Neurons are not associated one-on-one with a specific function. There is no such thing as a mirror neuron or the mirror system, just as there is no Jennifer Aniston neuron or neurons for a particular emotion or a particular movement. Just as a swallow in a flock is not a “flock swallow”, a neuron which is involved in seeing somebody else perform one of our actions is not a mirror neuron.
The placebo effect doesn’t exist
Depression lifts with placebo pills, joint pain disappears after a placebo operation. Changes in the brain can be observed after the use of a placebo. How do such effects of sham treatment come about? Placebos do have effects. But THE placebo effect does not exist.