I can do it. I can also move my eyebrows, nostrils, and ears separately. I think it’s a side effect of meditation. I call them “Stupid Buddhist Tricks,” because they occur entirely without effort through biofeedback. There’s a simple experiment to demonstrate the phenomenon:
Get a straw from a straw broom and impale it edge-on on a flat tack. Lie down on your back and balance the tack on your breastbone. The end of the straw will now move visibly each time your heart beats. Now just watch the straw for about an hour. At this point, through biofeedback, you will be able to take control of your heart and make it slow down or speed up simply by desiring it to do so.
All of this occurs because connections in the brain run in both directions. When you feel a rush of endorphins in your brain, you smile to express pleasure; because of this connection, we can also induce the brain to produce endorphins by consciously smiling. Through meditation and intense awareness of your body, you’re doing exactly the same thing as when you watch the vibrating end of the straw: you begin becoming consciously aware of each of the individual nerve signals which make up the cascade of complex signals we normally use to move our bodies autonomically.