If the movie 2001: A Space Odyssey taught us anything, it’s that computers know when we’re telling a lie. While that may not actually be the case for most computers in real life, it could be if they’re running a program created by scientists from the University at Buffalo. Building on a previous psychological study, the team produced software that allowed a computer to assess a speaker’s eye movements, to determine whether or not they were telling the truth in a prerecorded conversation. It turns out that the computer was able to correctly able to spot their lies with 82.5% accuracy. According to the researchers, a trained human interrogator only manages a success rate of about 65%. The project utilized 40 videotaped conversations culled from a pool of 132 used in the original psychological study, in which subjects chose whether or not to steal a cheque, and were then asked if they had done so.
The selected videos represented a variety of skin colors, head poses and lighting conditions, plus some of them included potential visual obstructions, such as eyeglasses worn by the speakers. In order for the computer to identify the tell-tale “lying eyes” of each person, it first needed a baseline example of their regular eye movements, as exhibited when they were telling the truth. This was accomplished by starting each interview with simple questions, that had obvious truthful answers, and observing the speakers’ eyes. In particular, the program took note of their rate of blinking, and the frequency at which they shifted their gaze. As the conversation moved on, the subjects were asked whether or not they had stolen the cheque. If their eye movement pattern remained the same, it was assumed they were telling the truth. If it changed, however, they were labelled as liars. While most of the speakers were caught out, a few were particularly good liars, and were able to keep their physiological responses (including their eye movements) under control. The scientists now plan on further studies utilizing a larger database, and ultimately hope to develop a system that could be used alongside human interrogators. “What we wanted to understand was whether there are signal changes emitted by people when they are lying, and can machines detect them?” stated assistant professor Ifeoma Nwogu. “The answer was yes, and yes.” (By Ben Coxworth from www.gizmag.com )
BUT ARE COMPUTERS BETTER THAN PEOPLE AT DETECTING WHEN PEOPLE LIE ?
Can computer software detect lies at a better rate than people? Scientific American reports that researchers at the University at Buffalo, The State University of New York claim that their software, which analyzes eye movement can determine a lie with 82.5% accuracy. Their work, which is as of yet unpublished, consisted of 40 interviews with subjects that were given a punishment/reward scenario. If they were to successfully lie and get away with it, they would be given a cash reward plus a group they support will be given a donation. If they were caught lying, a group they oppose were given money. Obviously, a 40 subject study is hardly a thorough study but they have bigger plans for their research. The researchers, who first presented their (still unpublished) results at the 2011 IEEE International Conference on Automatic Face and Gesture Recognition a year ago, believe they have laid the foundation for a more extensive study that will include a larger sample and take into account body language in addition to eye movement to determine whether new technologies can help interrogators in their search for the truth.
The study is based off of work of Paul Ekman, a Professor Emeritus psychology at the University of California, San Francisco, School of Medicine. Ekman studied emotions and their relation to facial expressions. The study’s co-author, Mark Frank, worked for Ekman U.C. San Francisco’s psychiatry department previously. Ekman’s focus on brief, involuntary facial expression is not without critics. One former FBI special agent finds a fundamental flaw with the Buffalo study: “One problem with this research is its overreliance on the face as the only place to evince information from the body,” says retired FBI counterintelligence special agent Joe Navarro, who spent 25 years with the bureau and was a founding member of its Behavioral Analysis Unit. “I can tell you as an investigator and somebody who’s studied this not just superficially but in depth, you have to observe the whole body; it can’t just be the face,” he says, adding that a failure to take body language into consideration could lead to “an inordinate amount of false positives.” In future work, the Buffalo researchers plan to take a more holistic view of behavioral cues.
“We know that the eyes give signals that lead to deception, but what about general body movements?” says Ifeoma Nwogu, study co-author and a research assistant professor in U.B.’s Center for Unified Biometrics and Sensors. Faster algorithms would also enable the software to flag behavioral deviations in near real-time, she adds. They also want to expand the sample size; the 40-person study is too small to be statistically significant. Dr. Ekman’s work and research is the basis of the plot for the television show “Lie to Me” which airs on Fox. He’s the first person to tell you that there is a (very large) difference between his research and the fiction on the TV show. Dr. Ekman’s website runs a blog that describes the facts behind the “Lie to Me” plots versus reality. CAVEAT: How the Lightman Group [fictional group from the television show] spots lies is largely based on findings from my research. Because it is a drama not a documentary, Dr. Lightman is not as tentative about interpreting behavior as I am. Lies are uncovered more quickly and with more certainty than it happens in reality. But most of what you see is based on scientific evidence.
Each show also provocatively raises the complex psychological and ethical issues involved in perpetrating and uncovering lies. In this weekly BLOG, I explain more about the science behind what you have been seeing and when the show takes poetic license. I took a small amount of time to review Dr. Ekman’s work. Obviously, I’m not a scientist and do not claim to be one (except at Halloween), but the research seems a little bare. A quick glance through the list of publications on his website showed mostly books and magazine articles. There are not many studies in scientific journals. One study I did see had a very small number of participants with a total of 28 subjects, (28 sets of twins so, 56 participants in total). I think it’s safe to say the jury is still out on the subject of telling lies from expression, way out. ( By Abourque )