The Guardian published a very interesting article about lie detectors wrote by Jamie Horder. In it, Horder stresses the fact that while these devices are hailed as a powerful weapon against crime – usually by those that profit from them – the fact remain that we still lack the technology and the knowledge to correctly say that someone lied or concealed information based on the results of these tests, be it polygraphs, EEG or fMRI. Here’s an excerpt of Holder’s article:

Wouldn’t it be amazing if there was a machine that could tell you whether someone was telling the truth? It would, of course, be really useful – but more than that, it would represent the ultimate triumph of technology. The utterly private world of our consciousness would be private, and sacred, no more.

Given how fascinating the idea is, then, it’s no surprise that there have been plenty of attempts to design technological lie detectors, and no shortage of people willing to pay for the chance to use them. All of them have worked, in theory. But that doesn’t mean they work.

You can read the rest of the article here. And if you really are interested in this subject, you can read a blog post by Steve Novella on the same subject here. Here’s a small sample of it:

Several studies, summarized in a good review by Joseph Simpson, found that researchers can, with about a 90% accuracy, detect when a subject is lying based upon their fMRI activity. (…)

However, the results of this research must be placed into context. The question is – can they be applied to real world settings? And the answer is – we don’t know, because the proper research has not been done.

I recently blogged about a case where fMRI evidence wasn’t allowed in court. You can read it here.