This is a half-formed thought, but if you are blind, how would you perceive space? You can feel against a wall, but you will only be correlating time with locomotion (how long it takes to move your hand against a wall at a certain force) to create space. Spatial reasoning becomes temporal reasoning. (Ignore for the moment you can directionally locate by hearing). It makes this result even more fascinating to me that they are biologically linked to the same part of the brain, rather than one part compensating for another.