fMRI Lie Detection Hearing Ends, Decision Still to Come

A federal court in Tennessee heard arguments yesterday and today on whether lie detection technology based on fMRI scans of brain activity should be admitted in a criminal case involving a psychologist accused of defrauding Medicare. Magistrate Judge Tu Pham presided over the pretrial hearing and could issue his report anytime between now and 1 June, when the trial begins.

The hearing provided the most formal legal test yet of whether fMRI lie detection meets the so-called Daubert standard for admitting evidence in federal court, and as such it could set an important precedent.

Last year, attorneys made a request to introduce fMRI lie-detection evidence from California-based company No Lie MRI in a sexual abuse case in southern California (to demonstrate that the defendant was telling the truth). But they withdrew it after prosecutors lined up expert witnesses to testify about the shortcomings of the method. And in a pre-trial hearing last week for an employer retaliation case, a judge in New York rejected an attempt to introduce fMRI lie detection evidence from Cephos, the same Massachusetts-based company involved in the Tennessee case. The New York plaintiff's attorneys had hoped to use fMRI scans and expert testimony from Cephos to demonstrate that one witness was telling the truth, but the judge ruled that establishing the credibility of a witness is the job of the jury, not of expert witnesses.

fMRI brain scans have been introduced previously in the sentencing phase of a murder trial (to indicate that the defendant had a brain disorder and should be spared the death penalty). But legal scholars say the requirements for admitting evidence at sentencing are generally less stringent than those for a trial to determine innocence or guilt.

Unlike the previous cases involving fMRI lie detection, the court in Tennessee heard testimony directly related to the scientific validity of the technology. Judge Pham's report will take the form of a recommendation to trial judge Jon Phipps McCalla. (Although the trial judge ordinarily would be the one to preside over a pretrial hearing, McCalla had a schedule conflict and Pham took his place).

Stay tuned to ScienceInsider for more details as they emerge.