THE US Department of Defense has revealed plans to develop a lie detector that can be used without the subject knowing they are being assessed. The Remote Personnel Assessment (RPA) device will also be used to pinpoint fighters hiding in a combat zone, or even to spot signs of stress that might mark someone out as a terrorist or suicide bomber.
In a call for proposals on a DoD website, contractors are being given until 13 January to suggest ways to develop the RPA, which will use microwave or laser beams reflected off a subject鈥檚 skin to assess various physiological parameters without the need for wires or skin contacts. The device will train a beam on 鈥渕oving and non-cooperative subjects鈥�, the DoD proposal says, and use the reflected signal to calculate their pulse, respiration rate and changes in electrical conductance, known as the 鈥済alvanic skin response鈥�. 鈥淎ctive combatants will in general have heart, respiratory and galvanic skin responses that are outside the norm,鈥� the website says.
Because these parameters are the same as those assessed by a polygraph lie detector, the DoD claims the RPA will also indicate the subject鈥檚 psychological state: if they are agitated or stressed because they are lying, for example. So it will be used as a 鈥渞emote or concealed lie detector during prisoner interrogation鈥�.
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But finding ways to fulfil the DoD鈥檚 brief will pose a practical challenge, says Robert Prance, an electrical engineer at the University of Sussex, UK, who specialises in non-invasive sensors. 鈥淭hey might capture breathing rate with an infrared laser that senses chest vibration, but how they will measure a pulse through clothes, for instance, is a very big question.鈥�
鈥淭he device will be used as a concealed lie detector during interrogation鈥�
If the RPA is ever produced, it is likely to prove controversial. A remote lie detector would face even more difficulties than standard polygraph tests, which were themselves the subject of a damning 2003 report from the US National Academy of Sciences. 鈥淭here is no way a polygraph test can be carried out usefully without the subject knowing, because you actually want the person to worry about certain questions,鈥� says Bruce Burgess, an examiner with polygraph firm Distress Services of Leatherhead, Surrey, UK.
But Steve Wright, a conflict analyst at Leeds Metropolitan University, UK, raises the prospect of people identified as suspects by the device being captured and subjected to secret 鈥減risoner rendition鈥� as a result. And he warns that the RPA could introduce a 鈥渃hill factor鈥� into everyday life.
