http://www.newscientist.com/article/mg20427370.500-how-our-brains-build-social-worlds.html?full=true
How can such behaviour be explained in terms of neuroscience? We think that two people performing together in this way are best described as a single, complex system rather than as two systems interacting. We also believe the same kinds of description should be applied generally to the brain activity that occurs when two people interact, because their brains also become a single complex system.