OAK RIDGE, TENN. Lie-detector alternative uses facial temperature
The capillaries constrict when a person tells a lie, lowering skin temperature.
The detection of deception.
A little-known research group in Oak Ridge, Tenn., is developing an alternative to polygraphs, using subtle temperature changes on a person's face to tell if he or she is lying. Early results are promising.
Jerry Eisele, director of the Center for Human Reliability Studies, said the U.S. intelligence community funded the feasibility project, but he declined to be more specific.
The Oak Ridge team tested the technique -- infrared thermography -- on 40 volunteer participants. In a carefully controlled test setting, participants were asked to take one of several objects from a crime scene and then try to conceal that information from questioners. An armed police officer was stationed in the room to make the interrogation more realistic.
Researchers used an infrared camera capable of detecting temperature changes of fifteen-one thousandths of a degree. Taking 10 or more picture frames per second, they evaluated slight changes taking place on a person's face -- particularly around the nose, the most responsive area.
The team correctly identified the item in a subject's possession in about four of five cases. In about 40 percent of the cases, the evidence was very strong. The success rate compares favorably with polygraph tests, officials said.
"The polygraph has been around for like 67 years and is the culmination of developments [and] research over that time," said Don Watkins, coordinator of the Oak Ridge project. "We've achieved similar results to the polygraph in two or three years. That is a significant achievement, and I think we can just get better."
The Center for Human Reliability Studies is part of the Oak Ridge Institute for Science and Education, a U.S. Department of Energy facility.
For the thermography project, the center worked with Oak Ridge National Laboratory, drawing upon ORNL's expertise in digital imaging, software development and statistical analysis. The research team also included two polygraph specialists, a plastic surgeon and a psychologist.
The polygraph relies on equipment to monitor blood pressure, pulse, respiration and galvanic skin response while a subject answers questions.
Like the polygraph, infrared thermography monitors physiological changes that might be tied to a subject's stress from deception. However, unlike the polygraph, the technology does not require wires and cuffs and other monitors that might add to the stress level.
Polygraph exams are widely used and widely controversial, and the U.S. government is interested in developing alternatives. That was one of the recommendations of a report last year by the National Research Council, which reviewed the scientific validity of polygraphs.
The premise for using infrared thermography is that the human body's response to deception will leave telltale signs that are detectable in thermal images of the face. It's anticipated skin temperature will drop as blood capillaries restrict as part of the nervous system's response.
"The heat from the core of your body cannot get to the skin as fast as it normally will, so your skin should cool when you start to tell a lie," said Ralph Dinwiddie, a senior research scientist at ORNL's High Temperature Materials Laboratory.
Watkins said researchers looked at several areas of the face, primarily the forehead, cheeks, nose, around the mouth and the sides of the neck.
The team did two studies. The first effort focused on the technology itself and how it picked up changes in face temperature. The second was to evaluate responses among humans in deceptive situations. Researchers solicited volunteers by posting notices at local institutions.
The Oak Ridge team has submitted proposals to a number of federal agencies to conduct follow-up research and develop the necessary software and data-analysis systems. The technology also would be tested on a larger scale under more diverse conditions.