Hacker News Reader

Comment by mk12 | Hacker News Reader

I've never understood how people talk so objectively and confidently about this. There are subjective things we'll never able to compare, like whether your experience of red and green is the same as mine or swapped. Then there are other things like face blindness that have testable effects in the real world. When one person says they see 80% clear mental pictures and another person says 10%, how can we be so sure they aren't just describing the same experience differently? I have no idea how I could accurately report my experience of the apple test. I could say I see it clearly or not at all depending on what you mean by seeing.

EDIT: It also reminds me of the "inner monologue". I'm skeptical when people confidently claim they have no inner monologue, as if it's as easy to verify as being right-handed or left-handed. In the context of meditation, it's common for people to confuse "having no thoughts" with "thinking nonstop" -- it's not an easy thing to understand about yourself, let alone claim how it relates to other people's subjective experience.

View on HN

The thing that finally made me very confident that I had aphantasia (back in 1998, before it was A Thing) is that I realized that my ability to "hallucinate" sounds is excellent. I can re-hear songs in my head, I can compose music and hear it as I think about it, I can hear my friends and family talking with their particular cadences and accents. I can't do anything remotely like that with visual images. Before I had that realization, I thought it was pretty possible that I was "just describing the same experience differently".

Conversely, I discovered I had anauralia (finally got a name for my inability to "hallucinate" sounds). I found it when I was hosting a weekly event and meeting lots of people. And we talked about senses and memory, etc. And one day I realized I have no sounds in my memory, nor do I get songs stuck in my head. I asked others and it was instantly clear they had a different experience than mine.

We have algorithms that can hallucinate now.

LLMs basically are examples of how humans visualize things. With a few differences. Humans have more fine grained control over the result and understanding of a query. LLMs have greater detail in the sense that the LLMs knows the location of every wrinkle on a face while our imagination delivers an approximation with detail only being rendered if we decide to focus on the details.

This is interesting - if you think of a popular tune, say, the opening chords to Hells Bells, (or whatever is popular for you) doesn't it make an impression in your head from chord to chord? I'm not saying it's identical to hearing a sound, but loud enough to kind of crowd out everything else in your head (to the point of actually being annoying?)

The thing I never got with the "Close your eyes, can you visualize a Red Star" - is that I can "conceive" what a red-star is like but I can't even imagine what "visualizing" a red star would be - do people actually see the red star in their head in the same way that I'm hearing Hell's Bells in my head? Or are there people who can actually pick up the actual image in exactly the same way they hear a sound? (I'm presuming not)

There is zero difficulty in my mind distinguishing between the sound I hear and the sound in my "head" - but at least I have an ability to hear sounds.

On the flip side while I have absolutely no ability to view images in my head 99.9% of the time, about 0.1% of the time, usually just in the 5 or so minutes before I fall asleep - I do see thinks in my head - to the point of being fascinated by them - but in this case - I'm actually seeing things, even though I have no control over it. It's different from when I'm hearing things - because that is mentally hearing things, whereas when I'm seeing things as I fall asleep - it's not mental at all - I actually see them (albeit with my eyes closed). It's a real image - not a mental one.

You are the first person to have given me a sense of what it means to "visualize" if it means something similar to "hearing" a song in your head.

It's also different from the inner monologue, btw. That's identical to my ability to hear sounds. Clearly there. Clearly mental. Sometimes chatty to the point of being distracting - but there is no doubt whatsoever that it's a mental dialogue - nothing whatsoever like actual sounds.

I see a 5 point star with a red glow and sharp edges, with two points in the middle of each side of the centre of star illustrating depth. I can "twist" it in my mental space and see the gradients shift.

The imagination spectrum applies to all senses, so we all have varying degrees of it. Some can visualize every sense very well, others only vague faint unclear versions, some a mix!

What other senses can one imagine or not? Never considered it.

I can recall/imagine taste, smell, vision, hearing, touch (texture and temperature), body movement, spacial awareness, and maybe more.

I can vividly imagine doing a physical feat, all the imaginary senses and sensations. Same as hearing a song in my head or imagining a red star.

