What is the logic behind visualization meditation

I have practiced meditation for the better part of a decade now. I wouldn't call myself a Buddhist, but that's immaterial. I've experienced and practiced many kinds of meditation (energy, dream, mindfulness), and all of the meditations I have practiced I have a logic for. I can understand the goal of the meditation and why the meditation works. One meditation that I've always been troubled by is visualization meditation. The type where repeatedly visualizing a very complex scene leads to certain goals. How is it that by visualizing a certain scene I enact unique changes in my psyche? Obviously there are many different flavors, but recently every path I turn to has resulted in some kind of visualization meditation and I quite honestly doubt the very fundamentals of such a meditation. When I have such a strong doubt I certainly won't be able to practice effectively. Are there any resources on this subject?