After months of social distancing, it’s no surprise that many people have felt hungry for human companionship. Now, a study from MIT has found that for our brains, the desires we feel during isolation are indeed similar to the food cravings we experience when we’re hungry. After the subjects endured a day of total isolation, looking at photos of people having fun together activated the same region of the brain that lights up when someone who hasn’t eaten all day sees a picture of pasta.
“People who are forced to be isolated crave social interactions the same way a hungry person craves food,” says Rebecca Saxe, professor of cognitive science, PhD ’03, lead author of the study. . “Our finding corresponds to the intuitive idea that positive social interactions are a basic human need.”
The research team collected the data in 2018 and 2019 as part of a larger research program focused on how social stress affects behavior and motivation.
For the study, they confined each of the 40 volunteers alone to a windowless room for 10 hours without access to their phones, although they could use a computer to contact the researchers. “They had to let us know when they were going to the bathroom so that we could make sure it was empty,” says Saxe. “We delivered food to the door, then [messaged] them when he was there. They really weren’t allowed to see people. When the time was up, the participants were scanned in an MRI machine – after being trained to enter it without any assistance.
On a different day, the participants fasted for 10 hours, again followed by an MRI. During the scans, they were shown pictures of food, pictures of people interacting, and neutral pictures such as flowers.
When isolated subjects saw photos of people enjoying social interactions, researchers recorded a specific pattern of activity in substantia nigra, a tiny structure in the midbrain that has previously been associated with drug cravings and hunger. . Not only was it similar to the signal produced when subjects saw images of food after the fast, but the amount of activation correlated with the intensity of the reported desire. The researchers also found that after their stay in the isolation room, people who reported being chronically alone in previous months had lower urges for contact than people used to more interaction.
“For people who reported that their lives were really filled with satisfying social interactions, this intervention had a greater effect on their brains and on their self-reports,” says Saxe.
Researchers now hope to explore questions such as how social isolation affects behavior, whether virtual experiences such as video calling help alleviate urges for contact, and how isolation affects different age groups.