Conventional lie detection, using such measures as heart rate, respiration, blood pressure, Galvanic skin response, is so unreliable that resulting data are not typically admissible to courts in the United States. A panel of experts evaluating conventional lie detector results declared a third of the innocent to be guilty, while a quarter of the guilty “passed” [1]. These tests provide accurate measures of arousal. The problem is that innocent people can be aroused because they feel accused of wrongdoing, and psychopaths don’t get aroused by much of anything.
Consequently, the race is on to provide courts, employers, and law enforcement with better indicators of truthfulness. Lawrence Farwell uses an analysis of EEG that carries the unfortunate name of “brain fingerprinting.” According to Farwell, our EEG responds distinctly differently when we process something we recognize.
Others are looking at functional magnetic resonance imaging (fMRI) for clues to truthfulness. Sean Spence of the University of Sheffield recently appeared on a British reality show called Lie Lab. On one of the programs, they quizzed an accused murderer named Susan Hamilton. Hamilton’s imaging results, according to Spence, indicated that her brain was responding as if she were innocent, although he stopped short of saying that the technology “proved” her innocence.
Spence argues that the brain has to work harder when telling a lie than when telling the truth, and that this extra “work” shows up as higher activity in the ventrolateral prefrontal cortex, shown in blue in the photo above.
This technology is far from being ready for regular application, as much more research needs to happen. For example, Spence did not have an opportunity to take baseline readings on Hamilton due to the constraints of the television program (MRIs are hugely expensive). Consequently, it’s hard to tell if her brain activity during her interrogation was different than if she overtly told a lie, about her age for instance.
Nonetheless, we can assume that high-tech lie detection isn’t too far away, and in our enthusiasm for finding the “truth,” it’s likely that discussion of the ethics, limits, and privacy issues accompanying our new abilities will lag far behind.
1. Kleinmuntz, B., & Szucko, J.J. (1984). A field study of the fallibility of polygraph lie detection. Nature, 308, 449-450.
2. Spence, S.A., Kaylor-Hughes, C.J., Brook, M.L., Lankappa, S.T., & Wilkinson, I.D. (in press). ‘Munchausen’s syndrome by proxy’ or a ‘miscarriage of justice’? An initial application of functional neuroimaging to the question of guilt versus innocence. European Psychiatry.
5 Comments
nichol.myers · November 20, 2007 at 12:06 pm
It is unfortunate that Spence never got a baseline for the study on Susan Hamilton. Of course, this all but null and voids the results (in my mind, at least — perhaps I’m being a bit close-minded). However, I do believe that as Americans, and with access to technology (and oodles of boredom, as it were) we will eventually find out the inner workings of humans minds, be it lies, gambling practices, or simply what one’s brain does during TV watching.
I look forward with intense anticipation for things to come, as this finding with the fMRI could be a breakthrough for those that are wrongly accused and imprisoned for crimes.
Laura Freberg · November 20, 2007 at 10:32 pm
My guess is that somebody will follow this up on a larger scale soon, as the commercial applications would likely make up for the high cost of doing the necessary clinical trials.
JacobAlv87 · November 21, 2007 at 10:21 pm
I think this type of technology is so interesting! I always wondered how I would do on a lie-detector test. I like to think of myself as a very honest person, but I’m also one of those people who gets “nervous” when I am accused of something, despite my innocence. For example, my mom would ask me if I ate all of her chocolate and I’d automatically start laughing nervously. This made me seem guilty or that I was lying! Luckily she believed me though. Also, this technology reminds me of the movie I just watched; Oceans 13. In the new “Banks Casino” they have the latest technology that can detect when a high roller is cheating based on cameras that can sense pupil dilation or heartbeat.
DanielHarris fallqtr · December 6, 2007 at 8:15 pm
I feel like this type of lie detection would be very hard to use as hard evidence. There is so much variability among different individuals, I think it would be entirely too subjective. I just learned in my personality class that introverts and extraverts respond differently to the same stimulation such as noise for example. How do we know that one person is going to respond to the same degree, or even at all, comparatively to another person? I think we can all agree that there is something not quite “normal” about psychopaths. It would be hard to know if brain activity could be expected to be “normal” as well. Also, the web site stated that it had very good success rate in experimental testing. For me at least, there is definitely a different feeling between sitting down for some experimental questioning and being interrogated for a crime. Physiologically, I feel like I would be an entirely different person in each situation. In conclusion, I feel like with the complexity of the human brain, and our severely limited knowledge in this regard, technology like this is a long way off from being an effective tool.
amandam · March 6, 2008 at 6:14 pm
This is a very interesting article but knowing a little about the fMRI makes me question the situation. I agree that a commercial version might me a better idea. I question the negatives such as high costs and possible side effects from the high magnents with the fMRI. I wonder if these would be possible side effects even with a commerical version. But even measuring brain activity, how do we know for sure that a person is not telking the truth. What if the high brain activity is due to something else? This still sounds iffy to me.
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