> "Obviously a skilled illustrator, painter or sculptor is going to be better at visualizing imagery than someone who doesn't do those things. If that's the case, just thinking about images a lot makes you better at visualizing images."

What you say seems intuitive, but (and this is just a digression) I also think being able to imagine something and recreate it in the real world are two separate (though related) skills. Imagining something means the brain only has to, say, recreate some of the "effects" of incoming sensory data. On the other hand, creating something in the real world as an artist does, whether with paint or a musical instrument, involves a feedback loop. The artist must identify the real-world color or proportion or sound he imagines, which is a skill in itself, then must participate in a feedback loop of: percieve what you just created, compare to imagined goal (which may now change), edit creation. This requires both the mental skill to do so, plus the motor skill to pull it off (as far as the artistic creation depends on muscle movements).

In this way, someone could have a vivid "mind's eye" but be a lousy artist. Or remember musical structures (such as chord progressions) without being able to identify or recreate them (at least not without a ton of trial and error as the skill is developed).