The Loneliness of the “Social Distancer” Triggers Brain Cravings Akin to Hunger

Loneliness hurts. But the feeling may serve a purpose. Psychologists theorize that it hurts so much because, like hunger and thirst, loneliness acts as a biological alarm bell. The ache of it drives us to seek out social connection just as hunger pangs urge us to eat. The idea is intuitively satisfying, yet it has long proved difficult to test.

On March 26, however, just as the COVID-19 pandemic gripped the world, researchers at the Massachusetts Institute of Technology posted a preliminary report on bioRxiv. The findings point to one telling conclusion: our need to connect is apparently as fundamental as our need to eat.

When they began the work three years ago, neuroscientists Livia Tomova and Rebecca Saxe and their colleagues wanted to demonstrate how loneliness operates in the brain. But enforced social isolation is so rare in healthy, nonincarcerated humans that it gave the team pause. By the time the researchers came to write their study this year, the unimaginable had become real. Now, Saxe says, “what feels most significant about this paper is that it’s a way to step outside the experience we’re having and look on it through a different lens.”

The paper describes a carefully designed experiment using functional magnetic resonance imaging (fMRI) to compare brain responses to loneliness and hunger. After a baseline brain scan, 40 adult participants underwent two 10-hour sessions: one in which they were deprived of food and another where they were denied social contact. The sessions served as control conditions for each other.

The researchers had the participants spend their time from 9 a.m. to 7 p.m. in a sparsely furnished room at the laboratory without phones, laptops or even novels, in case fictional characters provided some social sustenance. During the food-deprivation day, the subjects could not eat or drink anything but water over the same time frame.

Brain scanning immediately followed each deprivation session. In the scanner, the participants saw images of their preferred forms of social interaction and of their favorite foods, as well as a control image of flowers. “We found that this brain area specifically responded to the cues after deprivation but only to cues of what they had been deprived of,” Tomova says. The magnitude of the response correlated with the subjects’ self-reports of how hungry or lonely they were, although feelings of hunger were consistently stronger.

Even before the COVID-19 pandemic, an obvious next question for the work was whether different forms of social media could satisfy the need for social connection. Tomova is already working with researchers at the University of Cambridge to see if social media use during the pandemic might be remediating feelings of loneliness. “Twenty years from now,” Saxe says, “we will know what all the effects were of this experience we are having.”

from Scientific American Jun, 2020