On Tuesday evening, Yale scientists taught New Haven residents about the physiological reasons why Facebook can be addictive.

The talk was part of Science in the News, a lecture series run by the Yale Science Diplomats, a campus group devoted to educating the public about science issues and encouraging scientists to engage in the political process. More than 100 members of the New Haven community attended the talk at the New Haven Free Public Library on Elm Street, where two graduate students and a postdoctoral researcher discussed addiction and how it affects the human brain.

“We want to educate the community on scientific topics that they often see in the news,” said Jessie McDonald GRD ’12, spokeswoman for the Yale Science Diplomats. “We also want people to see what scientists really look like and to inspire high school students to pursue careers in science.”

At the talk, titled “Addiction in 2012: What Facebook, Xbox and Extreme Sports Do to Our Brains,” Kenneth Buck, a postdoctoral researcher in neurobiology at Yale, explained that the Internet may be considered an addiction. Viewing the Internet in this way could have consequences for questions of government policy, he said, such as whether Medicaid insurance should cover Internet addiction.

Buck also discussed the physiology of the brain, comparing the transmission of information between neurons to forwarding funny pictures of cats to friends over a phone.

Lu Jin GRD ’15 explained the mechanisms of addiction. Under normal conditions, she said, external stimuli cause a neurotransmitter called dopamine to be released by presynaptic neurons and received by postsynaptic receptors, producing a emotional response that is essential for survival. But she said that in the case of cocaine addiction, for example, dopamine can no longer return to the presynaptic cell, causing large quantities of the neurotransmitter to bind to the postsynaptic receptors and produce a “superhappy” response with negative long-term consequences.

Addiction “hijacks” the brain, altering behavior, Dipon Ghosh GRD ’15 said. Normally, the brain recognizes the distinction between short-term gains and long-term gains, balancing between the two in everyday life. But when suffering from addiction, he added, the normal balancing instinct is thrown off, causing the person to seek only short-term gains.

Ghosh used Facebook as an example of a potentially addictive agent in modern life. Stress can cause the brain to seek more pleasurable behavior, he said, leading people under stress to use Facebook more often and possibly become addicted.

Members of Yale Science Diplomats said they enjoy the opportunity to connect with the community.

Secretary of the group Mahala Burn GRD ’16 said she feels that graduate students have a responsiblity to share their scientific knowledge. Talks like those in the Science in the News series give graduate students the opportunity to discuss science with voting adults, said MacDonald, which is important helping them make informed decisions when casting votes in elections.

Victor Acorda, a New Haven resident who attended the talk with his three children and his wife Lenie, said it was educational and that he plans to come to another lecture in the series.

“Topics like these make the science real for day-to-day life, taking it out of the textbook and keeping you engaged,” Lenie Acorda said.

“Addiction in 2012” is one of six scheduled talks organized by the Yale Science Diplomats. The next talk, “Disease Detectives: Stopping Outbreaks Before They Stop You,” will take place March 27.