Imagine if you could tell if someone was lying to you just by looking at them.

As this ScienCentral News video reports, a new technology can do just that, and it’s being developed to prevent terrorism.

Liar, Liar, Face on Fire

The Mayo Clinic’s James Levine is an expert on human metabolism and obesity, not anti-terrorism measures. And the thermal camera that he and scientists at Honeywell now report can detect lying was a tool for studies like the caloric expenditures of gum-chewing.

They’d been experimenting with the camera in measuring the effects of adrenaline and human responses to being startled, anxious or frightened, when they realized the camera could detect deception. When the system is calibrated to show hotter temperatures as brighter colors and colder temperatures as darker, the area around a liar’s eyes glows white-hot. "The signal really changes quite dramatically, there’s this whitening around the eyes that’s really very intense indeed, and it occurs the instant people start lying," Levine says.

The experiment now reported in the journal Nature was begun more than a year before September 11th. "To be frank, the reason this paper ended up in Nature was that after September 11th, the Honeywell group and myself were so moved that we contacted Nature and asked them to publish this data urgently," says Levine. "We realized that our research would have applications in this field."

Levine says it will take "tremendous effort" to test whether the system works as well in an airport as it does in the lab, but that in the best-case scenario, the cameras could be in use at airports in two years.

The experiment reported in Nature was designed the way mock crime studies have been used to test the time-consuming and invasive polygraph test. Twenty volunteer subjects were randomly assigned to either commit a pretend crime where they stole 20 dollars or to be innocent. All the subjects, regardless of whether they stole the 20 dollars or not, were told to say that they were innocent. The new thermal camera was then used to determine whether people were lying about stealing the 20 dollars or not. "The camera correctly detected 83 percent of the subjects who stole the money and those who were truly innocent," Levine says.

The same subjects were questioned using a polygraph conducted by experts at the Department of Defense Polygraph Institute. "What we found was that our camera… was just as accurate as the polygraph," says Levine, also pointing out that his camera sensor is much more practical for everyday use. "When one conducts a polygraph you need to have the subject attached to a whole series of measurements, there’s a cuff for blood pressure, there’s a breathing sensor, there’s a detector of skin resistance... and this requires the subject being seated, being carefully attached to a whole series of instruments and being very carefully monitored throughout the interrogation," he says. "The massive advantage of this technology if it proves to be truly useful in the field, is that all one needs to do is have a camera facing somebody’s face."

As for further comparisons to the much-debated polygraph, (see Elsewhere on the Web), that’s off the topic as Levine sees it. He hopes it will be useful as a screening tool only, and that it will be developed along with other new security technologies, including some in the works at Honeywell. "I think that this is going to be part of our armamentarium against the terrorists, but not all of it," he says.

But if the camera were widely available, couldn’t it be abused? "I think when one’s involved in the development of any new technology we can immediately see the potential benefits in terms of prevention of terrorist acts," Levine says, "but there are also ethical concerns too. For example, this kind of technology could easily be abused in the workplace," says Levine. "You could be sitting in front of your boss talking and think that you’re having a regular conversation, but during the entire conversation your boss is looking at a thermal imaging system under his desk and determining whether you’re lying to him or not. Could this kind of technology be used on a date, where one wants to determine whether the person you’re dating really does want to marry you? Could this kind of technology be used by the police when they stop you in the street? Could the technology be used in court? There are many potential ethical issues if this technology really proves to be as promising as our results suggest."

Levine has no ethical problems with mass-screening to improve the odds against another 9-11. "At this point in time there is such an enormous urgency to develop tools that could prevent terrorism that I think there is no question that we need to develop the technology further, and as rapidly as possible," he says.

Meanwhile, Levine the medical researcher wants to learn more about why our eyes heat up when we lie. "We’re all aware of the fact from our day-to-day communications, of when we’re talking to somebody and we think they’re lying," he says. "And what it is about that interaction that spots us off, no one knows. But one thing I put to you that I think is really quite intriguing, is that often when we’re interacting with people we’re looking into their eyes... and it’s those very subtle cues that we may be detecting when we’re talking to people who are lying to us, and this is in fact what this kind of technology may actually be detecting."