ASMR stands for Autonomous Sensory Meridian Response, and it's a relaxed, tingling feeling that many people report having as a response to particular stimuli, such as close personal attention, tapping, or whispering. Although its experiencers say they have been aware of the sensation all their lives, it has only recently come together as a public phenomenon thanks to YouTube, where ASMRtists now post thousands of videos that simulate the ASMR experience and help viewers fall asleep when no...