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.

Triangle poker notables Greg Raymer and Michael Gracz, both national and “world” winners, could not be reached for comment Thursday. Other poker practitioners either couldn’t be reached or attributed their reluctance to comment to regular arrests at Triangle card games.

However, they said, some players are definitely better playing online than playing “live,” a split that would tend to back up the research indicating different parts of the brain are used for each form of the game.

In fact, what researchers found “very surprising” was that only the temporal-parietal junction was used 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.

“Social information may cause our brain to play by different rules than nonsocial information, and it will be important for both scientists and policymakers to understand what causes us to approach a decision in a social or a nonsocial manner,” Huettel said.

Receiving social information makes the brain play by different rules from those used in other settings.

“So, as we come to better understand what causes us to treat a situation in a social manner, there may be important applications to policies for shaping people toward more pro-social actions,” Huettel said.

The research was supported by the National Institutes of Health.

Goldsmith: 919-829-8929