Brain scan lie detectors ‘may already be in use’

A brain imaging technique called fMRI may be being used as a “lie detector” by US intelligence agencies, despite concerns over unreliability and the possibility of abuse, a leading academic has claimed.

Professor Jonathan Marks, a bioethicist at Pennsylvania State University in the US and a lawyer at London’s Matrix Chambers, says in an article in the American Journal of Law and Medicine that he believes that the use of functional magnetic resonance imaging (fMRI) in interrogations of terror suspects “has begun the transition from the world of fantasy to fact”.

He draws this belief from the unpublished views of a senior US interrogator, who is quoted in Prof Mark’s article as claiming that processes developed by “neuro-psychologists at London’s University College and Mossad” are “now being used to screen terrorists” with “great results”.

Further, a Department of Defence directive speaks of the need to include other “technical devices” to bolster the traditional polygraph lie detector in its “credibility assessment” of terror suspects.

Prof Marks warns of the “risk of mistreatment and abuse” of interrogation subjects in the event of a false positive.

While it has been suggested in recent years that the technique could possibly be used for lie detection, as lying uses different parts of the brain to telling the truth, there has previously been little suggestion that it is in current use.

fMRI techniques have been used for over a decade in diagnostic situations, to view brain tumours and other disorders. They work by using powerful magnetic fields to map tiny differences in oxygen usage in brain cells.

Since active cells use more oxygen than inactive ones, it is possible to see what brain areas are working when a statement is made – and in theory, whether it is a lie or a genuine memory.

However, Prof Marks says that while the technique has been tested on healthy people in low-stress environments, it is unclear whether they will work on terror suspects who may be being held in high-stress situations and who may have mental health issues that could be exacerbated by their incarceration.

Prof Marks also worries that while the images created require subtle interpretation, they may inspire false confidence in interrogators, leading to more aggressive treatment. This is particularly a concern in the wake of President George W Bush’s March 8 veto of legislation that would have prohibited the CIA using aggressive interrogation methods.

“One of the real concerns I have is that you can see how people can begin to say ‘the fMRI picked him out as a terrorist so let us give him a going over in the interrogation room,’ ” Prof Marks said in an interview with the American Association for the Advancement of Science’s website EurekAlert.

“Contrary to the view that fMRI will render torture obsolete, it might become a license for further abuse of detainees because its readings will convince people that they have a terrorist on their hands.”

However, Professor Daniel Langleben, a psychiatrist who specialises in brain imaging techniques at Penn State, says that such concerns are unfounded.

“Lie detection is not mind-reading. We do not detect terrorists, just deception,” he said.

Tom Chivers