Lie detection, can neuroscience identify lies?

Since the beginning of criminology, police officers and detectives have been trying to come up with  methods of detecting lies, stories and fibs. .It wasn't until the early 1920’s polygraphs have been used as an interrogation tool with criminals. The US law enforcement and federal government agencies such as the FBI and the CIA have been using them. This test works in a easy way, when someone lies it makes your heart race. It makes you pant, it drives up your blood pressure and in some extreme cases it makes you drip sweat. A polygraph machine detect lies by looking for signs of these physiological changes. But to often there have been times where the these test don’t actually work. Scientist have been coming up with ways that enhance and improve the way these test work by using neuroscience.  


“Scientists believe that a lie is made up of two parts: a person must create the lie and also withhold the truth”


After 9/11 the American government has become highly interested in procuring a sure-fire method of spotting liars. The American military has a whole department, the Department of Defense Polygraph Institute the need for a better test came along. These proponents believe the future impact of neuroscience “will be inevitable, dramatic, and will fundamentally alter the way the law does business” In this case there’s always going to be people who agree with polygraph test and people who think it’s a whole bunch of crap. Using neuroscience, scientist have come up with ways to use Functional magnetic resonance imaging (fMRI) to looks inside the brain instead of tracking outside measures of anxiety like changes in pulse, blood pressure or respiration. fMRI’s get the point straight across, you ask a question and if you lie the test shows it. Detection accuracy was claimed to be as high as 90% compared to a purported 70% for polygraphs making them more reliable and fast moving. There would be no need to use lawyers that would switch up your words and evidence. While some see this the best thing that could happen, and a bridge to a whole new world of lie detection and criminology others think this is just a waste of time.


Scientist believe the fMRI machines will only confuse results  “In theory, it takes more neural activity to lie than tell the truth because you have to construct a narrative, so the extent of neural activity can be relevant in determining whether you’re lying,” said Andrea Roth, an assistant professor at Berkeley Law.  In order to image an area where there is activity, a thought has to be made, and an image taken a couple of seconds afterward (because the oxygen conversion is not instantaneous). Stanford University’s Anthony Wagner decided to do a test where laboratory studies involve instruction to tell a low-stakes lie about an action they recently performed. However, in the real world, lies are self-generated, often high risk and emotionally charged, and lie detection may occur years after the event in question. This process must be repeated a couple of times to be able to filter out false positives. In the end there is no hard data to show that we can actually detect lies with great accuracy. We would all love it if neuroscience could distinguish between these true and false memories until then cops and detective will still to polygraph test.

fMRI’s are not a perfect science, and they have a long way to go before they can be perfect. I feel like with a good mixture between the test, lawyers and great evidence court cases will be easy to solve and won’t be hard to put people behind bars. There’s going to be a lot of work done and a lot of time put in before we can get anywhere to a point where test can really tell who’s lying and who’s telling the truth. We shouldn’t treat fMRI’s as if it’s the only thing that can and should be used in the court, we should seen more like another piece of evidence that could be icing on the cake to completely the case.


Brain Node 2
Brain Node 2

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