Spatial reasoning is absolutely a form of reasoning (it's right there in the name!). I don't have any references handy, but I've read a few accounts of musical

Spatial reasoning is absolutely a form of reasoning (it's right there in the name!). I don't have any references handy, but I've read a few accounts of musical and math prodigies who have a form of synesthesia that allows them to "see" notes and numbers, respectively, which allows one to reason about abstract concepts as easily as you or I could spot the difference between a circle and a square. Very interesting stuff.