The feeling of longing experienced during forced social isolation shares a neural basis with the food cravings we feel when hungry, according to research from the US.
Researchers at the renowned Massachusetts Institute of Technology (MIT) used functional magnetic resonance imaging (MRI) to measure neural responses evoked by food and social cues after participants (n=40) experienced 10 hours of mandated fasting or total social isolation.
After isolation, people felt lonely and craved social interaction. Midbrain regions showed selective activation to food cues after fasting and to social cues after isolation. These responses were correlated with self-reported craving.
In contrast, striatal and cortical regions differentiated between craving food and craving social interaction.
Across deprivation sessions, deprivation narrowed and focused the brain’s motivational responses to the deprived target.
After one day of total isolation, the sight of people having fun together activated the same brain region that lit up when someone who had not eaten all day saw a picture of a plate of cheesy pasta.
People's responses to isolation varied depending on their normal levels of loneliness. People who reported feeling chronically isolated months before the study was done showed weaker cravings for social interaction after the 10-hour isolation period than people who reported a richer social life.