Here's another study (I hope this wasn't funded with taxpayer dough):

Brain scans show that the brains of people who are lying look very different from those of people who are telling the truth, U.S. researchers said on Monday.

Okay. So how would you go about setting up an experiment to test this hypothesis?

Would your experiment look anything like this?

Faro and colleagues tested 10 volunteers. Six of them were asked to shoot a toy gun and then lie and say they didn't do it. Three others who watched told the truth about what happened. One volunteer dropped out of the study.

While giving their "testimony," the volunteers were hooked up both to a conventional polygraph and also had their brain activity imaged using fMRI, which used a strong magnet to provide a real-time picture of brain activity.

There were clear differences between the liars and the truth-tellers, Faro's team told a meeting in Chicago of the Radiological Society of North America.

Bonus points for the first person to point out the two main problems with this approach, problems that a 6th-grade science fair entrant would have caught.