The study, which was published in the journal ‘Current Biology’, also suggests that people might be able to train themselves to improve their social perception and become less lonely.
The researchers scanned the brains of 108 healthy adults and gave them several different tests to see how differences in loneliness might be reflected in the structure of the brain regions associated with social processes. Their level of loneliness was self-reported and measured using a questionnaire.
When looking at full brain scans, the team saw that lonely individuals have less grey matter in an area of the brain that has been implicated in basic social perception, the left posterior superior temporal sulcus (pSTS). This suggests that loneliness might be associated with difficulty in processing social cues.
Dr Ryota Kanai from the UCL Institute of Cognitive Neuroscience, who led the study, said: “Before conducting the research, we might have expected to find a link between lonely people and the part of the brain related to emotions and anxiety, but instead we found a link between loneliness and the amount of grey matter in the part of the brain involved in basic social perception.”
To gauge social perception, participants were presented with three different faces on a screen and asked to judge which face had misaligned eyes and whether they were looking either right or left. Lonely people found it much harder to identify which way the eyes were looking, confirming the link between loneliness, the size of the pSTS and the perception of eye gaze.
“From the study we can’t tell if loneliness is something hardwired or environmental,” said coauthor Dr Bahador Bahrami, also from the UCL Institute of Cognitive Neuroscience. “But one possibility is that people who are poor at reading social cues may experience difficulty in developing social relationships, leading to social isolation and loneliness.”
Dr Kanai added: “The idea of training is one way to address this issue, as by maybe using a smartphone app to improve people’s basic social perception (such as eye gaze), hopefully we can help them to lead less lonely lives.”
Image: ‘Lonely’, by Vermario on Flickr.
Kanai R et al. Brain structure links loneliness to social perception.
Curr Biol 2012;22(20):1975-9.