The psychologist Naomi Eisenberger describes herself as a mutt of a scientist. Never quite fitting the mould of the fields she studied – psychobiology, health psychology, neuroscience – she took an unusual early interest in what you might call the emotional life of the brain. As a doctoral student at the University of California, Los Angeles (UCLA), Eisenberger found it curious that we often describe being rejected in terms of physical pain: ‘My heart was broken’, ‘I felt crushed’, ‘He hurt my feelings’, ‘It was like a slap in the face’. More than metaphors, these expressions seem to capture something essential about how we feel in a way that we can’t convey directly. And you’ll find similar ones not just in English but in languages all over the world. Eisenberger wondered why. Could there be a deeper connection between physical and emotional pain?
In a landmark experiment in 2003, Eisenberger and her colleagues had test subjects strapped with virtual-reality headsets. Peering through goggles, the participants could see their own hand and a ball, plus two cartoon characters – the avatars of fellow participants in another room. With the press of a button, each player could toss the ball to another player while the researchers measured their brain activity through fMRI scans. In the first round of CyberBall – as the game became known – the ball flew back and forth just as you’d expect, but pretty soon the players in the second room started making passes only to each other, completely ignoring the player in the first room. In reality, there were no other players: just a computer programmed to ‘reject’ each participant so that the scientists could see how exclusion – what they called ‘social pain’ – affects the brain.
Physical pain involves several brain regions, some of which detect its location, while others, such as the anterior insula (AI) and the dorsal anterior cingulate cortex (dACC), process the subjective experience, the unpleasantness, of pain. In fMRI scans of people playing CyberBall, Eisenberger’s team saw both the AI and the dACC light up in participants excluded from the game. Moreover, those who felt the most emotional distress also showed the most pain-related brain activity. In other words, being socially rejected triggered the same neural circuits that process physical injury, and translate it into the experience we call pain. [Continue reading…]