A new study, headed by a team at McGill University, has now identified neurobiological signatures in the brains of lonely people that make them distinct in fundamental ways, based both on variations in the volume of different brain regions, as well as on how those regions communicate with one another across brain networks.
The team examined the magnetic resonance imaging (MRI) data, genetics, and psychological self-assessments of approximately 40,000 middle-aged and older adults who volunteered to have their information included in the U.K. Biobank, an open-access database available to scientists around the world. The investigators then compared the MRI data of participants who reported often feeling lonely with the data from those who did not.
They found several differences in the brains of lonely people. These brain manifestations were centered on the “default network,” a set of brain regions involved in inner thoughts such as reminiscing, future planning, imagining, and thinking about others.
The researchers suggest that the fact that the structure and function of this network are positively associated with loneliness may be because lonely people are more likely to use imagination, memories of the past, or hopes for the future to overcome their social isolation.