Via Greg Gilmer:
This will confuse your mind and you will keep you trying it over and over again to see if you can outsmart your foot. It is pre-programmed in your brain! 1. While sitting at your desk in front of your computer, lift your right foot off the floor and make clockwise circles. 2. Now, while doing this, draw the number ‘6’ in the air with your right hand. Your foot will change direction. I told you so!