For 20 minutes, soft-spoken Maria instructs YouTube viewers on the art of folding towels. Only her hands, a glossy black table, and a towel are visible throughout the video, which has more than 1.3 million views. The video isn't popular because a rash of folks are dying to learn how to fold towels. Instead, it's because an increasing number of people report experiencing autonomous sensory meridian response (ASMR), a whole body tingling that listening to soft, monotone voices can trigger.

ASMR is a self-reported neurological experience that causes people who have it to experience "brain orgasms,” a tingling, pleasurable sensation that begins at the head or neck and works its way throughout the body. The most common triggers of this sensation include educational videos, having one’s hair cut, feeling empathetic, enjoying music or art, listening to slow, enunciated speech, and experiencing close personal contact. In the world of ASMR, Bob Ross and NPR hosts constitute porn. People with ASMR say it feels pleasant and loads of people watch and re-watch seemingly dull videos to spark an ASMR episode.

While people with ASMR quite passionately agree that the phenomenon exists, science isn't so sure. There are zero articles about autonomous sensory meridian response on PubMed, the clearinghouse for peer-reviewed scholarly medical articles, and many doctors think the experience is bunk. But Steve Novella, director of general neurology at Yale School of Medicine, says it likely exists, but it just hasn't been classified yet. He writes on NeuroLogical Blog:

I always start my investigations of such phenomena by 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. There are a number of people who seem to have independently (that is always the key, but it is a recent enough phenomenon that this appears to be true) experienced and described the same syndrome with some fairly specific details. In this way 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 hypothesizes that people with ASMR might experience little seizures sparked by auditory cues. (Apparently, some seizures feel good.) But it could also be that people process pleasure and pain differently. And for some, pleasure feels like a full body orgasm, while others have less of a visceral response. “Or, ASMR could just be a way of activating the pleasure response … all of our human brains are not clones or copy cats, but vary in every possible way they can vary,” Novella writes.

And he urges more research. Most brain imaging techniques could easily see what occurs in the brain, providing scientists with a better understanding as to why brain orgasms occur for some when Ira Glass speaks on This American Life or someone has her hair washed at the salon.