Some people have no imagination. Literally.
Aphantasia is the emerging term used to describe a rare and mysterious condition in which people literally cannot picture things in their mind. Jules Suzdaltsev has the strange details in today's Seeker Daily dispatch.
It's likely that the condition known as aphantasia has been around forever, but it wasn't identified until the 1880s, and it wasn't technically named until 2015. Dr. Adam Zeman, professor of neurology at the University of Exeter, coined the term. The prefix "a" means "without" and phantasia is the classical Greek term for imagination.
Zeman and his collaborators began studying the phenomenon in 2003, when a 65-year-old man -- after recovering from heart surgery -- complained of an inability to picture things in his mind. The patient, codenamed MX, was given a series of cognitive tests to perform while his brain was monitored with an fMRI machine.
RELATED: The Science Of Hallucinations
The results were compelling: When asked to identify photographs of famous people, MX's brain lit up in all the usual places. But when he was asked to essentially reverse the process, mentally picturing faces from names, the visual processing areas of his brain went dark.
Zeman's research suggests that calling up a picture in your mind requires the participation of regions all across your brain. The frontal and parietal lobes think about what you want to see, while the occipital and temporal lobes provide the actual visuals of the objects. If one of these areas malfunctions or gets damaged, it can result in aphantasia.
When news of the Zeman study was published in Discover magazine, several readers wrote in to say they had never been able to mentally picture things. The stories got more interesting as more people came forward. In a fascinating first-person account over at New Scientist, biologist and aphantasiac Craig Venter suggests the metaphor of a computer without a screen: There's memory, processing, and inputs -- but no way to see what's happening.
Nobody really knows how many people experience aphantasia, but surveys estimate around 2 to 3 percent of the population genuinely don't have an imagination. Perhaps these people represent that inexplicable minority who don't like the Harry Potter books. Science marches on.
-- Glenn McDonald
Watch full episodes of your favorite shows on Discovery GO.
BBC: Aphantasia: A life without mental images
NY Times: Picture This? Some Just Can't.
Vox: Here's what it's like to be unable to visualize anything.