Heartbreak Hurts, Scientists Say

Most people know that rejection hurts. But new research from the University of California at Los Angeles (UCLA) suggests that rejection really does hurt.

According to the study, led by social psychologist Naomi Eisenberger, being dumped, excluded or abandoned by a loved one can register in the brain just like a punch in the stomach or a stubbed toe. The finding implies that terms such as “hurt feelings,” “emotional pain” and “broken heart” aren’t simply metaphors: they may have arisen from physical experience.

The researchers used a functional magnetic resonance imaging (fMRI) machine to monitor the brain activity of 13 college students as they played a computer game called “Cyberball.” In the game—which is “really the most boring game you can imagine,” according to study co-author Matt Lieberman—one player, controlled by a human, tosses a ball back and forth with two computer-controlled players. But, in the study, the student participants were led to believe that the two other players in the game were being controlled by fellow students—not by the computer.The students were asked to play three rounds of the game under the vigilant eye of the fMRI. But, when the first round began, they were told that due to “technical difficulties,” they couldn’t participate, and were asked to watch the other players play while the problem was being fixed. In the second round, the participants were able to play and the game proceeded normally. Then, in the last round, the game started off normally, but for the last three-quarters of it, the two computerized players “ignored” the human player and kept the ball to themselves—as the researchers had programmed them to do.
The ACC: An Isolation Alarm

Eisenberger and her team then compared the fMRI data from each of the three rounds, looking closely at activity in the anterior cingulate cortex (ACC), a brain region involved in responding to physical pain. They found that during the first and third rounds of Cyberball (those in which the participants couldn’t play for either part or all of the time), the participants experienced more ACC activity than they did during the second round.

The ACC has been shown to function as a “neural alarm system” for physical pain: it registers pain and decides whether an automatic response, such as pulling one’s hand away from an unexpectedly hot stove, is needed. But Eisenberger’s study suggests that a similar “ACC alarm” goes off when an individual feels isolated from others—when he or she can’t participate in a game, for example. And, the ACC appears to respond the same way to any kind of social exclusion, regardless of whether it’s someone else’s “fault,” as when one’s fellow players refuse to pass the ball, or the result of extenuating circumstances such as technical difficulties. “It seems that if you are being left out in any kind of way, you will see ACC activity,” Eisenberger explained in an email.From an evolutionary standpoint, it makes sense that humans would have evolved a neural mechanism to respond to social exclusion. “Going back 50,000 years, social distance from a group could lead to death and it still does for most infant mammals,” Lieberman said. “We may have evolved a sensitivity to anything that would indicate that we’re being excluded. This automatic alarm [in the ACC] may be a signal for us to reestablish social bonds before harm befalls us.” The researchers believe that this “social exclusion alarm” probably evolved out of our system for responding to pain, which had already been established, and that’s why the two “alarms” use some of the same mechanisms.
Why It Feels Good to Talk?

But the researchers also found that oddly enough, the human brain may be able to override this knee-jerk reaction to social exclusion simply by thinking about the isolating experience. They interviewed the students about how they felt during the last round when the other players ignored them. Some of the students complained of feeling “invisible” and “rejected.” “They came out of the scanner saying, ‘Did you see what they just did to me?'” said Eisenberger. But others suspected (correctly) that the researchers had staged the third round to see how they’d react to being ignored.

The fMRI data showed that students who reported feeling upset as a result of being excluded experienced the most activity in the ACC region, suggesting that the greater the intensity of one’s “hurt feelings,” the greater the activity in that part of the brain. Meanwhile, those students who thought the round had been staged had low ACC activity.Common sense suggests that the skeptics didn’t have much ACC activity because, having figured out that the researchers were up to something, they weren’t insulted when the other players ignored them. But this contradicts the study’s finding that the ACC is activated whenever one finds oneself isolated from a group, regardless of the reason. So, although some of the students concluded that their fellow players weren’t to blame, this doesn’t explain why their ACCs didn’t light up: they were still excluded from the game, so theoretically, their ACC alarm should have gone off.It’s possible that some of the skeptical students might have suspected that the other Cyberball players were computer-controlled. This might have diminished their ACC response because they didn’t think they were being excluded from a real, human community. However, when interviewed by the researchers, most of the skeptics indicated that they believed the other players were humans. Moreover, studies have shown that people can feel insulted even when they know they’re playing with a computer. “Even if you tell people that they are playing (the same Cyberball game) with a preset computer program and that the program is set to exclude them at a certain point in time,” Eisenberger said, “the person playing with the computer still feels badly after the game.”

To unravel this mystery, the researchers returned to the fMRIs, and discovered that the students who figured out the researchers’ scheme had low ACC activity, but unusually high activity in another part of the brain: the right ventral prefrontal cortex (RVPFC). The RVPFC is involved in a wide variety of tasks, such as problem-solving, thinking about emotions and exercising self-control. Eisenberger and her team concluded that the skeptical students spurred this portion of the brain into action by thinking about their situation, in an attempt to figure out why they were being ignored.The researchers then hypothesized that the increased RVPFC activity in the skeptics played a role in diminishing ACC activity. A correlation between high RVPFC activity and low ACC activity had been previously demonstrated in studies of physical pain. In rats, for example, “electrical stimulation of VPFCdiminishes pain behavior in response to painful stimulation,” according to the researchers. And “in humans, heightened RVPFC activation has been associated with improvement of pain symptoms.” Thus, in observing the same kind of interaction between the two brain regions in their experiment on social exclusion, Eisenberger and her team may have uncovered yet another similarity between the brain’s responses to physical and emotional pain.By linking the process of thinking about one’s emotions—as the skeptical students did—to a decrease in ACC activity, the researchers may have discovered why writing or talking about negative emotions helps to alleviate them. “Verbalizing distress may partially shut down areas of the brain that register distress,” Lieberman said. “The regulating abilities of the prefrontal cortex may be why therapy and expressing painful feelings in poems and diaries is therapeutic.” The study, published in the October 10, 2003 issue of the journal Science, is thought to be the first to examine feelings of rejection using an fMRI machine. “It’s fabulous that they brought social interactions into the [fMRI] magnet,” social psychologist Susan Fiske, of Princeton University in New Jersey, told ScienceNOW. Scientists hope that studies like this one will help us develop new therapies for people dealing with rejection and loss.

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