What are mirror neurons

Mirror neurons are impulse-conducting cells in the brain that activate not only when a subject does something but also when the subject merely observes someone else do the same thing. Since mirror neurons fire in response to observing an action, mirroring the brain state of another, they enable emotional empathy and rapid learning through imitation. Both of these responsive behaviors are examples of entrainment, the syncing up with another person, which is especially common with facial expressions and rhythmic motions. This happens subliminally most of the time, but a commonplace example is when someone laughs or cries and you find yourself laughing or crying with them without yet knowing why. The brain is wired to respond that way.

Mirror neurons were first observed in macaque monkeys in 1992 by Italian researchers (Rizzolatti et al.) but have since been confirmed in human brains in 2007. V.S. Ramachandran is among the leading researchers in this area of neuroanatomy.