Emotion and mirror neurons (2)

Professor Christian Keysers discusses evidence that mirror neuron systems are necessary for processing emotions.

It’s very difficult to actually know what systems are really necessary for a task like social cognition, and the reason is quite simple; imagine you have a car, and there’s a stoplight at the back. Each time you stop or you decelerate this light goes on. But if I were to ask you is the light actually necessary for slowing down the car, if you wouldn’t know about cars a very simple way to find out (especially if it’s a friend’s car) you could take a hammer, break the red light in the back and see whether the car can still decelerate. If the car can still decelerate it wasn’t necessary, if it stops decelerating you know that the light was necessary. Now obviously in humans that’s a lot harder to do, because if we localize an area to contain mirror neurons, we can’t just take a hammer and break that area and see if people will still socialize. So quite honestly the evidence we have is relatively meager; one thing we do know is that patients with lesions in the insula lose two faculties; one is the faculty to feel disgust themselves, so you can give them a glass of rotten milk and they’ll drink it quite happily, and the other thing is if you show them a photo of a happy person they can tell you the person is happy, show them a photo of a sad person they can tell you that person is sad. But if you show them a picture of a disgusted person, a photo of someone having the emotion they can no longer have, they are incapable of telling you that person is disgusted. So from that we seem to see that mirror [neuron] systems for certain emotions for instance, are really necessary to understand this emotion in other people.