I recently took a polygraph for a pre-employment screening for a local police dept. and passed the "lie detector with flying colors. I bit my tongue and tightened my anus doing the control questions and passed.
Where does it say to bite your tongue?
Tongue-biting is one of the countermeasures described in Chapter 4 of The Lie Behind the Lie Detector (http://antipolygraph.org/lie-behind-the-lie-detector.pdf).
Oh yeah, I was thinking of How to Sting the Polygraph.