It follows that there are others who can't imagine the other senses. What super imaginary powers might someone else have that is equally beyond my own? I heard of a guy with synesthesia who imagined numbers as complex 3d shapes and he could multiply large numbers in his head by, lego style, combining the shapes. The mind is wild.

obviously not at all an expert or even qualified in the fields of neuroscience or psychology, so speaking as a layman, but I think it's all a continuum, from your external sense organs like ears and eyes via the connecting nerves to the inner reaches of the brain.

I think the initial stimulus can originate at any part of this circuit.

So I do not think there is much difference between external so-called real stimuli and internal ones.

it's all just vibrations, processing, and reverberations :)

> I'm not saying it's identical to hearing a sound, but loud enough to kind of crowd out everything else in your head (to the point of actually being annoying?)

I'm the same way and my impression is that, no, most people don't have an auditory imagination anywhere near that strong. I actually work hard to avoid songs that are notoriously catchy and annoying because I know I won't get the earworm out of my head if it gets in.

I basically always have a loop of music playing in my head. Which piece of song is stuck playing in a loop varies over time, but it's very rarely silence. Often, it will be a sort of jumble of a couple of different things. (Right now it's a line from some annoying meme song my daughter just sang and a bit of the bassline from Basement Jaxx's "Red Alert".)

I'll often wake up with a different song stuck in my head because there's music in my dreams too.

> about 0.1% of the time, usually just in the 5 or so minutes before I fall asleep - I do see thinks in my head - to the point of being fascinated by them - but in this case - I'm actually seeing things, even though I have no control over it.

This is called a "hypnagogic hallucination" and is pretty common for all people to experience.

Hypnagogic hallucinations for me aren't in my head -- the objects (always lots of spiders) are as real as reality, but instantly disappear when I put the light on, leaving my brain trying to figure out where they went (it takes time to realise it has been tricked).

I can't really see objects in my head, but music I can play perfectly like it's an iPod. Usually just gets stuck on one track all day, though.

I know I've heard Hells Bells before because the name is recognizable, but I have literally nothing coming up when trying to imagine what it sounds like.

Another fun story. I did improv comedy for a few years. One of the warm up games we played was someone would start singing a song, then another person would tag you out and sing a different song. I was bad at this game. But I have a few simple things in my back pocket to "play". Somewhere over the rainbow is one of them. The last person was doing some sort of rap, and what came out from me was a rap version, until the crowd helped correct it. I just have no idea what it sounds like other than trying to memorize if it's a high pitch or a low pitch, etc.

Regarding the inner monologue, I do have one. And it feels similar to my ability to visualize. I can control it, give it emotion per say, (not sound for me), but it isn't as strong as a memory of a dream.

Are you saying you can't remember any songs?

I can hum Jingle Bells (or 1000+ other songs, the Star Spangled Banner, Rudolf the Red Nosed Reindeer, any pop song from the last few decades, etc...). The experience of imagining the song is the same as humming it except I don't actually hum it.

It sounds like you're saying you can't hum a song or even remember one? Can't remember anyone's voice? Can't rememeber the sound of fireworks? Of cars going by?

Not the guy you’re replying to, but his description matches my experience.

I can’t hum songs anymore complicated than the “Happy Birthday” song (but if it plays, I’ll recognize it).

I can’t remember people’s voices in my head (but if I hear them speaking, I’ll recognize it is them).

The bang of a fireworks or a car going by is simple enough to recall. It is also generic. I might not remember the hum of the engine of a specific car, or be able to play back a specific fireworks display.

Same here. Plus aphantasia.

Explains why I had such difficulty singing my whole life. It must be way easier if you can just recall a song in your head and match its pitch!

I cannot sing but I can create songs in my head including multiple instruments and vocalists. Admittedly, I have given singing very little effort past age 8.

Yes, this is essentially my experience. I can't recall sound, but if I may "tag" features to a sound so that I can somewhat imagine it.

Like the idea of a firework bang, being low intense vibrations, or a car horn being a high pitched short startling sound. Still can't really imagine it like I can picture things in my head, but I have an idea of the what the experience would be like.

> do people actually see the red star in their head in the same way that I'm hearing Hell's Bells in my head?

Yes, that's a very good description of what the experience is like.

When you're auralizing(?) a song, you can choose which memory of the song you're listening to, and you can tap along with the beat, whistle along with the melody, sing along with the words, while being absolutely conscious of the fact that you're not actually hearing the song, right?

