Can a polygraph really tell if you're lying?  Depends on whom you believe. 
Lie detectors are still used in job interviews and dating shows.  The American Polygraph Association has hundreds of members who met in Nashville this week for the 44th annual conference.  As NewsChannel 5 reports, they're looking at internet innovations and other advances.  
But polygraph test results have not been allowed in criminal court cases for years, because they're considered too subjective and unreliable. 
A non profit group called antipolygraph.org is out to prove that polygraph testing is junk science.  The website claims you can beat the test by doing mental arithmetic, or biting the side of your tongue.