The signature of the bluffing brain

Ed Yong in Not Exactly Rocket Science:

The best poker players are masters of deception. They’re good at manipulating the actions of other players, while masking their own so that their lies become undetectable. But even the best deceivers have tells, and Meghana Bhatt from Baylor University has found some fascinating ones. By scanning the brains and studying the behaviour of volunteers playing a simple bargaining game, she has found different patterns of brain activity that correspond to different playing styles. These “neural signatures” separate the players who are adept at strategic deception from those who play more straightforwardly.

In the game, a buyer and a seller negotiate over the sale of an imaginary object. The buyer is told about the object’s value in private and suggests a price to the seller, who then sets the actual price. If the price is less than the value, the deal goes ahead, the seller gets the price and the buyer gets the difference between that figure and the object’s value. If the seller’s price is too high, the deal is called off and no one gets anything. This goes on for 60 rounds and at the end of each, the players aren’t told about the outcomes.

Because of this set-up, buyers do best if they set low prices, because they stand to gain the most profits if the sellers accept. Sellers, however, prefer high prices to make the most from their sale. To play successfully, buyers have to keep in mind the object’s real value, the price that they offer, how they think the seller will react to their move, how they could make the most money, and how they can manipulate the seller to accomplish that.

More here.