It’s called ASMR, and boy does it feel good.

The triggers vary. For me, it’s watching a stranger concentrate on an insignificant task. Doesn’t matter the task — could be taking photos, positioning a lamp, drawing a picture, whatever. What matters is that a) I don’t know the person and b) they’re completely absorbed, oblivious to any onlookers.

The sensation starts at the top of my scalp and drifts down the back of my head, covering my neck and shoulders but descending no farther. It’s a mild, almost sub-electric tingling. Completely pleasurable, completely non-sexual and completely prone to interruption.

Ever had it? If you have, you know exactly what I’m talking about. If not, it’s tough to explain.

The phenomenon is a real thing, and it’s called Autonomous Sensory Meridian Response (ASMR). Most people describe its effects as I have: tingling that begins on the head and travels down the back. Some experience ASMR (which my non-susceptible friends have dubbed Ass-Mar) as a whole-body experience. Some use it to induce sleep. Others just like the way it feels.

The only scientific study of ASMR so far was conducted by Emma L. Barratt and Nick J. Davis of Swansea University in the UK, who narrow down the triggers to four main categories:

  1. Whispering: A very common trigger—and highly accessible, thanks to a host of YouTube channels dedicated to ASMR-inducing whispers.
  2. Personal attention: Things like massages, haircuts and even doctor/dentist appointments can trigger ASMR.
  3. Crisp sounds: Things like crinkling chip bags work for some people.
  4. Slow movements: I assume that this is where my trigger fits in. Slow, methodical (and most importantly — at least for me — unselfconscious) movements will unleash a beautiful static-y wave.

Barratt and Davis’s study found that 59% of people who experienced ASMR said they knew of no family members who experienced it. (They do suggest that the stigma surrounding the ‘strangeness’ of the thing might prevent people from talking openly about it.) Nobody’s sure where it comes from or why some people experience it and some don’t.

I grew up thinking of ASMR as “the tinglies,” and assumed they were a universal phenomenon. It wasn’t until I mentioned it to my older sister (“Know the tinglies you get when watching someone focus?”) and her subsequent look of derision that I realized I might be a weirdo.

But if you’re like me, don’t worry: We aren’t alone.