Researchers in the US who scanned the brains of volunteers while they tried to trick each other in a bargaining game found it was possible to detect unique brain signatures among the successful bluffers.
You can read how Dr Read Montague, a professor and computational neuroscientist at the Baylor College of Medicine in Houston, Texas, and colleagues, made this discovery in a study published on 1 November in the Proceedings of the National Academy of Sciences, PNAS online journal.
Bluffing is the ability to manipulate the way other people read us. When we interact with other people we build social models of them in our brains. Montague and colleagues are interested in how people manipulate their social model in the brains of others.
They wrote that the computations in these models and how we manipulate them are “difficult and poorly understood”, so they decided to investigate one particular area: strategic deception, which they defined as “our ability and willingness to manipulate other people’s beliefs about ourselves for gain”, an important skill for bluffing one’s way convincingly through a game of poker.
For their study, Montague and colleagues took MRI scans of the brains of 76 volunteers while they took part in a one-to-one bargaining game while they also measured their behaviour and typified into three types.
The point of the game was to be a deceptive buyer and trick the other player into selling items for less than their true value. There were several rounds in a game, and in each one the researchers told the buyer the true value of an item who would then suggest a price to the seller, who then decided what the final selling price would be.
The study revealed three types of buyer: one type was always honest and revealed the true value every time, another type always suggested a price that was lower than the true value.
But the third type, which the researchers called “strategists” were able successfully to bluff their sellers; they gained their trust by offering to pay more than the real value for low value items, but then offered under the value for high value items. They also emitted “behavioral signals that mimicked a more benign behavioral type”.
The strategists made more “profit” overall because although they lost money by paying more for the low value items, it was much less than the money they gained overall when they paid a pittance for the high value items.
But what was even more interesting, was that the researchers found differences in the brain scans of the players in each behavioural type: they were “distinguished by neural data measured during the game”.
The brain scans of the most deceptive players showed “differential activation in right dorsolateral prefrontal cortex and left Brodmann area 10” at the time of their deception, and strategic types showed a “significant correlation between activation in the right temporoparietal junction and expected payoff” that the other types did not show.
The researchers concluded that the “neurobehavioral types” that they identified in this study, could lead to measurable biomarkers for bluffing, or in their words, the “capacity to manipulate and maintain a social image in another person’s mind”.
However, as one expert commented, just because some of the players did not bluff, it did not mean they did not have the ability to.
Steve Fleming at University College London told New Scientist magazine that it would be interesting to consider whether “non-deceptive players have the same capacity to bluff, but choose not to”.
“Neural signatures of strategic types in a two-person bargaining game.”
Meghana A. Bhatta, Terry Lohrenza, Colin F. Camererb, and P. Read Montague.
PNAS, Published online before print 1 November 2010
DOI: 10.1073/pnas.1009625107
Additional source: New Scientist.
Written by: Catharine Paddock, PhD