Independent.UK: Everyone knows that sleep is key to our physical and mental wellbeing, however, a new study claims that getting sufficient shut-eye is also fundamental for maintaining a thriving social life. According to researchers at the University of California, Berkeley, sleep-deprived individuals can suffer from more than just under-eye bags and are more likely to feel lonelier and less inclined to interact with others than their well-rested pals.The findings, published in the journal Nature, revealed that those who have not slept enough may also appear more socially unattractive to others, exacerbating existing feelings of social isolation. The researchers conducted the study via a series of experiments using fMRI brain imaging, surveys, videotaped stimulations and standardised loneliness measures. In the first experiment, they examined the brain scans of 18 healthy, young adults after both sleepless nights and well-rested ones.Participants had their scans analysed while they watched video clips of strangers approaching them; when they felt someone had gotten too close, they could push a button to stop the video. The study’s authors found that people experienced strong social repulsion activity in the brain during the experiment when they were sleep-deprived and reacted in a way that is akin to feeling like their personal space is being invaded or that they are in a potentially threatening situation.In a subsequent experiment, the researchers found that the part of the brain which encourages social interaction was significantly stunted in those who were sleep-deprived. In another part of the study, more than 1,000 people were recruited online via Amazon’s Mechanical Turk marketplace to watch clips of the participants talking to one another about commonplace activities.They were asked to rate how lonely each of them appeared, unaware that some were sleep deprived.Those who were in a sleep-deprived state ranked as lonelier and less socially desirable by the observers.