I know this will do nothing to dispel your suspicion, but I can see people and places with great clarity, detail, in color and moving, and if I focus on them they are not fleeting (I get involuntary images that are fleeting though).
You'll be right to dismiss my claim -- I'm some random stranger on the internet after all -- but I can only assure you that not only am I not lying, until very recently I thought this was the norm. In fact, I had to be convinced by a friend who suffers from it that aphantasia is not a hoax. I still cannot understand how someone can be unable to see the face of their loved ones unless they are actually in front of them.
As for the red lights in this experiment: they started to change as my eyes became unfocused, and I got some "hypnotic" dizzy feeling after a couple of minutes, but didn't see any shapes and got bored with it so I closed the window.
Imagine you're looking down on a grid of squares. It's a little bit like a chess board, but it's only four squares wide and four squares high. In each square is a single letter, and each horizontal row spells a four-letter word. The top row spells "SEER" , the second row spells "SLAP", the third row spells "HEAL", and the bottom row spells "TRIM". While visualizing this grid of letters in front of you, can you now tell me which words you see running either vertically or diagonally? You should be able to do this by looking at the grid and without having to do any sorting of letters in your mind.
My suspicion is that people who claim they can visualize images perfectly won't be able to do this, despite only having to memorize four words to complete the picture.
I'm on one spectrum (absolutely no imagination), this test might be aimed at the other end.
Note: I do not "claim" to visualize, I can do it, like many others. Remember that aphantasia is the uncommon condition.
I cannot see vertical or diagonal words and in fact have trouble focusing on the words. I can see one at a time clearly, but if I focus on the others the rest become blurry. I can see the checkered board though. I suspect this is because your example is too artificial and analytical.
My visual mind doesn't work analytically like this. I can see the face of my friends and family with lots of details (I can see them with different hair cuts for example), even hear their voices. I can remember scenes from my last vacation clearly, in full color.
But I cannot do a crossword puzzle visually, sorry.
I can see equations floating in my mind, but only if I focus on a narrow section; and I obviously cannot do serious math with them.
I too can recall scenes from my last holiday trip. I can "see" the night time scene at the bar, the placement of me and my friends around the table, the lady in a white shirt delivering our drinks -- but it's not the same as a real photograph. It's a different type of vision altogether. It's possible that there are people who are experiencing the same thing as I am, but are describing what they are seeing as a clear photograph. My argument is that it's not a clear photograph if you can't inspect any details.
In fact, I suspect many of my mental images are inaccurate and my brain is making some stuff up. I'm not claiming to have perfect recall, just that I see visual imagery with my mind :)
I however can hear passages of music I remember well: the opening from Star Wars, parts of Kind of Blue or songs from Pink Floyd, the intro song of many TV shows, etc. I probably cannot pass a test equivalent to the crossword puzzle either, but I definitely can hear the music and it's not just me mumbling in my head.
This is where I think the difference in description is happening between myself and others. I've experienced both visual and auditory hallucinations before. These are indistinguishable from real images and sounds. When I picture things, play music, or talk out-loud in my own head, it's not the same as reality. It's a different type of seeing and hearing. Some people seem to imply that their imagination capabilities are on the same level as hallucinations. They say they can picture things with picture-perfect clarity, right there in the same room with them. I even had one artist say he could overlay an image on a piece of paper with his mind and then trace over it.
I have another test I'd like to ask these people: is it possible to picture a black square that sits in front of your eyes and obscures your whole vision? If not, why not?
It's just a very vivid and detailed experience, but it absolutely cannot be confused with the real thing like an hallucination can.
I can see geometric shapes of all colors but they don't obscure my vision. They "bypass" my vision and go through a different "channel". I cannot confuse myself and suddenly think there's a floating black square in front of me.
FWIW, I don't think the ability to visualize something specifically in your "mind's eye" has a lot to do with creativity.
I interpret this as more about direct recall of memory. The stronger the visuals the more likely you are to be able to recall a specific event/visual in more detail (whether it's accurate is up for debate).
Disclaimer, I have no idea what I'm talking about - I just like this subject.
I've seen absolutely nothing on this flashing screen despite looking at it for around 5 minutes. I don't think everyone else is lying, but i wonder if other people's brains just get "bored" and start imagining things, on a moving visual canvas.
Overall, this was totally disappointing.
I think that's precisely the intended effect of this experiment.
Note that whether people's minds get bored or not, the idea is the same: whether they can visualize things that aren't really in front of them.
I have never been able to do anything close to this, and similarly have self-diagnosed as much weaker in this "power". I mean I can visualize things in my mind but it is fuzzy and fleeting, like focusing on any detail collapses the field of view.
This episode of radiolab about a musician who can maintain a 3d mental image of four orchestras playing at once always stuck with me, and seems relevant to this topic:
https://www.wnycstudios.org/podcasts/radiolab/segments/30142...
FWIW this is sort of a thing that the process of becoming an artist trains you to do. I have been a professional artist for a couple decades and it is much easier for me to do this sort of thing than it was when I was a kid. There's a lot of steps involved in projecting a mental 3d model onto a 2d plane that I can just do in my head now because I've done them so damn many times.
There's definitely an innate level of doing this as well, some people start with a big boost, various psychoactive chemicals can help (I have done so much work while slightly stoned for the performance boost it gives my visual cortex), and then there is that story about one 1940s animator at Warner Bros. who got in a car accident that involved a degree of head injury, and could suddenly just "trace" stuff directly off of his mental images onto paper once he recovered.
But this blinky screen plus white noise gave me nothing after 5 minutes except some slightly brighter and darker areas, and I aborted. <Hercules> Disappointed! </Hercules>
I learned about six months ago that Aphantasia was a thing, and that I seem to have it. For me, this was a cool (if massively annoying) confirmation.
Not sure why they talk about it being "wrong" since obviously you are functioning enough to be commenting on a site on the internet rather coherently....