I've just finished reading the hardcopy of a Wired article titled Don't Even Think About Lying. The first couple of pages detail the author's experience in a functional Magnetic Resonance Imaging (fMRI) machine that is supposed to produce a scan of his brain functions as he THINKS about things that are FALSE in his life and then things that are TRUE.
An image is eventually created which shows areas in the brain that are "hot" or "cold" depending on the portion of the exercise. According to the researcher, those areas that are responsible for emotion, conflict, and cognitive control "heat up" when you think about lying.
Further on, there are details of two commercial companies who are planning to market this kind of technology to individuals who believe they've been unjustly charged with a crime.
Would it surprise you to know that much of the research into this technology has been funded by DoD, DARPA, and DHS in the search for a "better mousetrap...um, lie detector?"
SO - here's the big question: is it a lie detector or is it simply a "diagnostic test?"