A good test for me was this: ask someone to close their eyes and visualize an apple. Ask them what they experience. Some only 'see' the concept. Some only outli

A good test for me was this: ask someone to close their eyes and visualize an apple. Ask them what they experience. Some only 'see' the concept. Some only outlines. Some see black and white. Some see colors. Some see very specific things, like the brand. Some experience an entire scene, with smells and all.