RALEIGH, N.C. — Poker players rely on a special region of the brain, as well as a poker face, when deciding whether to bluff or call, according to Duke University research made public Thursday. 

As proof, the region reacted differently when someone was playing a human or a computer.

The research could be used in learning more about human emotions such as empathy. Researchers observed the neural reactions of people competing at a poker game, both against a computer and against an opponent the participants knew to be human.

Neural imaging showed that a region of the brain called the temporal-parietal junction carried information that was unique to making decisions about who might be a worthy opponent and whether to bluff the opponent, the research shows. Carried out by researchers for the Duke Center for Interdisciplinary Decision Science, the results appeared in Thursday’s edition of the journal Science.

“Often the brain is considered to have an entire ‘social network’ comprising a number of regions that help us interact with others in social contexts,” center director Scott Huettel, senior author of the study, said via email.

“Our analyses looked at all of those regions and found that all but one responded in essentially the same way against the human and computer opponents,” said Huettel, a professor of psychology and neuroscience at Duke.

What researchers found “very surprising” was that the temporal-parietal junction was used only in making decisions in interactions with another person.

Lead researcher McKell Carter, a postdoctoral fellow at Duke, said the region on the edge of the brain combines information gleaned by attention and by biology, such as, “Is that another person?” People like to be social, and so paid greater attention to their human opponents than to their cyber foes.