The study, led by Dr. Read Montague, professor of neuroscience at BCM and director of its Brown Human Neuroimaging Laboratory, used functional magnetic resonance imaging (fMRI) to monitor brain activity in pairs of subjects during a social exchange game. The study made use of a new approach to studying social interactions, called hyperscanning, where two interacting brains are monitored simultaneously. The work revealed the existence of a new kind of map in the brain a "social agency map" that keeps track of "who" is responsible for an outcome during a social exchange between two interacting partners. The group found the map in an area of the brain called the cingulate cortex, which is known to be involved in bonding and social interactions.

Like the brain's sensory mechanisms that interpret and respond to sights and sounds, the process of building trust involves constructing models of other people and using those models as foundations for making decisions. Social decisions are among the most important kind for humans. "This is a region of the brain that is overdeveloped in humans and other social species and is a region you can monitor in social exchanges between people with either functional or dysfunctional social capacities," said Montague. "A degree of credit is something your brain has to assign before it ever starts assigning social agency. Your self-image, the degree to which you can carve yourself off from the rest of the world, is critical before you ever become a social creature."

Previous results from the same study, reported last year in Science, showed where and when trust forms in the brains of two anonymous peopl
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Contact: Ross Tomlin
htomlin@bcm.edu
713-798-4710
Baylor College of Medicine
18-May-2006