BRAIN-SCANNING techniques that test whether people are telling the truth could soon be sufficiently reliable to be used to interrogate criminals...The technique works by monitoring activity in the frontal lobes of the brain, which have to work harder than normal when giving answers that are not truthful. Rugen Gur, a colleague of Dr Langleben, said: “A lie is always more complicated than the truth. You think a bit more and fMRI picks that up.”
Well, I certainly see no potential for abuse here.
Wonder what would happen to the results if on every answer--even those you were telling the truth on--you'd do a math problem in your head before speaking?