New Delhi: Sleep-deprived people feel lonelier and less inclined to engage with others, avoiding close contact in much the same way as people with social anxiety, according to a new study. Worse still, that alienating vibe makes sleep-deprived individuals more socially unattractive to others. Moreover, even well-rested people feel lonely after just a brief encounter with a sleep-deprived person, triggering a viral contagion of social isolation.
The findings are the first to show a two-way relationship between sleep loss and becoming socially isolated, shedding new light on a global loneliness epidemic. “We humans are a social species. Yet sleep deprivation can turn us into social lepers,” says senior author Matthew Walker, a professor of psychology and neuroscience at the University of California, Berkeley.
Notably, researchers found that brain scans of sleep-deprived people as they viewed video clips of strangers walking toward them showed powerful social repulsion activity in neural networks that are typically activated when humans feel their personal space is being invaded.
Sleep loss also blunted activity in brain regions that normally encourage social engagement. “The less sleep you get, the less you want to socially interact. In turn, other people perceive you as more socially repulsive, further increasing the grave social-isolation impact of sleep loss,” Walker adds.
“That vicious cycle may be a significant contributing factor to the public health crisis that is loneliness.” National surveys suggest that nearly half of Americans report feeling lonely or left out. Furthermore, loneliness has been found to increase one’s risk of mortality by more than 45 percent — double the mortality risk associated with obesity.
To gauge the social effects of poor sleep, Walker and Ben Simon conducted a series of intricate experiments using such tools as fMRI brain imaging, standardised loneliness measures, videotaped simulations, and surveys via Amazon’s Mechanical Turk online marketplace.
First, researchers tested the social and neural responses of 18 healthy young adults following a normal night’s sleep and a sleepless night. The participants viewed video clips of individuals with neutral expressions walking toward them. When the person on the video got too close, they pushed a button to stop the video, which recorded how close they allowed the person to get.
As predicted, sleep-deprived participants kept the approaching person at a significantly greater distance away—between 18 and 60 percent further back—than when they had been well-rested. Researchers also scanned participants’ brains as they watched the videos of individuals approaching them.
In sleep-deprived brains, researchers found heightened activity in a neural circuit known as the “near space network,” which activates when the brain perceives potential incoming human threats.
The observers were unaware that the subjects had been deprived of sleep and rated each of them based on how lonely they appeared, and whether they would want to interact socially with them. Time and again, they rated study participants in the sleep-deprived state as lonelier and less socially desirable.
