You’re home, catching up on an episode of “Bloodline” on Netflix. Sissy Spacek reaches out to stroke that handsome Kyle Chandler’s hand. The vast majority of people simply view that scene, but for two out of 100 people, they may have the sensation that their own hand is being touched. Wild, huh?
It’s called mirror-touch synesthesia, where people can view someone else being touched and experience a sensation of touch, pain and other physical input. A new study published in the journal Cortex examined the phenomenon more closely.
The study was conducted in the University of Delaware’s Department of Psychological and Brain Sciences. Over the course of several years, their researchers tested a pool of undergrads. They sat at a table, with their palms facing up or down, and viewed videos that showed someone else’s hand being touched—either on the surface or palm, index finger or ring finger. The students were asked if they felt anything, where, and how strong the sensation was. Some had phantom sensations, and they most closely matched when the study participant’s hand matched the hand depicted in the video. Of the 2,351 students tested, 45 turned out to have mirror-touch synesthesia,
Assistant professor Jared Medina wrote, “Some of the students in our study didn't know that what they were experiencing was different from the rest of the population, and it blew their minds. But if you have mirror-touch synesthesia, there’s nothing wrong with you. It’s just an interesting difference, like being double-jointed.”
Scientists know that people with mirror-touch synesthesia have brains that map tactile data differently, but don’t know why. They may have hyperactive networks in areas of their brains dedicated to neurons associated with touch. Other forms of synesthesia exist, such as people who hear music as having a distinctive color—Billy Joel and Stevie Wonder are famous examples—or see words in color. (Check out our story on people who Smell in Technicolor. ) But the cool takeaway is that we all experience the world a little differently—and that this is a mysterious and wonderful thing.