Stanford Study Finds that Mind Reading fMRIs Are Not Ready for the Courtroom
Functional magnetic resonance imaging (fMRI) machines are the talk of the town. (source) Recently, there has been much interest in using these images in the courtroom.
Last week, Gothamist reported that
One Brooklyn attorney wants to use an fMRI brain scan to get to the bottom of a sexual harassment case, and if it works, it could be a legal milestone. The fMRI measures blood-oxygen levels in the brain, and according to lab studies [PDF] the brain sends more blood to the ventrolateral area of the prefrontal cortex when a person lies. By placing a person’s head inside an MRI scanner build with an electrical magnet 10^5 times more powerful than the Earth’s magnetic field, scientists can get a 3D image of the brain’s blood concentration. Noting that “detecting deception is only an indirect path to the truth through elimination of false leads,” the studies have been able to “detect” lies up to 90% of the time.
But the judge put the kybosh on it. And it sounds like that was the right decision.
On Monday, Stanford University News reported on a study that showed that fMRIs are not ready for the courtroom. The study focused on whether the machines could decipher people’s memories, and by doing so tell us whether individuals were lying or not. But the findings, published in the Proceedings of the National Academy of Sciences, show that fMRIs can’t tell the difference between true and false memories. The team of Stanford researchers concluded that fMRIs are “able to measure how strong their subjects sense of a specific memory was. But they could not tell for sure whether the memories themselves were based on a recollection of an actual experience.” The fMRIs, in other words, might be accurate at distinguishing whether people think they remember something happening, but not whether it actually did happen.
And the researchers doubt the technology will ever be accurate enough to use as evidence in court:
“We are by no means at the level you’d want for a technique that might be used in a courtroom to probe a defendant’s memory and uncover the truth about his or her past experiences[.] Brain imaging analysis will definitely develop, but I’m doubtful that the technology will ever be capable of providing a 100 percent reliable determination of whether somebody actually had a particular experience.” (source)
The results of this study should end any debate about the admissibility of fMRIs.
Bonus Video: Mythbusters episode where one member of their team easily tricks an fMRI.
Tiny top hat tip: Tom B.