Visualizing something is the same, you can manipulate the image in your mind, rotate, choose different memories of the thing - or imagine new ways the thing could look, while being absolutely conscious of the fact that you're not actually seeing the thing in front of you.

When you said "red star", I imagined a red giant star, protuberances and sunspots and all, floating in space. Then someone else commented about a "five-pointed star", so I shifted my imaginary image to a stylized five-pointed red star icon instead. Same as you would imagine listening to one song, and then swapping to a completely different one with the same title.

With visual memories - so it’s something like that interface from Minority Report?

Can be. It's easier to project it on inner "canvas" than as overlay on top of ambient, but that's still possible.

Hell's Bells start with a loud pulsating synth percussion and fanfare playing the theme, not chords. Great choice though, as it's extremely memorable, but, unfortunately, hardly popular.

To the rest of your comment, it's fascinating how it's all a spectrum. I can't visualize a star, can hear sounds but have no inner monologue.

I'm not sure what "Hell's Bells" you're thinking of, but the GP is plainly describing the song by AC/DC from 1980. It most definitely does not contain pulsating synth percussion, but is extremely popular.

Right, blanked on that one. I immediately thought of Bruford's one, a real earworm.

Trying to imagine that it does is quite fun, though.

To communicate to others my experience with imagination versus hallucination in discussions like this, I've used the device of seeing differently from either eye at the same time.

If I put my hand a couple inches away from my face, in front of one eye only, I can still 'see' aspects of that hand with the uncovered eye.

Analogously, when I imagine a 'red star', it is visible in a different medium / realm (like my covered eye) than the rest of the things I see around me (with my uncovered eye). I can 'insist on' or 'overlay' the imagined image, like the red star situated in a particular spot on my desk, but I do not feel that they 'become the same visual stream', ever, such that I would think that the star could be physically present in the room.

I'm also a more auditory person in that I can imagine a whole orchestra playing in my 'minds ear', among other things.

I've recently been wondering about the fact that I am pretty sensitive to sounds and may have trouble concentrating in a very noisy environment (especially if the sounds are not constant/predictable.)

My hypothesis is that this inability to concentrate well in a noisy environment is a trait that mostly affects people who are more 'auditory'. Thoughts/experiences?

I get songs stuck in my head but only as if I am humming them to myself, never sounding like instruments or the voices of other people. And I'm not a good singer, so it's infuriating.

I'm so glad there are conversations about this. I'm the same way here - in fact, part of the way I keep track of time passing is to listen to a song in my head. I've had really strong aural hallucinations here and there in my life. A doorbell, clear as clear gets, except I know it didn't happen.

And so many things I read about aphantasia are spot-on aligned with my own experience, but put into a comparative context I hadn't really thought about until the word was more or less invented a decade ago, and the idea leaked out into the internet. The line about "weaker autobiographical memories" in this article really hit home for me. I take so many photos now - thank goodness for digital photography - and in the context of this topic, it's no wonder.

I've also struggled to remember dreams, all my life - and also thought the 'counting sheep' thing never made sense, at all.

Do people with aphantasia do badly at Pictionary?

I often get really detailed mental imagery. Often unbidden, when daydreaming. My drawing skills are ok too.

When I partner with my brother it's almost telepathy. I can draw a single curved line and he'll correctly guess 'elephant' before any players have even put pencil to paper.

From the two studies I saw, the difference would be in drawing details and colors, but not in spatial or high-level features. So, I'd guess it could be a small difference in Pictionary.

I can visualize zero but I dominate at pictionary. Different part of brain

I’ve always wondered about this too.

I can’t imagine/see mental images the same as having a real screen in front of me.

I can imagine a triangle. I can’t “see” it, it has no color and no brightness/darkness. Can’t really even describe the size. More like feeling around in a dark room. But the triangle is gone the instant I stop thinking about it. I wouldn’t be able to imagine a game of Tic Tac Toe.

Some people call this normal, some don’t. I have no idea.

