Symposium Casts Doubt on fMRI “Lie Detection”

Emily Singer reports for the Massachusetts Institute of Technology’s Technology Review in “Imaging Deception in the Brain” (Wed., 7 Feb. 2007). Excerpt:

Polygraph tests are notoriously unreliable, yet thousands of employers, attorneys, and law-enforcement officials use them routinely. Could an alternative system using functional magnetic resonance imaging (fMRI), a technology that indirectly measures brain activity, better detect deceit? The U.S. government is certainly interested–it’s funding research in the area–and two companies have already sprung up to commercialize this use of fMRI. But a recent scientific symposium concluded that little evidence exists to suggest that fMRI can accurately detect lies under real-life circumstances. Scientists who attended the symposium worried that this new generation of lie detectors will follow the path of the polygraph–a widely used technology with little scientific support and broad potential to do harm.

“As we move forward, we don’t want to make the same mistakes as with the polygraph,” said Marcus Raichle, a neuroscientist at Washington University Medical School, in St. Louis, and a speaker on the panel, which was sponsored by the American Academy of Arts and Sciences, an independent policy research center in Cambridge, MA. He emphasized that, like the physiological changes monitored during polygraphs, the brain-activity patterns measured during fMRI are not specific to deception, making it challenging to identify a brain pattern that definitively identifies a lie.

“The great danger is that something like fMRI is adopted as a means of lie detection and becomes the standard before it has been scientifically evaluated for this purpose,” says Raichle in an e-mail written after the symposium. “The federal government does [approximately] 40,000 polygraphs a year, and I have heard speculation that as much as 10 times that amount may be being used in the private sector. If these numbers are anything like the real circumstance, then to have fMRI take over such an agenda prematurely would be very bad indeed.”

Comments 1

  • Science never has said we must know everything before we use what we know. They are setting standards they don’t use anywhere else in this type of research. Work does need to be done to ensure this is done right, so lets get off our duffs and do it. I was at a conference where the same concerns were lodged and how necessary it is to verify what is being done…just as long as the funds don’t come out of their particuar budgets! If this is so important compared to other fMRI research, how ethical is this? Focus on the science and let the public decide the politics of it.

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