‪Sebastiaan Mathôt‬, an experimental psychologist at the University of Groningen in the Netherlands who studies pupillometry, said it’s widely accepted now that our pupils change sizes in response to many things, not just light. For instance, if two people are asked to imagine an apple, and rate how intensely they’re visualizing it, they could be imagining the same thing but give different ratings depending on how they interpret their visualization. The VVIQ can assess for the intensity of a mental image, but could also inadvertently measure metacognition, or how aware a person is of their own thoughts. In 2015, Zeman and his colleagues published another paper on 21 people who had never had mental imagery, which they dubbed congenital “aphantasia.” The Greek word phantasia means 'imagination.' Now, thousands of people have answered the Vividness of Visual Imagery Questionnaire (VVIQ), and it’s estimated that around 2% of the population might have aphantasia.īut as aphantasia research has continued, those who study it have tried to find new ways of measuring it. Zeman published a case study on the man, known as MX, which the science journalist Carl Zimmer wrote about in Discover in 2010. In 2003, a neurologist from the University of Exeter, Adam Zeman, met a 65-year-old man who lost the ability to mentally visualize people and places that were familiar to him after a surgery, though he still performed normally on other tests of perception, visual imagery and visual memory. “To my astonishment, I found that the great majority of the men of science to whom I first applied protested that mental imagery was unknown to them, and they, looked on me as fanciful and fantastic in supposing that the words ‘mental imagery’ really expressed what I believed everybody supposed them to mean,” Galton wrote. This was noted at least as far back as 1880, when Francis Galton, the polymath, eugenicist, and cousin of Charles Darwin, asked 100 men to describe the table where they ate breakfast every morning, and found that some couldn’t do so very well. On the far end of the spectrum are people who can’t imagine visuals in their minds at all. There is a wide range in how vividly people experience imagery in their mind. It’s part of your brain that is exposed to the world.” “But the retina is literally part of your brain, like a little bit of your brain is pulled out.

“It is called the window to the soul,” said Joel Pearson, senior author on the new paper, and a psychologist and neuroscientist at the University of New South Wales. Further probing the connection between pupil size and mental imagery could also provide a tool to better understand how we all visualize in our minds.

Constricted pupils psychology