Aphantasia
Can you picture a clear image of an object or a person in your head when thinking of them?
For many, the answer is yes. They can visualize what, for example, a cat
looks like. Some can create a clearer image and hold it longer in their
mind's eye than others. People with aphantasia lack this ability of
visualisation.
Aphantasia is the inability to voluntarily
create mental images in one's mind. Aphantasiacs cannot create visions
of things and people around them or picture memories or thoughts in
their head.