"We wondered how individuals assess the credibility of other people in simple social interactions. We found a strong correlation between amygdala and a baseline level of distrust, which may be based on a person's beliefs about trustworthiness of other people in general, his or her emotional state, and the situation at hand.
"What surprised us, though, is that when other people's behaviour aroused suspicion, the parahippocampal gyrus lit up, acting like an inborn lie detector," said Read Montague at the Virginia Tech Carilion Research Institute, who led a team that conducted the research.
For their research, the scientists used functional magnetic resonance imaging to study neural basis of suspicion.
Seventysix pairs of players, each with a buyer and a seller, competed in 60 rounds of a simple bargaining game while having their brains scanned. At the beginning of each round, the buyer would learn the value of a hypothetical widget and suggest a price to the seller.
The seller would then set the price. If the seller's price fell below the widget's given value, the trade would go through, with the seller receiving the selling price and the buyer receiving any difference between the selling price and the actual value. (MORE)
