I just started reading the neuroscience book Incognito, by David Eagleman, and came across the passage below. It reminded me of the feeling that i experienced when i discovered how easy it was for me to play in octaves on a Hayden duet with a mirrored left side in comparison to one with the conventional arrangement:   "To demonstrate the interference of consciousness as a party trick, hand a friend two dry erase markers -- one in each hand -- and ask her to sign her name with her right hand a