Autonomous sensory meridian response (ASMR) is a calming, pleasurable feeling often accompanied by a tingling sensation. This tingle is said to originate in a person’s head and spread to the spine (and sometimes the limbs) in response to stimulation. The stimuli that trigger ASMR vary from person to person. Some of the most common ones include whispers, white noise, lip smacking, having a person’s complete attention (as in having one’s hair cut by a hairdresser), as well as brushing, chewing, tapping, scratching, whispering, and crinkling.

Aside from the pleasurable sensation that ASMR offers there are a range of other benefits. Many intentional ASMR videos are essentially forms of guided meditations, meditating regularly has been shown to reduce stress levels and aid concentration among many other things. For a lot of people ASMR is a gateway to developing an ongoing meditative practice. 
Like those who posted before me, I have experienced ASMR for many years. My earliest memories are around the second grade. In my second grade class, we were required to read with partners; however, I was a more advanced reader and would allow my partner to read the entire time if he/she wanted. I would experience intense tingling around the crown of my head listening to him/her read, but I would also experience very intense tingling in the frontal lobe region watching him/her turn the book pages. Around the same time, I would intentionally watch Bob Ross on PBS (like others have mentioned) to take a nap due to the same tingling sensation and calm/relaxation he induced.
While little scientific research has been conducted into potential neurobiological correlates to the perceptual phenomenon known as 'autonomous sensory meridian response' (ASMR), with a consequent dearth of data with which to either explain or refute its physical nature, there is voluminous anecdotal literature comprising personal commentary and intimate disclosure of subjective experiences distributed across forums, blogs, and YouTube comments by hundreds of thousands of people. Within this literature, in addition to the original consensus that ASMR is euphoric but non-sexual in nature, a further point of continued majority agreement within the community of those who experience it is that they fall into two broad categories of subjects.

The uncharted territory isn’t what people experience, Richard says, but how (some people are triggered through their own thoughts and memories; others through external sights, sounds or touch) and why. To help find answers, Allen and Richard’s team launched its first rudimentary ASMR research survey last month. It received more than 4,000 responses within the first 10 days.
I’m not sure if I have asmr or not but I’ve never felt this feeling or some thing similar to this at all but I felt it 8times while playing battlefield hardline today but I know it not from that. When it happens I get a small tingly sensation and it’s warm and fuzzey and feels nice but not strong enough to make me really relaxed. I don’t know why but when ever I feel this and close my eyes and relax my muscles, it seems to last a little longer then if I move around. I know this isn’t frission because I don’t get energized by it but it makes me want to sleep.also I have aspergers, ADD and ADHD. I’m not sure if this makes it so I can or can’t feel this or not. can some one please reply?
In 2012, Steven Novella, a neurologist at the Yale University School of Medicine wrote a blog post about ASMR, asking “the most basic question—is it real? In this case I don’t think there is a definitive answer, but I am inclined to believe that it is… It’s similar to migraine headaches—we know they exist as a syndrome primarily because many different people report the same constellation of symptoms and natural history.” He goes on to speculate as to what ASMR could be—possibly small seizures, or “just a way of activating the pleasure response.”
Over at Shenandoah University in Winchester, Va., Craig Richard, a professor of biopharmaceutical sciences, runs the clearinghouse website ASMR University, where he interviews people who’ve studied the phenomenon and blogs about ASMR in the news. Richard himself reports experiencing ASMR; nevertheless, he says scientific skepticism is warranted until more studies are published. To that end, Richard and two other researchers, Allen and a graduate student, have been conducting an online survey that he says so far includes 20,000 people across over 100 countries, almost all of them “tingleheads.”
In a 2012 blog post, Steven Novella, an academic clinical neurologist at Yale University School of Medicine, compared ASMR to migraine headaches — “We know they exist as a syndrome primarily because many different people report the same constellation of symptoms and natural history,” he wrote — and theorized that ASMR could even be a type of “pleasurable” seizure.
I can trigger my ASMR at any time and it helps me gather my thoughts and calm down easily. It is weird to do, I have just recently found out about it and I was really strange knowing that not everyone could just do it anytime, sometimes or not at all so this is so strange before I found this out I thought I was just giving my self goosebumps just without the bumps so those are my feelings I just had to get out of my system.

Among the category of intentional ASMR videos that simulate the provision of personal attention is a subcategory of those specifically depicting the "ASMRtist" providing clinical or medical services, including routine general medical examinations. The creators of these videos make no claims to the reality of what is depicted, and the viewer is intended to be aware that they are watching and listening to a simulation, performed by an actor. Nonetheless, many subjects attribute therapeutic outcomes to these and other categories of intentional ASMR videos, and there are voluminous anecdotal reports of their effectiveness in inducing sleep for those susceptible to insomnia, and assuaging a range of symptoms including those associated with depression, anxiety, and panic attacks.[17][18][19]