People who are lonely have less grey matter in an area of the brain associated with decoding eye gaze and other social cues, according to researchers from University College London.
The study also suggests that lonely people can be taught how to improve their social perception and, in turn, feel less lonely.
“What we’ve found is the neurobiological basis for loneliness,” said lead author Ryota Kanai, Ph.D., of the UCL Institute of Cognitive Neuroscience.
“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.”
The team set out to see whether differences in loneliness were reflected in the structure of brain regions associated with social processes. The researchers scanned the brains of 108 healthy adults and gave them a variety of tests. Loneliness was self-reported and measured with a UCLA loneliness scale questionnaire.
The brain scans revealed that lonely individuals had less grey matter in the left posterior superior temporal sulcus (pSTS) — an area associated with basic social perception. This suggests that loneliness is linked to difficulties in processing social cues.
“The pSTS plays a really important role in social perception, as it’s the initial step of understanding other people,” said Kanai. “Therefore the fact that lonely people have less grey matter in their pSTS is likely to be the reason why they have poorer perception skills.”
In order to gauge social perception, participants viewed three different faces on a screen and were asked to judge which face had misaligned eyes and whether they were looking either right or left.
The study found that lonely people had a much harder time identifying 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 co-author Bahador Bahrami, Ph.D., of 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.”
Researchers suggest social perception training as a way to combat feelings of loneliness.
“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,” Kanai said.
The research is published in the journal Current Biology.
Source: University College London