The simple answer is, no. You can now go back to work, content in that little tidbit of brain knowledge.
Functional magnetic resonance imaging (fMRI) is a fancy name for a brain scan that purportedly measures “brain activity.” What it actually measures is simply changes in blood oxygenation and flow in your brain, which we believe to be directly related to brain activity — but this is an indirect measure at best. It’s not actually measuring “brain activity.” fMRI scans are most often used in research to try and better understand our brains and how other things affect our brains (like mental illness or a specific cognitive activity).
So you can imagine the challenges that might be faced when you connect this kind of brain measurement to a legal proceeding. A review article on the use of fMRI for lie detection basically found that the science isn’t there.
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Hi John;
I wanted to add an issue regarding the efficacy of lie detection. As many people in the UK are aware there is a TV program called; ‘The Jeremy Kyle Show’ this is a daytime ITV television talk show which has been broadcasting since 4th July 2005.
The show is extremely popular and distinctive for its confrontational style, which sees guests attempt to resolve issues with family and friends, very similar to that of ‘Jerry Springer’ in the US.
On the show they exhibit ‘The Lie Detector Test’ which is advertised as being at least 96-97% accurate. The evidence is gathered by using a ‘Polygraph Test’.
‘The Polygraph Test’ results are generated by attaching 4 components to the subject. They then trace changes to the subject’s relative blood pressure and pulse rate and it is similar to the pressure cuff your doctor uses when taking your blood pressure.
“The results compiled can and do change people’s lives forever. Surely this cannot be a valid account of truth and must only propose an emotional relation to the questions at hand when administered?”
Read more;
http://www.dawnpugh.com/2010/05/07/does-truth-lie-in-detection/
Thanks
Regards
Dawn Pugh MBACP
Yes, certainly proponents of polygraphs will say it is “nearly impossible to beat” (not you, but others) and certainly I expect their trade association to say the same things.
But traditional polygraph tests are based upon 3 simple physiological components, all of which a person can learn to control if they want — breathing, blood pressure and sweating. Yes, biofeedback, for instance, can teach you how to gain control of all 3 of these things, and it’s easily learned and practiced.
At least with brain imaging, we’re talking about something you couldn’t beat so readily with biofeedback and relaxation techniques. So it does hold out hope for the future of lie detection, it’s just that we’re not really there yet.
If fMRIs are so “unreliable”, then how come several studies that have been conducted have proved that they do detect when the brain is lying?
Yes, like all other ‘sources’ their results can be skewed, but so can polygraphs. Ever heard of false negative, and false positive?