Computer spots micro clue to lies

Whether you are playing poker or haggling over a deal you might think that you can hide your true emotions. But telltale signs can reveal that you are concealing something, and now researchers at Oxford University and Oulu University are developing software that can recognise these 'micro-expressions' - which could be bad news for liars. 'Micro-expressions are very rapid facial expressions, lasting between a twenty-fifth and a third of a second, that reveal emotions people try to hide,' Tomas Pfister of Oxford University's Department of Engineering Science tells me. 'They can be used for lie detection and are actively used by trained officials at US airports to detect suspicious behaviour. 'For example, a terrorist trying to conceal a plan to commit suicide would very likely show a very short expression of intense anguish. Similarly, a business negotiator who has been proposed a suitable price for a big deal would likely show a happy micro-expression.' Tomas is leading efforts to create software that can automatically detect these micro-expressions - something he says is particularly attractive because humans are not very good at accurately spotting them. He explains that two characteristics of micro-expressions make them particularly challenging for a computer to recognise: Firstly, they are involuntary: 'How can we get human training data for our algorithm when the expressions are involuntary?' he comments.