Professor Christian Keysers discusses experiments associating mirror neurons with experiencing and witnessing emotion.
In terms of emotions what we need to be able to see whether we have a mirror system or something like that, are experiments in which we would take an individual, put them in the scanner, make him experience an emotion and see if that activates the same areas as if the person sees someone else have a similar emotion. Now what has slowed down this kind of research is that it’s quite difficult to do for a lot of emotions; I could take you and put you in the scanner and ask you to be happy for ten seconds, but that’s just not going to work. And because of that the one emotion that we really know we have a mechanism similar to actions is for the emotion of disgust, and that’s because it’s very easy to put someone into the scanner and for instance give him a few droplets of something that is really disgusting to taste. With that we can see the brain areas involved with feeling the emotion, and then we do see that seeing someone else’s disgust seems to recruit the exact same neural substrate.