Mirror Neuron Death March

Above image: Jim Peters almost wins the marathon Vancouver, 7 August 1954, with mirror neurons by Rizzolatti & Craighero (2004).

Greg Hickok at Talking Brains has a series of posts dismantling the mirror neuron theory of action understanding. Actually, he lets one of the leading researchers in the field, Giacomo Rizzolatti [and his coauthor] dismantle the theory himself in a recent review paper (Rizzolatti & Sinigaglia, 2010). Greg points out the inconsistencies in the NRN article...

So, mirror neurons, those cells that fire during specific actions such as grasping-with-the-hand and while watching the same specific action -- the very cells that got everyone SO excited -- are not involved in action understanding. Rather, according to R&S, action understanding is achieved by cells that do not code for actions at all, but something higher level, goals/intentions.

It's worth noting that R&S directly contradict themselves in the sidebar definition of "Mirror-based action understanding":

The comprehension of an observed action based on the activation of a motor programme in the observer’s brain. p. 265

A motor program presumably controls a specific action, such as grasping-with-the-hand, not an action-independent goal or intention.

...and also the problems with promoting an unfalsifiable theory:

I think the mirror neuron folks have a serious problem on their hands: there is apparently no empirical result that can falsify the theory. If a mirror neuron shows up in an unexpected place, it is a new part of the mirror system. If a mirror neuron's activity dissociates from action understanding, it was not coding understanding at that moment. If damage to the motor system doesn't disrupt understanding, it is because that part of the motor system isn't mirroring.

As another long-time mirror neuron skeptic, I highly recommend this series:

Mirror Neurons - The unfalsifiable theory

Mirror neurons support action understanding -- "from the inside"?

Self-destruction of the mirror neuron theory of action understanding

Reference

Rizzolatti, G. & Sinigaglia, C. (2010). The functional role of the parieto-frontal mirror circuit: interpretations and misinterpretations. Nature Reviews Neuroscience, 11 (4), 264-274.

Everybody in Mirror Neurons!

See Spindle Neurons: The Next New Thing?