J. Neuroscience has a "Journal Club" article on M1 activity during action perception. I haven't looked at it in detail yet, but you can check it out here:
Action-Coding Neurons in Primary Motor Cortex: Making Sense of M1 Activity
during Action Perception
Jean-Francois Lepage, Melissa Lortie, and Francois Champoux
J. Neurosci. 2008;28 1995-1996
Btw, my teaching duties next quarter include a grad course on mirror neurons. I'll simulcast that course here as well. Should be fun.
P.s., still intend to post comments on the SD readings, but gotta get a grant resubmitted first!