Aphantasia

He could not imagine the apple in his head, the doctor mentioned that happened because he had aphantasia.

Certain people, researchers have discovered, can't summon up mental images—it's as if their mind's eye is blind. This month in the journal Cortex, the condition received a name: aphantasia, based on the Greek word phantasia, which Aristotle used to describe the power that presents visual imagery to our minds. […] If aphantasia is real, it is possible that injury causes some cases while others begin at birth.

That's when I discovered I had aphantasia, the inability to conjure mental images. Little is known about the condition, but its impact on my education led me to wonder about how it might be impacting others. […] [A]phantasia not only impacts people's learning experiences; it also extends into their personal lives. Not being able to visualize means never picturing the faces of family or close friends and remembering images as abstract information.