08 February 2006

The quest for truth

The growing reliance on functional magnetic resonance imaging (fMRI) to examine the brain in action is leading, inexorably, to the search for better lie detectors. At least two companies, No Lie MRI and Cephos are developing variants of this technology with several applications in mind.

At issue in all of this, of course, is the accuracy of the tests. Before anyone runs off and gets too excited about this new technology, it would be worth reading at least the abstracts of the academic papers (here and here) upon which the commercial strategies rest. It turns out that using fMRI provides accuracy in the range of 85-90%. Not bad, but hardly foolproof.

Of course, the reason that this is important is because of the famous case of Aldrich Ames, the CIA spy who was convicted for sying for the Ruskies in 1994. Ames succesfully deceived investigators using a polygraph, and has continued to watch the field of lie detection from Allenwood federal penitentiary. He sent a fascinating letter to Steven Aftergood at the Federation of American Scientists that is worth a read (I prefer the handwritten version, but you may wish to see the transcribed version). It seems that in the intelligence business, polygraphs are often used to coerce confessions from people, a conclusion that is hardly surprising given the current climate of paranoia.

The 'yuk factor' derives from the fact that this technology might breach a sanctuary that we all cherish, the privacy of thought. It may be only a minor comfort, but the truth of the matter is that scientists are still a long way off from reading your mind. So rest well.

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