Can people with brain injuries be polygraphed?
On One Hand: It Doesn’t Scan the Brain.The polygraph doesn’t measure brain activity but rather physiological reactions such as changes in heartbeat, blood pressure, respiration and electrical resistance caused by sweating, according to Polygraph Investigative Service. Therefore, as long the individual’s brain is not damaged to the extent that it restricts these natural reactions to stress, a polygraph could theoretically work to detect lies.On the Other: The Brain Damage May Distort Stress Reactions.If the brain injury causes something akin to mental retardation or difficulty grasping concepts, the polygraph is not likely to be effective, according to Dr. LeRoy A. Stone, a psychologist and forensic diplomat. His experience working with the mentally impaired led him to believe that polygraphs were an exercise in futility.Bottom LinePolygraphs are controversial when used on healthy individuals, and many states do not admit their results into court.
