"Here the exciting development has to do with the discovery of "mirror neurons" in the primate brain. These neurons are activated when an individual watches another individual perform an action or display an emotion, thus replicating the experience in its own brain. "Mirror neurons," writes Marco Iacoboni, "gracefully solve the problem of other minds, which is fundamentally a problem of having access to the mind of other people." Even for non-specialists, The Primate Mind offers the excitement of seeing science begin to offer concrete answers to such fundamental and ancient human questions."
--From Adam Kirsch's review of The Primate Mind: Built to Connect with Other Minds, edited by Frans B. M. De Waal and Pier Fransesco Ferrari.
As V.S. Ramachandran explains in a now famous article, “The Neurology of Self Awareness�?: “The discovery of mirror neurons was made by G. Rizzolati, V. Gallase and I. Iaccoboni while recording from the brains of monkeys performing certain goal-directed voluntary actions. For instance when the monkey reached for a peanut a certain neuron in its pre motor cortex (in the frontal lobes) would fire. Another neuron would fire when the monkey pushed a button, a third neuron when he pulled a lever. The existence of such Command neurons that control voluntary movements has been known for decades. Amazingly, a subset of these neurons had an additional peculiar property. The neuron fired not only (say) when the monkey reached for a peanut but also when it watched another monkey reach for a peanut!�?
“These were dubbed "mirror neurons‟ or "monkey-see-monkey-do‟ neurons. This was an extraordinary observation because it implies that the neuron (or more accurately, the network which it is part of) was not only generating a highly specific command ("reach for the nut‟) but was capable of adopting another monkey's point of view. It was doing a sort of internal virtual reality simulation of the other monkeys action in order to figure out what he was "up to‟. It was, in short, a "mind-reading‟ neuron.�?