[mos_basik]

Maybe you could induce something similar by providing the liar with strong incentives / stress. Something like this:

>We're going to hook you up to a state-of-the-art polygraph. We know you've heard that polygraphs are snake oil, but we think we've made a breakthrough on this one, which is why we're running this test. Answer truthfully to all questions except the five on this shortlist. For any of listed questions, you may choose to lie. If you tell one undetected lie, you get $5. For each additional undetected lie, your payoff is multiplied by 1.9. If any of your lies is detected, you get no money and you get shocked. The intensity of the shock has a similar exponential relationship with the number of lies you told.

If shocking volunteers doesn't get past the ethics committee, then maybe you start off the volunteers with a baseline payout of $50 or so and allow the payoff to both grow and decrease exponentially. The goal being that on that fifth lie, they're really on the edge, knowing that they could either make a lot of money or get {shocked,nothing}.

[itronitron]

how about this -> we are going to tell you how to defeat the polygraph, which is easy because it is actually mostly BS, and we will pay you $100K if you successfully deceive the polygraph when the examiner asks you if you have been told how to defeat the test.

Then tell the polygrapher that everyone will lie on that question so they should flag all responses as lies. Then everyone's results can be evaluated by another polygrapher to determine who was lying 'well', with no payout needed.