Scientists can use something called the vividness of visual imagery questioner to measure affantasia. When you look at a bright light, your pupil contracts; when you imagine dark things, it relaxes and opels up again. Scientists can also use brain imaging technology like phmari to see which parts of the brain light up when some one visualizes.
Close your eyes and try to imagine an apple. Can you see anything? Aphantasia is the inability to see with your mind’s eye. Since it was discovered, scientists have been asking the question: What is the mind’s eye even for?
This is the fifth episode of our six-part series, Making Sense.
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