First evidence of mirror-like activity found in individual human neurons

In the early 1990s, researchers studying nonhuman primates discovered a population of brain cells they called "mirror neurons." These specialized brain cells fired when the animal performed an action and also when the animal observed another performing that same action. The discovery of mirror neurons seemed to support the idea that we understand the actions of others by internally simulating them in our own minds. But if that were the case, how would anyone be able to imagine doing something they had never done themselves? How could anyone understand Superman flying, for example, when no human has ever been able to fly?