Lie Detection

The use of fMRIs in a court of law as evidence, replacing the polygraph machine. They would be used to “prove” if a defendant is lying or telling the truth. Though scientists may understand the advanced technology of an fMRI, jurors certainly don’t, and the major worry is that the science will completely replace the law. With jurors basing their decisions based entirely off of the science, when it can be easily manipulated.

Polygraph testimony should excluded from court cases because it is unreliable, the technology is no better than the polygraph machine; it is one more subjective piece of information that informs decision making. Neuroscientists are worried about over-reliance on this technology, when you’re anxious there is all sorts of brain activity from the situation you are in. If you are innocent and you're being asked about the thing you're suspected of, you're going to be just as anxious as you are if you’re guilty of it.

Law is not going to disappear because of neuroscience. Getting a better handle on what brain machinery causes certain behaviors will change the criminal justice system, but it will not disappear. Neuroscience evidence of mental state may ultimately be admitted in trials, but it will not restrict the roles of judges and juries to reading brain scans.

When imaging is used to demonstrate damage to a victim's nervous system, a judge can expect that most evidence will be based on conventional clinical procedures. In cases involving victims, conventional CT scanning has dominated as the preferred diagnostic method. Less frequently, conventional X-rays, diagnostic MRI scans, electroencephalography and SPECT scanning of brain blood perfusion are used

The real question is how can neuroscientists present fMRI evidence in a court of law accurately and clearly enough that it can’t be interpreted in any other way. It requires a deeper understand of the neurology, one we don’t necessarily have.