17 March 2009
"Defense attorneys are for the first time submitting a next-generation lie-detection test as evidence in court.
In an upcoming juvenile-sex-abuse case in San Diego, the defense is hoping to get an MRI scan, which shows activity levels based on oxygen levels in the brain, admitted to prove the abuse didn't happen.
The technology is used widely in brain research, but hasn't been fully tested as a lie-detection method. To be admitted into court, any technique has to be "generally accepted" within the scientific community...
Laboratory studies using fMRI, which measures blood-oxygen levels in the brain, have suggested that when someone lies, the brain sends more blood to the ventrolateral area of the prefrontal cortex.
In a very small number of studies, researchers have identified lying in study subjects with accuracy ranging from 76 percent to over 90 percent (.pdf). But some scientists and lawyers like Greely doubt that those results will prove replicable outside the lab setting, and others say it just isn't ready yet."
From Denny: We are forever chasing after ways to detect deceit. Just think Wall Street would have never taken us to the cleaners... but I digress. According to this interesting article this MRI version of the lie detector test could be vulnerable to a host of things:
"Ed Vul, an fMRI researcher at the Kanwisher Lab at MIT, said that it was simply too easy for a suspect to make fMRI data of any type unusable.
"I don't think it can be either reliable or practical. It is very easy to corrupt fMRI data," Vul said. "The biggest difficulty is that it's very easy to make fMRI data unusable by moving a little, holding your breath, or even thinking about a bunch of random stuff."
A trained defendant might even be able to introduce bias into the fMRI data. In comparison with traditional lie-detection methods, fMRI appears more susceptible to gaming."
By Alexis Madrigal