Marco Giancotti’s brain can’t imagine a sunset, the sound of a bell, the smell of bread baking, or little else. In this fascinating piece for Nautilus, Giancotti introduces us to aphantasia, a condition that prevents him from picturing any “kind of sensory stimulation” in his mind.

…as soon as I close my eyes, what I see are not everyday objects, animals, and vehicles, but the dark underside of my eyelids. I can’t willingly form the faintest of images in my mind. And, although it isn’t the subject of the current experiment, I also can’t conjure sounds, smells, or any other kind of sensory stimulation inside my head. I have what is called “aphantasia,” the absence of voluntary imagination of the senses.

My whole life, I’ve been aware—sometimes painfully so—of my own peculiarities, strengths, and weaknesses: A terrible memory, a good sense of direction, and what I felt was a lack of “visual creativity,” among others. I always thought these were just random, disconnected traits, and didn’t think much about them. Who doesn’t have their quirks?