The condition is called mirror-touch synesthesia, and it has aroused significant interest among neuroscientists in recent years because it appears to be an extreme form of a basic human trait.
In all of us, mirror neurons in the premotor cortex and other areas of the brain activate when we watch someone else’s behaviors and actions. Our brains map the regions of the body where we see someone else caressed, jabbed, or whacked, and they mimic just a shade of that feeling on the same spots on our own bodies. For mirror-touch synesthetes like Salinas, that mental simulacrum is so strong that it crosses a threshold into near-tactile sensation, sometimes indistinguishable from one’s own.
Neuroscientists regard the condition as a state of “heightened empathic ability.”