Look at something. Close your eyes. Retain the image. Try to "look" at parts of the image. Focus on parts of the image. Then... change them. No, that apple was green, not red. You know what a red apple looks like, you know what a green apple looks like; Focus on the overall feel of the rest of the image while the apple is different.
It's not easy, it's a trained skill, though I guess one that's pretty easy to acquire accidentally by daydreaming and doing art. I think I actually trained myself out of it as part of "safety" training; I stopped relying on mental models of many things and started forming mental models of the checklists to get them into that state.
