New research shows that a molecule in the Szechuan pepper, Hydroxy-alpha-sanshool, excites a certain type of tactile sensor in our skin in a way that feels like the sensors have been vibrated very quickly. University College London researchers explored this strange phenomena by brushing volunteers' lips with both ground Szechuan peppers and later a vibrating metal tool to match the level of numbness caused by the pepper. By identifying the frequency of the numbing sensation, the scientists determined that the high-sensitivity Meissner receptors in the skin were the ones fired up by the Szechuan peppers.
"Why Szechuan Peppers Make Your Lips Go Numb" (Smithsonian)
David Pescovitz is Boing Boing's co-editor/managing partner. He's also a research director at Institute for the Future. On Instagram, he's @pesco.