Brain Damage?

I hope Siena's brain doesn't suffer from doing this: she loves to throw her head back and hit it hard against the chair. Masochist! The video doesn't do it justice, but I'll put it on anyway. Be sure to look for Siena's "trademarks" which include: her tongue moving fast in every direction, the comb which can be found at all times in her grasp, the crazy hair that I still have to work up a nerve to cut, random bouts of giggling, and the head banging, of course.