural network were an accurate representation of a biological system, he could kill it and figure out what happens in the brain as it dies.

So after work, Thaler went home and created the epitome of a killer application — a computer program he called the Grim Reaper.

On Christmas Eve 1989, Thaler typed the lyrics to some of his favorite Christmas carols into a neural network. Once he had taught the network the songs, he unleashed the Grim Reaper. As the reaper slashed away connections, the network’s digital life began to flash before its eyes. The program randomly spit out perfectly remembered carols as the killer application severed the first connections. But as its wounds grew deeper, and the network faded toward black, it began to hallucinate.

The network wove its remaining strands of memory together, producing what someone else might interpret as damaged memories, but what Thaler recognized as new ideas. In its death spiral, the program dreamed up new carols, each created from shards of its shattered memories.

"Its last dying gasp was, ‘All men go to good earth in one eternal silent night,’ " Thaler said.

But it wasn’t the eloquence of the network’s last words that captured Thaler’s imagination. What excited him was how noisy and creative the process of dying was. It gave Thaler ideas. What if, he asked, I don’t cut the connections, but just perturb them a little?

Thaler built another neural network and trained it to recognize the structure of diamonds and some other super-hard materials. He also built a second network to monitor the first one’s activities.

Then he tickled a few of the network’s connections, and something began to happen.

The result was new ideas. The computer dreamed up new ultra-hard materials. Some of the materials are known to humans, but Thaler didn’t tell the network they existed. Other materials are entirely new, unknown to humans or computers before.

When Rusty Miller went to lunch one day in 1998, he picked up a specialized computer magazine called PCAI Journal. He flipped through the pages and came across a story about Thaler and his Creativity Machine inventing the ultra-hard substances. Instantly, Miller knew that Thaler had taken a step beyond other artificial intelligence technologies, such as fuzzy logic or genetic algorithms, he said.

The brilliance of Thaler’s invention is the noise he introduces into the system, Miller said.

"Noise allows neurons to have a little elbow room to dream up new ideas," Miller said.

Human brains are also noisy places, said Walter Freeman, a neurobiologist at the University of California at Berkeley. A debate has raged for half a century about what the brain does with noise.

Many biologists see noise as just a nuisance or a necessary evil, Freeman said. The brain devotes many neurons to the same task so it can swamp out that random activity, those scientists argue.

But Freeman subscribes to an alternative theory — that noise is essential for the brain to function properly. Noise provides variability that allows organisms to adapt to new situations, he said.

It’s not merely noise that makes Thaler’s Creativity Machines so ingenious, he argues. He has discovered a mathematical equivalent to the fleeting signals that work on neurons — a special kind of noise.

And Creativity Machines are their own best critics. In fact, they have critic networks built right in.

The critics select the best ideas generated by the noisy networks and reward good work. The feedback helps the network dream up even better ideas.

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