Researchers have been trying to understand the impact of loneliness on our bodies and brains for decades. As containment measures continue to appear here and there due to the current crisis, we must keep in mind that social contact is a real need of our brain.
Scientists didn't wait for the recent Covid-19 pandemic to focus on the effects of loneliness on the human body and brain. On March 29, 2021, Wired magazine evoked Donald Hebb (1904-1985), a Canadian psychologist who conducted an experiment in the 1950s. He had paid students so that they stay alone in a small space. This experiment was particularly extreme, as the subjects had their hands in cardboard tubes, their ears covered by a cushion, and their eyes obstructed by opaque goggles. Donald Hebb then observed a deterioration of mental faculties.
So indeed, we humans very rarely have to deal with such intense social isolation. However, several studies have already shown that in everyday life, the simple fact of being alone can harm physical and mental health . Some studies had pointed out the advantage of having strong social ties in everyday life. Others had established links between loneliness and depression, or even the onset of cardiovascular disease.
Despite all this research, it took until last year for researchers to actually observe the effects of social isolation on our brain . According to the study published in the journal Nature Neuroscience on December 23, 2020 by a team from the Massachusetts Institute of Technology (MIT), social contact is a vital need for our brain.
For the purposes of their study, the researchers recruited four volunteers. They were asked to abandon their smartphones, computers and other tablets and then stay in one room for about ten hours . In order to keep busy, participants could only write or do puzzles. At the end of the allotted time, the leaders of the study carried out functional MRIs on these same volunteers, while showing them images.
When it came to images relating to a social relationship, their brains "lit up" in areas related to cravings . This illumination was as intense as showing images of appetizing food to hungry people. However, these areas contain many dopaminergic neurons, the latter defining our motivations and other expectations in the face of the outside world. The thing is, these neurons fire when our brains anticipate positive activity , such as having social contact or feeding. The worry lies in the lack of satisfaction, making our brains kind of "starve" due to the lack of social interactions (or food).
For the leaders of the study, this principle could explain the harmful consequences of isolation in the long term. It makes sense that our brain has to adapt, which in itself is not something bad. On the other hand, this ability to adapt is not made to last in the long term and that is precisely where the problem lies.
