IE 11 is not supported. For an optimal experience visit our site on another browser.

I knew you were about to do that

By Jennifer Welsh


Humans may not be mind readers, but our brains are able to predict other people's decisions pretty well. New research on this phenomenon shows that two spots in the brain weigh the risk and reward of the choice someone else is making.

"Perhaps we may one day better understand how and why humans have the ability to predict others' behavior, even those with different characteristics," Hiroyuki Nakahara, of the RIKEN Brain Science Institute, in Japan, said in a statement. "Ultimately, this knowledge could help improve political, educational and social systems in human societies."

To study this, 39 participants watched another person play a game (on a computer screen) and predicted what choices that person would make based on the person's prior moves. Meanwhile, the researchers scanned the players' brains using functional magnetic resonance imaging (fMRI), a technique that can detect brain activity.

They then used this information to build a computer model of the brain-activity patterns that appeared while the participants were trying to decipher someone else's decisions.

The researchers found activity spiked in two areas of the brain's prefrontal cortex when participants were sort of reading the minds of their opponents.

One of these brain areas estimates how rewarding any given decision would be to the other person, and is called the reward signal. The other signal is called the action signal, which involves the other person's expected action and what the other person actually did, which may or may not be different. The researchers think these brain spots work together to find a balance between the expected and observed rewards and choices.

"Every day, we interact with a variety of other individuals," study researcher Shinsuke Suzuki, also of RIKEN, said in a statement. "Some may share similar values with us and for those interactions simulation using the reward signal alone may suffice. However, other people with different values may be quite different and then the action signal may become quite important."

The study is detailed in tomorrow's (June 21) issue of the journal Neuron.

More from LiveScience: