Poor sleep triggers viral loneliness and social rejection: Lack of sleep generates social anxiety that infects those around us -- ScienceDailyNotably, 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 added. "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.