The Scientist has an article on the latest developments in the world of fMRI lie detection, looking at how accurate and reliable the technology really is.
This is a particularly hot topic because a commercial company, No Lie MRI, are marketing a brain scan lie detection service.
This is despite the fact that neuroscientists and the legal system are still unconvinced that it is accurate enough to be useful.
Interestingly, the company was partly funded by the US Government, and you can bet that they’ll be trying the system, even with the low accuracy rates, in case it proves useful for the secret services.
Probably the main advantage for most buyers is that is looks intimidating and high-tech.
Like with the polygraph test, many people put through the system will undoubtedly be more truthful because they believe that they will be caught if they lie.
In terms of its ability to catch genuine lies made by an individual, it’s still fairly limited though.
Not least because most brain imaging research is done as group studies. The results are usually based on average brain activity across all participants, rather than on any one individual.
Also, the studies don’t really resemble real-world conditions:
And in the real world, lying is verbal and carried out in defiance of instruction, and the stakes are incomparably higher. Rather than missing out on a $20 study reward, being caught in a lie could mean life in prison. Lying under these circumstances comes with an emotional component that is poorly elicited by a playing card, she argues.
“Applied fMRI studies of the kinds done so far have similar limitations to those of typical laboratory polygraph research,” according to a 2003 National Academy of Sciences report. “Real deception in real life circumstances is almost impossible to explore experimentally. You can’t randomly assign people to go do crimes. I do think that’s an inherent limit,” says Gabrieli, a professor of cognitive neuroscience. Others worry about the level of nuance that fMRI-posed questions can accommodate.
Still, researchers are hoping further studies will help improve the system, until, maybe, it will be the most accurate lie detection system in existence.
Until then, it’s an interesting field, but I wouldn’t bet your life on it.
Link to Scientist article ‘Watching the Brain Lie’.