As far as the CVSA goes, can anyone explain the basics of how it works and what countermeasures are effective?  Someone told me that when they give you a control question, you answer the question while placing your tounge in a unique position.  For example, if the contro question is " Other than what you told me, have you ever told a lie?"  You would answer no and while saying "no" you would curl your tounge a little bit so that the "no" sound a little different.  just a little different so that the "tester" can not tell.  When answering the relevent questions, you would say "no" with your normal tounge movements.  Any thoughts or input on that?  Any other countermeasures for the CVSA?