New research shows that feelings of loneliness are linked to fundamental differences in the ways our brains are wired – affecting our perspective on friends, acquaintances, and people we've never met.

While it's only a small study, with much of the world currently in lockdown or practising social distancing, it's a timely insight into the impacts of feeling lonely.

Through a detailed analysis of fMRI scans, researchers showed that the lonelier someone is, the more likely they are to feel that friends and acquaintances are distant, and these social connections all tend to blur into one whole as far as the brain goes.

While we know that close social connections are good for our health, scientists don't fully understand how these connections map themselves out in the brain.

These new findings could help fill in some of the gaps in our knowledge – and maybe lead to ways to better manage feelings of loneliness and isolation.

"The social brain apparently maintains information about broad social categories as well as closeness to the self," report the researchers in their published paper. "Moreover, these results point to the possibility that feelings of chronic social disconnection may be mirrored by a 'lonelier' neural self-representation."

The study focussed in on the brain's medial prefrontal cortex (MPFC), where our minds keep a map of our social circles, based on closeness. People who feel lonelier tend to feel a gap between themselves and others, which is reflected in MPFC activity.

Participants in the tests were asked to concentrate on 16 different people: themselves, five close friends or family, five acquaintances, and five celebrities. They reported on their own feelings of loneliness and how close they felt to each person while their brains were being monitored by researchers.

When thinking about close contacts, the MPFC scans showed the volunteers' brain activity was similar to how it was when they were thinking about themselves. Social closeness seems to be reflected in similar brain activity for considering both the self and others.

That similarity was less evident for people who described themselves as lonelier – the difference between the patterns for the self and others was greater.

Not only that, but the patterns for close contacts became more like those for acquaintances and celebrities, with people outside the self all blurring into one.

Bear in mind that as well as involving only a small sample of people, the study doesn't show exactly how this self-other gap in the brain's thinking happens – is it caused by feelings of loneliness, or does loneliness come about as a result of it? This is one of the areas that future studies could look into.

For now the study offers some much-needed detail on how social connections map to brain activity. It also emphasises the importance of what the researchers call "weaker ties" beyond our handful of best friends – the way that friends-of-friends, acquaintances, and those that we don't know all that well contribute to our sense of wellbeing.

In these times of social distancing, the absence of those weaker ties with people who are just outside our closest friends may be more important to our mental health than we thought – many of us are having much less contact with our wider social circles right now.

"We're missing out on a lot of that," psychologist Andrea Courtney, from Stanford University, told CNN. "So that could be a part of why we're seeing increases in loneliness."

The research has been published in JNeurosci.