How the Brain Made Room for Complex Social Ties

When APS Fellow and Janet Taylor Spence Award recipient Naomi Eisenberger was a graduate student, she ran an experiment in which study participants felt socially excluded: Participants situated in an fMRI machine played a virtual game of catch with two other players — or so they thought. In truth, they were playing catch with a computer, and no other human player was participating in the game. At some point, the other “players” quit passing the ball to the study participants, which led to feelings of exclusion.

In an interview with June Gruber for the Experts in Emotion series, Eisenberger says she was shocked when she compared her data to the data of a colleague who was running a study on experimental pain administration in irritable bowel syndrome patients.

“We each had our data up on our computer screens, and at some point we noticed just how similar our data looked,” Eisenberger said. “I was looking at a study on social rejection, she was looking at a study of physical pain in patients, and at some point, it became hard to tell which study you were looking at.”

Since social connectedness is extremely important for human survival, Eisenberger thinks that the brain has, as a result of evolution, adapted the systems already in place to help us avoid physical pain to also help us avoid social isolation, a state that is strongly correlated with health risks even to a similar degree as smoking cigarettes.

More recently, Eisenberger has focused on some of the more positive ways in which the human brain may have adapted to encourage social connectedness. She is currently working to identify “more basic neural systems” that have been adapted to reinforce social connectedness. This follows the same vein of her earlier work identifying basic neural systems that respond to social pain. One experiment has shown that key neural circuitry activated by physical sensations of warmth is also activated when study participants read warm, meaningful notes written by their loved ones.

In the long term, Eisenberger says that she would like to contribute to the development of an overarching theoretical framework for the neural basis of emotions.