Mental rotation (shepard and metzler: mental rotation: ability to imagine objects changing their orientation. Methods: present ps with pairs of either identical (can be rotated in correspondence) or mirrored image of 3d objects made of cubes, are they the same object or different, measured rt. If spatial representation, greater degree of rotation will increase rt. If propositional representation, all rotations will take the same amount of rt. Results: spatial representation, reaction time varied as a function of degree of rotation. Conclusions: mental rotation is continuous and supports spatial representation. In one of his early experiments, kosslyn asked subjects to memorize a picture of an object, i. e. a boat, and then to create an image of that object in their mind and to focus on one part, Is there a way to resolve the imagery debate: yes, by investigating how the brain responds to visual imagery.