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, it must be borne in mind that social contact is a real need of our brains.
Brain and social isolation
Scientists did not wait for the recent Covid-19 pandemic to be interested in the effects of loneliness on the human body and brain. On March 29, 2021, the magazine Wired said Donald Hebb (1904-1985), a Canadian psychologist who carried out an experiment in the 1950s. remain alone in a small space. This experience was particularly extreme, as the subjects had their hands in cardboard tubes, their ears covered by a pillow, and their eyes blocked by opaque glasses. Donald Hebb then observed a deterioration of mental faculties.
So indeed, the humans that we are very rarely have to face 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 the onset of cardiovascular disease.
Despite all this research, it was not until last year that researchers actually observed the effects of social isolation on our brains. According to the study published in the journal Neuroscience of nature on December 23, 2020 by a team from the Massachusetts Institute of Technology (MIT), social contact is a vital need for our brains.
The “hungry” brain in case of lack
For the purposes of their study, the researchers recruited four volunteers. They were told to ditch their smartphones, computers and other tablets and then stay in one room for ten hours. In order to keep busy, participants could only write or do puzzles. At the end of the allotted time, the study leaders have performed functional MRIs on these same volunteers, while showing them pictures.
When it was a question of images relating to a social relation, their brains “lit up” at the level of areas related to desires. This illumination was as intense as showing pictures of appetizing food to hungry people. However, these areas contain many dopaminergic neurons, the latter defining our motivations and other expectations vis-à-vis the outside world. The point is, these neurons activate when our brains anticipates positive activity, like having social contact or eating. The concern lies in the lack of satisfaction, making our brains somehow “hungry” 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 brains have to adapt, which in itself is not bad. On the other hand, this adaptability is not made to last in the long term and this is where the problem lies.