Researchers have found that in certain circumstances the pupils of people with imagination are different from those of people who do have visual imagination.

Think of a pink elephant. Chances are that you now see a huge copy in front of you. While that works for most people, some can’t form images in their head. And these are so-called ‘failures’, people with a rare abnormality that makes them lacking in imagination. Until now it has always been quite difficult to find out whether someone has ‘fantasy’. But a new study reveals a physiological test that can show whether someone has this abnormality.

More about fantasy
As mentioned, fantasy is the inability to visual imagination. It means that one who can perceive senses cannot visualize mental images or, in other words, create images of his own accord. For example, they don’t understand what it means to count sheep before going to bed. Also, they cannot visualize their parents’ living room or imagine certain smells. In fact, fantasy has only recently come to light as a psychological phenomenon. This is partly due to some famous people who came forward with it and wrote about their lack of experience with visual imagery.

In the new study, the researchers studied the pupils of people with and without fantasy. The participants were exposed to high and low light during the experiment. As expected, the pupils of all participants constricted in bright light, while they dilated in the dark.


The researchers then went a step further. To test visual imagery – the mind’s ability to visualize objects – participants were asked to imagine light and dark shapes. Next, eye movements and pupil sizes were studied.

pupil size

The experiment leads to a striking discovery. The pupils of people without imagination were found to constrict and widen even on imagined light and dark shapes. “The pupillary reflex is an adjustment that optimizes the amount of light hitting the retina,” said study researcher Joel Pearson. “It is known that imagined objects can cause changes in pupil size. But we were surprised to see that pupil size changed most in those who could conjure up very vivid images.” What’s also very interesting is that the scanning pupils did not respond when they were asked to imagine light and dark objects.

Physiological test

It means that researchers have found that the pupils of people with imagination are different in certain circumstances than those of people who do have visual imagination. “Our results demonstrate an exciting new and objective method for measuring the ability to evoke visual images,” said study researcher Joel Pearson. “It is the first physiological evidence of fantasy. It means we are now close to an objective, physiological test – similar to a blood test – to see if someone has this abnormality.”

hyper fantasy

The researchers now plan to explore how to scale up this new method. Incidentally, this test is probably not only useful for finding out if someone has fantasy, it may also help people who have hyperfantasy – and can evoke extremely vivid mental images. “This is a really exciting time,” Pearson says. “We are close to a reliable test that could potentially be performed online by millions of people worldwide.”

It is an important step forward. “We know that whether or not we think in images affects the amount of detail in lifelong memories, how emotional we become when reading a book, and how we store events in short-term memory,” Pearson continues. “Our new method will allow us to better understand the brain mechanisms of visual images. And that has big implications for how we think, make decisions and feel.”