Daniel Langleben and Jane Campbell Moriarty have an interesting new article that provides background on the use of brain imaging in criminal investigations, discusses obstacles to the use of the technology in courtrooms, and proposes a path forward. The type of imaging at issue is functional magnetic resonance imaging, or fMRI. Some research suggests that fMRI is indeed able to distinguish lies from honest answers during an interrogation. However, at least two courts have excluded fMRI evidence since 2010.
Langleben and Moriarty agree with these courts that there are some significant gaps in the supporting research, especially in light of the evidentiary rule of Daubert v. Merrell Dow Pharmaceuticals:
The most important piece in the puzzle is Daubert‘s “known error rate” standard. Determining the error rates for fMRI-based lie detection requires validation of the method in settings convincingly approximating the real-life situations in which legally significant deception takes place, in terms of the risk-benefit ratio, relevant demographics, and the prevalence of the behavior in question.
Langleben and Moriarty thus propose an ambitious program of clinical trials. They acknowledge that this would involve hundreds of participants and cost millions of dollars, but they believe the technology is promising enough to warrant the investment.
The article is “Using Brain Imaging for Lie Detection: Where Science, Law, and Policy Collide,” 19 Psych., Pub. Pol’y, & L. 222 (2013).