New polygraph measures body language
The Scotsman reports on a new lie detector system that works by measuring facial expressions. Claims of "80% accuracy" are meaningless; the technology is new, but otherwise this is no different to traditional polygraph. Both rely on the measurement of physiological responses, a subjective method that is reliant almost entirely on the judgement of the operator. Switching to a different physiological measurement doesn't change the fact that the assumptions are flawed.
Dubbed the "Silent Talker", the system detects and analyses thousands of tiny movements to determine whether people are being truthful or not. Following tests at Manchester Metropolitan University, researchers believe it is more accurate than standard polygraph tests used by the CIA in America. As it is also much simpler to use - needing just a camera, a laptop and no expert to operate it - they hope it could soon be seen in airports, police stations and even job interviews. [...] In tests carried out so far, the system has proved to be accurate in more than 80 per cent of cases - compared with a 70 per cent success rate for conventional lie detectors. - Scotsman, Picture of innocence reveals if you are lying.The use of visual processing for polygraph testing isn't new: Nature reported on a technique involving infra-red imaging a year ago.