I can imagine music too — and find it takes far less effort. (But can’t remember exactly what I imagined — more like just enjoying as it happens)

I have higher than average ability to visualize mental images. It's not like a screen but more like wearing augmented reality glasses with very low brightness/opacity to the point where the images have only 1% solidity. Also, the detail level of the images is low, similar to an impressionist painting. However, properties of color, size, and 3D spatial location and orientation are all well-defined, so for example I can imagine a (very low opacity, very rough, impressionist style) picture of Mario or Luigi standing upon this line of text on my screen and being 1 inch tall. It's my understanding that this level of capability is higher than average, but less than talented artists like painters or sculptors. Despite not being good enough for a career in art, this mildly better than average ability level, combined with being able to code, allowed me to be quite successful as an augmented reality prototyper in the first half of my career.

It looks roughly like the detail level of picture "C" in this picture: https://history.siggraph.org/wp-content/uploads/2023/02/2014... But with much less brightness/opacity/solidity than that, maybe 20x less (i.e., only 5% of the brightness/opacity/solidity of the tie fighter image - but same level of lack of detail)

You can improve this ability through practice. If you spend 10 minutes every day concentrating on visualizing that triangle with more detail & specificity, like an art student would, you'll gradually improve.

There's little to indicate ability to visualize correlates all that strongly to art skills. E.g. Ed Catmull of Pixar fame has aphantasia, and on learning about it surveyed Pixar's artists and whole I think he found some correlation, some of their most talented artists also had aphantasia.

I have it, but could draw pretty well when younger (not practiced in decades). What I found, though, was that my style was very different depending on if I drew from a model or from memory.

There was research into this and you’re right that it doesn’t correlate necessarily.

People with aphantasia are absolutely crap though with drawing anything from memory, but they can draw if something is in front of them.

As I pointed out, I could draw just fine from memory, despite aphantasia. So could many of Pixars animators.

How clear are images in your dreams? Clearer than picture "C"?

Mine are clearer than picture "C" though when I try to focus on something they tend to fade to black. Sometimes though I have dreams in HD where when I focus on something the details reveal themselves and everything is clear and sharp.

I don't think internal audio and visual imagery are comparable. Things you see have no time dimension (like a photo is just one instant). A song, on the other hand, is a "stream" of audio, a sequence of sounds, and therefore has a time dimension - but no height or width or shape whether you are hearing it live, listening to a recording, or playing it back in your head. It's not tangible, there is less to remember (like an audio file is just a tiny percentage of a video file).

All I'm saying is plenty of people can play back songs in their head, or replay a conversation (or practice a future one) - it's why having a song stuck in your head is a universal experience - but not be able to internally "view" or "picture" objects with anywhere near similar fidelity, and therfore being good with sounds but bad with imagery is quite common, and not indicative of a condition (which is being called "aphantasia" here.)

When another poster described a red star with sun spots I started forming a moving image in my mind of a sun with swirling in motion sun spots

It sounds like you're talking more about memory than ability to imagine? As a child I used to watch cartoons in my head when lying in bed at night waiting to go to sleep - they weren't remembered though; excepting they were abstracted from actual cartoons.

I have very poor ability to imagine/remember music. Though curiously I'm good at "intros" (guessing songs from the first few notes); I couldn't hum you the first few notes of anything.

Or maybe you just have some aphantasia?

My visual imagination absolutely can have a time dimension just like my audio imagination. I can remember sequences of film from movies I have seen many times with high level of detail, and then if I so choose change what happens in that sequence to whatever I want.

I think it's more that as humans our audio fidelity in general is less detailed than our visual fidelity so it is easier for us to notice limitations in our ability to imagine visuals than in our ability to imagine audio.

Hmm. Me too; you're describing me. But I'm a skeptic on this subject. I can't help but think this is just too prone to fantastical and placebo-like thinking. I can't help but suspect that the vast majority of people experience the same thing---they just describe it differently. It's also unscientific, and that has to mean something.

(I don't mean to be dismissive; I do think this is an awesome topic to debate and talk about though, it's a great path for us to maybe understand qualia a bit deeper, if that's possible at all.)

The difference is dreams and imagination for me. Ask me about an apple while awake and I’ll close my eyes and it’s dark blackness of a void.Extreme aphantasia (I also am face blind)

Ask me about it while dreaming and it’s a full on 3D movie/VR experience.

Music too I can play that in my head no problem like my own radio (unless it has words then I can’t imagine it at all) - so I suck at karaoke. Even trying to sing with songs I can’t process it correctly unless it’s tonal sounds from the words.

