The ability to trigger feelings of extreme pleasure on-demand is a prospect that's fascinated both scifi writers and scientists for decades. Indeed, the day is coming when we'll be able induce orgasmic-like sensations at the flick of a switch — a prospect with obvious appeal, but with some serious downsides.
It's not exactly a secret that many humans derive pleasure from massages, and previous research has shown other primates enjoy it as well. And now, we've found the first non-primate to use massages to relieve stress: the surgeonfish.
It turns out there is a neurological explanation for why people scratch and cut themselves, and spank each other for pleasure. Inflicting small amounts of physical pain, whether from scratching your skin vigorously or doing something more extreme, deactivates the parts of your brain associated with unpleasant or…