VISUAL MENTAL ROTATION OF POSSIBLE AND IMPOSSIBLE OBJECTS

Participants were tested on two visual mental rotation tasks using thr ee-dimensional ''possible'' and ''impossible'' shapes. Both types of s timuli can be easily encoded by their parts and how they are spatially organized. However, while possible shapes can also be easily encoded as a global image, it is more difficult to encode impossible shapes in such a way. Participants visually rotated both types of stimuli at co mparable rates, reflecting that local representations were used in the process of visual mental rotation.