Some people can't see mental images

It's possible that in some configurations of aphantasia the brain is still doing some sort of processing that is made available via a subconscious process.

So you can't visualize an occluded surface in an active way but your brain still prevents you from running your rear bumper into another car.

Many people with aphantasia still dream at night.

Congenital aphantasia and emergent aphantasia may effect brain structures differently, perhaps some forms just disconnect the pipeline that feeds the brains computed data back into our visual centers for further visual analysis.

It's very interesting, in running down these differences we would probably learn a lot about the brain.

> I understand this will be downvoted by people who have their self-image tied up in this, or synesthesia, or any number of untestable hypothetical mental states that are painted as mysterious superpowers.

FYI, I don't have any part of my self image related to any of this sort of thing (I never think about it except when it comes up in discussions like this, during which I briefly find it a bit interesting and then forget about it again), and I downvoted you because I think you're being confident to the point of cockiness yet talking absolute rubbish.

So please don't assume there's some biased reason behind every downvote you get for that comment, at least some of us just think you're completely wrong.

I might not be the most representative example (I seem to use visual and spatial more than most people for abstract reasoning), but here goes an attempt to convey one data point...

If I imagine a particular model of car, for example, I can instantly visualize much of what the entire car looks like. I can also move my attention around parts of the visualization, to see more detail. It's more than facts, and more than feelings.

This visualization is different than seeing with eyes, and is not confused with that, but seems to be using some of the same machinery.

I could sketch a detailed drawing from what I'm visualizing, a bit like the car was physically there, and I could keep looking back to it for references. But when it's in my head, I don't have to take my eyes off the drawing, and I can kinda merge my drawing and the reference in my head.

In contrast, if I try to imagine the scent of tire rubber, or of cooking, or any other scent, I cannot. Not even the tiniest bit. There's just nothing there.

As a point of reference for comparison, that's pretty dramatic and binary.

Of course, when I smell a familiar scent, I often identify it instantly. And while I am physically perceiving it, I can experience it, and move my attention around it, and introspect on its character, and have other reactions to it (e.g., good, bad, etc.), etc. But immediately after I stop physically perceiving it, I again can't imagine it. I can only recall previously registered facts about it: that vanilla smells good, kinda sweet(?), and maybe creamy(?). I could know more facts if I was a baker or cook, and I guess reason about how to use vanilla, but I still doubt I could imagine perceiving the scent of vanilla in my head.

And some scents will quickly surface related memories of previous times I perceived the scent, even decades ago. And those non-scent memories will remain activated and linger after the physical scent is removed. (Any rare accompanying wow deja vu sense is brief.)

I can picture the visual appearance of various glass and plastic bottles of vanilla flavoring I've seen over the decades, and how some vanilla flavoring looks in a particular stainless steel teaspoon with ambient light reflecting through it, etc. I can also visualize in detail the visual appearance of things that come to mind when I try to think about things I've seen that have vanilla flavoring. I just can't imagine what they smell or taste like.

It might be easier to describe as an eye that is only opened manually, and can only focus on highly specific things. This is my superpower - I can see things vividly in my mind, spin them around, zoom in/out, and more.

When I'm looking at it, the only thing I can see is whatever object is being imagined. However, yes - it's similar to the sensation of seeing with your own actual eyes. The reason it seems so foreign is because our real eyes can see more than one thing at a time. Our mind's eye can only see exactly one subject at a time (though I should mention that when I navigate cities, I do so by imagining a birds-eye view, so there are many objects IN the map, but I cannot see anything other than the map, and it becomes extremely blurry outside of the section I'm focusing on).

After coming down from the shock of learning there are people like you I was even more amazed that one of the founding engineers of Pixar, and a giant in computer graphics, also has this condition. He even did a survey that found his artists where more likely to be on the aphantasia spectrum than managers. Dunno, maybe some people are so driven to create what they cannot think or see.