You've heard of aphantasia (no mental imagery) and hyperphantasia (extremely vivid internal imagery). But there's a third dimension researchers have only just begun to formally study: prophantasia - the ability to project mental images not into your mind, but into the world in front of you.
For decades, researchers measured one thing: how vivid is your mental imagery? But vividness only describes the intensity of an image. There's a second, entirely separate question science is now asking - where does the image appear?
How vivid, clear, and detailed is your mental imagery? This is what the VVIQ measures - from aphantasia (none) to hyperphantasia (photorealistic). This is the dimension most people know about.
Where does your imagery appear? Internal (associator) - experienced in a separate mental space, eyes closed, behind the eyes. Or External (projector) - overlaid onto the actual visual world in front of you. This is what prophantasia measures.
Critically: vividness and location are not the same thing. You can have hyperphantasia (extremely vivid) imagery that is entirely internal. Or you can project imagery externally at moderate vividness. They're separate dimensions of the same system.
Many people who take imagery tests like the VVIQ score lower than their actual imagery ability - because they're looking for the image in front of them. If you're a projector (prophant), you naturally expect to see the apple in your visual field. When it doesn't appear there clearly, you assume your imagery is poor. The VVIQ wasn't designed with external imagers in mind. This distinction may be responsible for a significant proportion of "borderline" test results - and understanding it is one of the most useful things this site can offer you.
This distinction was first identified in synesthesia research - some people experience their synesthetic colours in external space (projectors), others experience them in mental space (associators). Researchers have now extended this framework to general mental imagery.
This is genuinely new science. The formal term "prophantasia" - and its systematic study as a distinct dimension of mental imagery - was introduced in research from the University of Liverpool and University of Oxford.
Researchers Azañon, Pounder, Figueroa and Reeder set out to replicate a highly-cited 2007 study that claimed more vivid imagers show stronger interference between imagined and perceived visual information. Recruiting 241 participants including people across the full spectrum from aphantasia to hyperphantasia, they found they couldn't replicate the original vividness–interference link.
What they found instead was more interesting: a new measure of imagery "externalism" - whether people experience their imagery in the external visual field - did predict perceptual interference effects. People who reported projecting their imagery outward showed stronger congruency effects between imagined and perceived colour, suggesting their projected images were genuinely interacting with real visual processing.
This study reports a new measure of imagery externalism - the ability to embed mental images into the external environment, similar to how virtual images are embedded into the external environment in augmented reality. We call this ability prophantasia. - Azañon, Pounder, Figueroa & Reeder
The results challenge the assumption that vividness is the primary dimension of imagery that matters for perception. They suggest that where imagery appears may be as important as how vivid it is.
When a projector overlays a vivid mental image onto the real world, the brain appears to partially treat it as real visual input. In experiments, this creates measurable interference - projectors take longer to process actual visual information if it conflicts with what they're projecting.
Think of it as a transparency layer in Photoshop applied to reality. The layers interact. If you project a red shape over a blue surface, your brain's visual system has to reconcile two conflicting signals in the same space - unlike an associator, whose imagery and perception don't share the same "channel."
This is the question prophants most need answered, and the distinction is important and clear. Voluntary control. A prophant chooses what to project, when to project it, and can dismiss it at will. The image appears because they intend it to.
Hallucinations, by contrast, are involuntary, uncontrollable, and often indistinguishable from reality to the person experiencing them. Prophantasia is a high-functioning imagery ability - the brain's visual system is simply more integrated with the imagination system. It is a feature of perception, not a symptom.
A simple self-report screening to help you identify whether you might be a projector or an associator. Not a clinical test - but a useful first step.
Look at the grid below. Stare at the centre region (the dashed box). Now try to imagine a bright green triangle and "place" it in the centre of the grid. Take 20–30 seconds. Then answer the question below.
When you imagined the triangle, where did it appear?
This is a simplified self-report screening, not a validated clinical test. Research on prophantasia measurement is ongoing.