TUESDAY, Nov. 2 (HealthDay News) -- Attention swindlers, grifters and expert poker players: Science may be onto you.

Researchers report that they've used brain scans to figure out how people's minds work differently when they're trying to manipulate others into believing something that's not true. Or, as it's most commonly known, bluffing.

The findings hint at how complicated bluffing is compared to, say, simply telling a lie.

"Our study indicates that manipulating other people's beliefs about your likely actions over a period of time probably requires a few different cognitive processes, including the ability to understand how your previous actions will affect other people," explained study author Meghana A. Bhatt, a fellow at Baylor College of Medicine's department of neuroscience.

Bluffing is commonly thought of as a part of gambling games like poker. But it happens in other scenarios, such as during an auction or while bargaining over a car purchase or a salary.

In the new study, researchers monitored the brains of 76 volunteers while they took part in a "bargaining game" designed to coax them into bluffing. One person served as the buyer and another as the seller during 60 rounds.

"One subject, the buyer, knows the true value of an object and suggests to the other subject, the seller, what price they should sell the object for," said study co-author Read Montague, a neuroscientist. "But the seller knows that most buyers will 'shave' the price a little to get a better deal. Also, the buyer knows that the seller will expect this, so the suggested price from the buyer needs to be credible. You can see that both players must use their best guess about the other player's assumptions about them. They must understand their image in their opponent's mind."

The ability to do all this "is a sophisticated cognitive ability in humans, and it is one part of a collection of cognitive abilities that allows us to deal with other humans, including cooperating with them," said Montague, a professor of neuroscience at Baylor.

The researchers report their findings in this week's online issue of the Proceedings of the National Academy of Sciences.

"There was a very significant difference in brain responses in the so-called bluffers" compared to those who were honest, Montague said. "The bluffers are likely [using] neural circuitry devoted to understanding what others believe in the context of the game."

Bhatt put it this way: "We believe the areas indicate that the strategists -- bluffers -- are essentially thinking ahead. Specifically, they're keeping track of how their suggestions are changing their reputation in the seller's mind and are in turn improving or harming their chances at good payouts in the future."

Paul J. Zak, director of the Center for Neuroeconomics Studies at Claremont Graduate University in Claremont, Calif., was skeptical about the study's worth since it doesn't reveal much that's new about bluffing. It's "fun and amusing, very well-designed and executed, but of little value I think," he said. "I'm not seeing clear value to this study for normal humans."

More information

For more about the brain, try the U.S. National Institute of Neurological Disorders and Stroke.