For a neuroscience background we are certainly not all wired the same. You are correct though that aligning those descriptions and untangling social meanings and words from experience is tricky.

> Ask me about an apple while awake and I’ll close my eyes and it’s dark blackness of a void.Extreme aphantasia

Uhhhhhhhh.......I don't think that's extreme at all. Isn't that normal?? I just asked several people today to close their eyes and imagine an apple (or anything else) and everyone just sees black.

If you could see objects with your eyes closed, I think that's called having a photographic memory? (Which is...rare?)

This is where the confusion stems from.

I can have very vivid mental imagery, I can imagine all sorts of fantastical things in detail in my mind on command. But that doesn't mean I don't see black when I close my eyes. It doesn't mean the mental imagery blocks what I can see normally with my eyes open. It is in your "mind's eye", so it is still triggering the vision parts of the brain, but almost like its on a different screen.

Similarly with imagining sound or music. I can almost perfectly recall some of my favorite music, I can compose a new piece (poorly) in my head based on music and sounds I have heard, but none of it will drown out an actual sound I hear around me.

That being said, if I am very mentally focused on some mental imagery it can still distract me from my real vision and or even sort of "replace it" without my closing my eyes. Sort of like the feeling you get when driving and zoning out thinking about something (but you are still safely driving).

Do you have dreams?

If so do you see things in these dreams?

I have aphantasia, and what makes me very certain is 1) that I have dreams and see things in them, and I experience nothing like that in a waking state, 2) except one time when I experienced something far clearer while meditating. It felt like walking around a movie-set in that I was 100% aware it was not real, but it looked entirely real; at the same time I knew that I was sitting and meditating and was still aware of my breath and the sensations of my body. It's possible it was a lucid dream, but I've also never had a dream that clear before or after.

Either way, I've experienced a range, where my normal day to day experience is no sign whatsoever of seeing anything except maybe occasionally sub-second vague flashes, and the best I've experienced was as if I was looking straight at a real scene. So my day to day experience stands out very, very starkly against both my regular dreams and that one experience.

The frustrating part about that experience is that it suggests I can see things in the right frame of mind, but I don't know how to bring it out.

Thanks for your insights.

I suspect the mind is just like a body in the sense that the more you engage a particular muscle the easier it gets.

When I’m struggling with something I find it helpful to reframe statements into questions to activate creativity and clear any unconscious barriers that the mind is enforcing.

I'd put myself into a similar category. Songs I can hear instruments in my head, my "inner voice" is very clear and I'm able to have conversations with myself (for example when coding).

But when I close my eyes I describe it best as a black-and-orange static. I'll occasionally get residual images. Ask me to describe something in detail I struggle - but I can conceptually describe a space for example.

These are very different to what I "see" when I meditate for example, which is more dream-like (and I assume similar processes kicking in)

Same. My mental image is like an after image from staring too long into the sun. I think it‘s best described like being similar to how echolocation in a sense. Just traces of objects and their positions.

I've gone back and forth trying to decide whether or not I have aphantasia, mainly because like you internal sounds are so vivid for me and it's not at all the same for my visual phenomena. But after doing visualization practices as part of my meditation practice I think it's something I've gotten a lot better at. Often in vajrayana buddhism you'll be given some visual object to meditate on (a buddha, mandala, a river flowing, fire, etc) and at first there is a lot of discursiveness to it while you're meditating: the trees look like this, the river is flowing this way, the shadows are here, etc. Then that sort of dies down until (for me) a very vague image starts to appear. It's in a different space than where my eyes would produce an image, it's more dream like, and you sort of just let go of paying attention of visual phenomena that arise at your closed eye space and go to a more immersive dream space where you're sort of in the scene itself.

But maybe I have aphantasia and am totally wrong!

