Kosslyn asked subjects if frogs have lips and a stubby tail. what did the subjects report?

The answer to this question is They visualized a frog, starting with the face ("no lips") and mentally rotated the image to look for the stubby tail.
This findings indicates that humans have the capability to form a mental space in our mind in a 3 dimensional form which really contributed to our cognitive imagery capability.

Ghana, first of the great medieval trading empires of western africa (fl. 7th–13th century). it was situated between the sahara and the headwaters of the sénégal and niger rivers, in an area that now comprises southeastern mauritania and part of mali.