Researchers at the RIKEN Brain Science Institute (BSI) in Japan have uncovered two brain signals in the human prefrontal cortex involved in how humans predict the decisions of other people. Their results suggest that the two signals, each located in distinct prefrontal circuits, strike a balance between expected and observed rewards and choices, enabling humans to predict the actions of people with different values than their own.
The authors found that humans simulate the decisions of other people using two brain signals encoded in the prefrontal cortex, an area responsible for higher cognition. One signal involves the estimated value of the reward to the other person, and is called the reward signal, referring to the difference between the other’s values, simulated in one’s mind, and the reward benefit that the other actually received. The other signal is called the action signal, relating to the other’s expected action predicted by the simulation process in one’s mind, and what the other person actually did, which may or may not be different. They found that the reward signal is processed in a part of the brain called the ventromedial prefrontal cortex. The action signal, on the other hand, was found in a separate brain area called the dorsomedial prefrontal cortex.
Nakahara believes that their approach, using mathematical models based on human behavior with brain imaging, will be useful to answer a wide range of questions about the social functions employed by the brain. “Perhaps we may one day better understand how and why humans have the ability to predict others’ behavior, even those with different characteristics. Ultimately, this knowledge could help improving political, educational, and social systems in human societies.”