Heck, think about an RPG that focused on internal monologues that required you to describe them in terms of what they looked like.

GM: “So, Sally has just heard about the chaplain’s death. What’s she thinking?”

Player: “Her inner landscape shifts from misty blue to a stormy blue-grey, swirling with wisps of black that flow in chaotically and then build until they form a funnel of oily tears.”