Smile! It's You-Better-Be-Candid Camera

(CBS)  British scientists claim they have invented the world's most sophisticated lie detector.

It's called the "Silent Talker," reports CBS News Correspondent Steve Holt, and it's said to be over 80 percent accurate in ferreting out liars.

That's roughly comparable to the polygraph, but this system doesn't involve wiring subjects up. They just look into a camera connected to a laptop computer, while software analyzes thousands of tiny facial movements.

"These are quite small fleeting things that people can't usually spot," said developer Jim O'Shea of Manchester Metropolitan University, adding that the combinations of those movements can give a liar away.

The traditional polygraph monitors signs of stress such as perspiration, heart rate and voice pitch.

The assumption for both polygraphs and the Silent Talker is that lying triggers a sense of conflict and anxiety in the person being questioned. This leads to physiological change, for the polygraph, and facial movements, for the Silent Talker.

But skeptics say the machines only measure the fear of being caught.

The Manchester system took five years to develop.

"They interviewed the Yorkshire Ripper at least five times [before he was caught]," Dr Zuhair Bandar, the project director, told The Independent. "I am convinced that this is the kind of device which would have told them something was wrong."

The "Silent Talker" also delivers degrees of lying — complete lie and half-lie.

O'Shea claims trying to trick the machine just gives it more evidence to prove the subject is lying.