CIA faces up to a better lie detector

Two US research teams developing software that can recognise and analyse facial expressions have caught the attention of the US Central Intelligence Agency (CIA), as a potential tool to build a better lie detector.

Professor Terry Sejnowski, who leads one of the research teams in the Computational Neurobiology Laboratory at the Salk Institute for Biological Studies in California, calls the new facial technology an "emotion detector".

"It could be used in conjunction with a polygraph or more casually, for example, a camera hidden in the corner of a room. It distinguishes finer gradations of emotional response - whether the person is truly happy, sad or angry."

Professor Sejnowski's work coincides with that of Professor Jeffrey Cohn of the University of Pittsburgh and Carnegie Mellon University.

Cohn's work is based on the coding system known as the Facial Action Coding System (FACS) developed in the 1970s. It defines the movements of each of the 44 muscles in the human face, information used by experts to study frames of video images and "read" people's expressions.

"Our Automated Face Analysis system studies wrinkles and furrows, as well as other features, to quantify subtle changes in facial motion, rather than focusing on prototypic expressions," explains Professor Cohn.

The CIA, intrigued by both sets of research, has now funded a collaborative effort between the two teams, using the same set of data to compare their results.

"The CIA is interested in the impact of this technology," said Professor Sejnowski.

"We will deliver the comparison study sometime this fall, but it's going to take several years and a significant financial investment before we have a marketable product."

Current lie detectors, such as the polygraph, are used by several companies for security clearances and sometimes by the police, though the results are not normally admissible in US courts.

They measure perspiration, breathing and heart-beat rates while the subject is being questioned, but critics claim that the same physical reactions can be caused by a number of different emotions, like anger or pain, and consequently are unreliable indicators.