I don't see images in my head. Can training give me a mind's eye? Training programmes for people with aphantasia - the inability to create mental images - are challenging neuroscientists' understanding of how we create thoughts What do you see when you try to picture an apple? Last December, I closed my eyes and tried to visualise a potoo. This tropical bird has a "round, kind of pill-shaped head", my mental imagery coach described to me, and is covered with brown feathers. Its cartoonishly large mouth opens like a gaping smile to reveal a pink, fleshy colour, and its large irises can make its eyes seem entirely black.

Ebeyer published posts about famous people who had realized that they were aphantasic: Glen Keane, one of the leading Disney animators on "The Little Mermaid" and "Beauty and the Beast"; John Green, the author of "The Fault in Our Stars," whose books had sold more than fifty million copies; J. Craig Venter, the biologist who led the first team to sequence the human genome; Blake Ross, who co-created the Mozilla-Firefox web browser when he was nineteen. Ebeyer also wanted the Aphantasia Network to be a place where aphantasics could find recent scientific research. For instance, estimating the strength of a person's imagery had been thoroughly subjective until Joel Pearson, a cognitive neuroscientist at the University of New South Wales, in Australia, devised tests to measure it more precisely. In a paper from 2022, Pearson reported that when people with imagery visualized a bright object their pupils contracted, as though they were seeing a bright object in real life, but the pupils of aphantasics imagining a bright object stayed the same. Another study of his had shown that, although aphantasics had the same fear response (sweating) as typical imagers to a frightening image shown on a screen, when exposed to a frightening story they barely responded at all.