I think there's a profound difference in the aural vs. visual experience. For me, imaginging songs, "hearing" an earworm, even for songs in other languages, I think I'm using my inner monolouge system. Instead of thinking, I'm "inner humming". The profound difference being, we can produce sounds, we can sing, hum, go "ba-doom-tish!" in our heads. But we can't (at least I can't) produce visions at will. I must be able to in some sense because I remember things I "saw" in dreams. And I can get a sense of places I know - usually the best remembered are from my childhood. Things that I've remembered a hundred times. But if you ask me to imagine an apple, there's nothing to be seen even though I can think of its shape, and details and draw what I'm thinking of, which is basically a memory of an apple. However, at night, with eyes closed when drifting off to sleep, if I think about what my closed eyes are "seeing" I can get very vague impressions of random things. On occasion I've been able to influence what pops in there to an extent but I can't do it on command. What I think is happening here is there's enough noise in my visual processing that lines up to remind me of something - a house, a tree and my brain fillsin the rest. But even this is like a looking at a photographic negative with candlelight that goes out after 250 ms.

Some people can play chess blindfolded. There is a popular method of memorizing which has one visualize the placement of objects in a familiar space. Both of these seem absurd to me, as I can at best conjure a fleeting glimpse of an object in greyscale. When I calculate chess tactics I do so in a manner which seems almost kinesthetic, as if I’m feeling the movements of the pieces, and I have to look at the board while I do it. When I memorize things, like poems or the digits of pi, I just repeat them until each element of the sequence magically evokes the next. There is no visualization.

Some can play the piano blindfolded. Is it also connected?

No, that is muscle memory. If I play the piano with my eyes closed, I'm not visualising the piano, I'm focusing on the feel and positions of my fingers

This is my experience as well. I would also say that when improvising I’m not really thinking consciously about the movements, but rather the notes I want to hear.

Those two example skills are probably unrelated, like two aspects of the same what-are-your-brain-interconnects problem.

I can place symbols and move them, but I can't imagine a realistic flower; if I tried hard enough I could memorize a chess boards, but the pieces wouldn't have exact shapes as such, everything would be just a representation of a thing, not comparable to a visual memory of seeing the layout. In programmer speak, I think in nodes, graphs, connections. I can imagine people moving in a room to great detail, but not at all their faces or clothing.

I'm strongly spatial but not photographic at all. You're probably strongly tactile, and you learn a poem as if it was muscle memory of a movement.

> I have no idea how I could accurately report my experience of the apple test. I could say I see it clearly or not at all depending on what you mean by seeing.

Same on my end. As far as I'm concerned, I don't see an apple, but basically just in the sense that I'm not hallucinating—with my eyes open, there is no apple before me, and with my eyes closed, there is no apple on the insides of my eyelids, and I don't think that there is. I feel like I could answer questions about the appearance of my imagined apple, but I don't literally see it. But does that mean that I have aphantasia? Since this seems to be the main diagnostic instrument for a casual Googler, and since, as you say, there's no way for me to understand whether or not other people "really" see an apple, I have no idea.

(If people think that your point about never really knowing what other people are seeing is merely academic or philosophical, I'll mention that my mother went a long time before getting her amblyopia treated because she assumed that's what things looked like for everybody. Nothing in ordinary conversation told her, or anyone else, that her vision was different, and so no-one ever thought to test her for it.)

Similar to colour blindness, someone with amblyopia cannot fake not having it, and it’s actually difficult for someone without it to fake having it.

The same cannot be said of aphantasia, which is trivial to fake and almost as trivial to mask. Combine this with some social desirability bias, and you have a perfect recipe for a complete non-condition.

Every once in a while, before falling asleep I enter a "mellow" state in which I can conjure mental images dramatically more vividly than normally. I would say that normally it varies between 10-50% of vividness (also depends on the state of mind, the day, whether I'm under the influence of different chemicals), and in this state of mind it's 90%+ vivid.

And I don't confuse this state of mind with lucid dreaming: I had spontaneous lucid dreams a few times. They were not very vivid, just as my normal dreams (I dream in images, and they are maybe around 50% vivid).

So, there is definitely a way to experience variation of vividness of mental imagery, by a single observer.

I have this too, especially when I’m really tired. It’s such a surreal yet refreshing experience. I can hear the most beautiful melodies my ears have ever heard, even though I don’t have a musical bone in my body. And I jump in and out of various vague visual scenes (like staring into deep space) during this.

It always makes me question if I’m dreaming or not - and often, it’s the last thought I remember before I actually drift off to sleep. All of this seems to happen during the span of 60 seconds max (judging from my heartbeats), but this has categorically been debunked when my wife once told me I was actually snoring for a couple of minutes.

