The Frontal Cortex

This is disturbing stuff. According to the Stanford Center for Law and the Biosciences, No-Lie MRI has recently produced a report that's being offered as evidence in a California court.

The case is a child protection hearing being conducted in the juvenile court. In brief, and because the details of the case are sealed and of a sensitive nature, the issue is whether a minor has suffered sexual abuse at the hands of a custodial parent and should remain removed from the home. The parent has contracted No Lie MRI and apparently undergone a brain scan.

The defense plans to claim the fMRI-based lie detection (or "truth verification") technology is accurate and generally accepted within the relevant scientific community in part by narrowly defining the relevant community as only those who research and develop fMRI-based lie detection. [Note: California follows its own version of the Frye test of admissibility, not the current federal test under Daubert.]

Limiting the "relevant community" to only those who research and develop fMRI based lie detection is without merit, if only because such a definition precludes effective or sufficient peer-review. Indeed, it is arguable such a narrowly-defined community has a strong incentive to exaggerate its claims of accuracy and overlook unanswered questions for financial gain if such techniques are "legally admissible."

I think we need to tread very, very carefully when it comes to incorporating fMRI data into the legal system. Brain scans can be incredibly useful, and have generated lots of really exciting research, but I worry about juries and judges subscribing to a false metaphor, which is that these massive magnets are accurate "windows" into the brain/mind/soul. (This is the "myth of transparency," which I've written about before.) It's important to remind ourselves that every fMRI image is highly processed snapshot of blood flow, not some magic readout of our secret thoughts.

And then there's the bias that's introduced when people are shown silhouettes of the skull, complete with splotches of primary color:

Deena Skolnick Weisberg, a researcher at Rutgers University, recently demonstrated how referencing brain scans can bias the evaluation of scientific papers. When she gave neuroscience students and ordinary adults a few examples of obviously flawed scientific explanations, people were consistently able to find the flaws. However, when the same explanations were prefaced with the phrase "Brain scans indicate" both the students and adults became much less critical.

In short, I'd want to see a lot more peer-reviewed work on fMRI and truth detection before I'd feel comfortable seeing brain scan data in court. Otherwise, I think it's too easy to be seduced and convinced by data that looks scientific (the Latinate anatomy! the cortical references! the expensive machines!) but might actually be shoddy pseudoscience.