(VR headset required) - VR Aphantasia Tester.
Some people can see images of things that are not there, just by thinking about them. This is not considered a mental illness. For some, this effect only appears when their eyes are closed. For others, they can overlay these images on top of the real world.
Not everyone suffers from this affliction. There are people in the world who can only see what is in front of them.
When you speak to someone who has a different experience of visualization, it can be hard to understand what they mean. One cannot fully grasp what it is like to be inside another person’s mind.
It would be useful to have some sort of empirical test to determine whether someone has this condition. Apparently, there are a couple.
The podcast episode “Aphantasia” by Radiolab describes an experiment where a VR headset is used to show a person two different images for each eye. A green square and a red triangle, for example. Apparently, people who suffer from a lack of aphantasia can force their brain to see ONE image by imagining it strongly enough. E.g. if they think of a green square while using the app, they will only see the green square, and the red triangle will disappear. Aphantasic people will see see both images at the same time, with the red triangle and green square superimposed on each other or flickering between the two.