You can't hide those lyin' eyes

By KATHERINE HOBY and STEVE CONNOR

A high-definition heat-detection camera that can detect the blushes of expert fibbers is exciting aviation security experts.

Scientists have developed a thermal-imaging camera that can pick up minute changes in heat given off by a rush of blood to the skin around the eyes when a person lies.

They found test volunteers got hot around the eyes when lying, but stayed cold when telling the truth.

Many "good liars" are often unable to suppress blushing around the eye sockets - a phenomenon exploited by the inventors of the camera, which detects temperature change of just 0.025 degrees.

In a study published in the journal Nature, the scientists say the camera is quicker than a polygraph, can be used by non-experts and has the added advantage of not requiring someone to be wired up to the device while being interviewed.

"Were this thermal signature to accompany lying, it could be used for instantaneous lie detection without the subject even being aware of the test," said inventors Dr James Levine and Dr Ioannis Pavlidis.

Traditional lie detectors are impractical for mass screening. They are time-consuming and the results must be interpreted by operators whose judgment is often subjective.

But the new video technique merely compares the flow of heat with the skin before and after a question is asked and identifies a potential liar when the difference is significant.

To test their idea, the inventors recruited 20 volunteers, eight of whom were asked to stab a mannequin and "rob" it of $20.

Each person was then interviewed and asked: did you steal the $20? The camera correctly identified six of the eight liars - a success rate of 83 per cent - and 90 per cent of the innocent individuals.

The Pentagon has asked scientists how their invention could be used for routine airline security checks.