Ideasthesia

Ideasthesia is when someone has a special kind of thinking that links sight to sound and shapes to numbers. It's sort of like making a picture in your head. For example, someone who has ideasthesia might hear a song and imagine a certain shape in their head to match it. Or, they might see a number and think of a certain color. It's like having a connection between what you see, hear, or feel and something else.