It’s shocking to realize at 32 that the way you’ve always experienced the world isn’t quite “normal.” That there’s something you’ve been missing out on without knowing it. All these years the concept of mental imagery never made sense to me. When people said things like, “I can still see everything vividly,” I thought they were being dramatic. I didn’t think people could imagine images floating around in their heads. I was confident that “counting sheep” was just a metaphor. And when my soccer coach told me to imagine scoring a goal, I just thought of concept to score a goal. I only had words, descriptions and details echoing inside my skull.

But then my therapist recently asked me to close my eyes, imagine myself in a safe place, and wait for parts of me to come out. As usual, I didn’t “see” anything. I just answered with something I believed he called right: I saw myself perched on a boulder, in my favorite spot along the Eno River, as my childhood me walked up to me today, in a pair of overalls and a green neck, and a “dark” version of me, representing my depression, lurked. on the other side of the river. When I forwarded these images to him, I felt like I was faking them. As our sessions continued, I tried so hard to get into an altered state where I could “see” these figures; sometimes, after intense concentration, I experienced something like blurry dream images, but that’s about it. After I got out of it, I wanted to evoke these versions of me, to process what they meant, to return to them. But most of the time I saw nothing.

As I now found out, there is a name for the mind blindness I was experiencing: aphantasia. People with aphantasia cannot form mental images, or what little they see is vague and vague. An estimated 1 to 4 in 100 people have aphanthasia, and those who do sometimes refer to themselves as aphanthazis, aphantasias, or aphantasiacs. We generally self-identify, because there is no way to confirm whether someone has it or not. Even for people participating in studies, the way to “diagnose” aphantasia is with a visual imagery intensity questionnaire.

Aphantasia was described first in 1880 by British psychologist Sir Francis Galton. After asking participants to recall the lighting, definition and colors of their breakfast table as they sat down to eat that morning, he found that for some, “the power of visualization was zero.” More than a century later, in 2010, Adam Zeman, MDa neuroscientist at the University of Exeter who studies visual imagery, published case study of a 65-year-old man who suddenly developed aphthasia after a cardiac procedure. In other cases, he noted, people have lost their mental images after head injuries. As a result of the news of their work, Dr. Zeman and his team received many stories from other people who had similar experiences.