The melody thing I assume I have not suddenly become a master composer, rather the part of my mind capable of judging whether the music is any good has become impaired.

I don't consume chemicals but do meditate.

As I drift off to sleep sometimes it's fun to shift the inner eye to observe the mind and watch images float across my "viewport".

> They reported actually seeing an apple, some vividly and some faintly, floating like a hologram in front of them.

This is the line in the article that gets confusing for me. Like, are some people actually seeing an actual image of an apple, as if they were wearing VR goggles or something?

Where you fall on the imagination spectrum depends on how clear the object you are asked to visualize is in your mind.

For example if asked to visualize a green banana, and you can only see vague, unclear, faint outlines of a banana, that's hypophantasia. If you cannot see an image at all, it's aphantasia. Some might see vivid details of the banana, like the matte skin and subtle green gradient, they fall under hyperphantasia. Others who lack the details but are still clear considered phantasia.

This also applies to all other senses, like being able to imagine a sound or smell.

But surely nobody sees the fruit rendered into their actual vision as if all mental imagery appears as a literal hallucination in their vision.

Visual hallucinations due to mental illness are uncommon but not unknown. I'd be reluctant to dismiss the idea that someone on earth can and does do that. I'm pretty far down the visualization direction myself.

I've done a meditation where you sit open eyed and visualize something within the space.

It was cool. Sort of like a hazy projection over the visual field. Normally when I visualize something with my minds eye it is on a black background. When the visualization ends my visual field snaps back to reality.

Yes.

The imaginary apple doesn't seem fully comparable to a real apple unless I'm in a very focused and compelling daydream, and even then real but not real at the same time, if that makes sense. But even now if I was to conjure an image of a faint, ethereal apple in front of this computer screen, I can do it easily.

The major difference is VR goggles are fully vivid, and remain so when I'm not willing them to be, and tangible in some sense I'm sure is indefinable with people to aphantasia. The VR goggles are real in the same way things that aren't dreams are real.

Does the imaginary apple block you from seeing the comouter screen behind it? If you can honestly say it blocks your vision, like a real tangible apple, I'd give some credence to the idea (and also suggest that you not be permitted to drive, as it would be incredibly dangerous if simple thoughts could block you from seeing an actual car or stoplight in front of you).

It's perhaps a little like holding your hand up in front of one of your eyes but not the other. It "blocks" your vision, but you can still see behind it.

I don't personally have such a vivid visual imagination, but there are moments when it can feel like that — I won't know what I was physically looking at because I was so concentrated on a visual(-ish) mental image that obscured my awareness of the real world, to a degree.

> I won't know what I was physically looking at because I was so concentrated on a visual(-ish) mental image

Like the guy above, you should not be allowed to drive a vehicle.

Alternatively, if I am physically able to close my eyes during driving then I should not be allowed to drive?

If you are unable to prevent your eyes from closing, yes, absolutely

No blinking allowed while driving?

You seem really angry that people are able to do this.

> I won't know what I was physically looking at

> obscured my awareness of the real world

Yes - because these are the same symptoms as someone who drives drunk and kills someone - "didn't see anybody walking there" (= unable to tell what you're looking at) "just a little buzzed" (= obscured awareness of reality) "I don't know what happened" (same)

You seem to have left out "because I was so concentrated on a visual(-ish) mental image" which is very convenient for your strawman argument. As noted, it takes a lot of concentration to maintain these visuals and it's not something you can do while multitasking. Imagine you are day dreaming and a friend waves at you but you didn't notice because you were lost in the dream. Maybe you don't get it because you are incapable of visualization but saying it's like being drunk is incredibly stupid and ignorant.

He doesn't say anything about it being voluntary or not. Day-dreaming isn't voluntary, that's why your friend can awkwardly interrupt you with a wave (as opposed to turning out the lights and closing the door which would be indicative of purposely napping/sleeping). In any case, people often get into heavy conversations while driving, especially on cell phones. Work-related, family-related (also, audiobooks), whether or not you choose to acknowledge it, people do get into "deep concentration" mode while driving, the difference is that most of us don't claim to actually see images in front of us while thinking of them.

Bit of a thread since my initial comment (:

Just to clear some things up, in case anyone cares:

(1) It is largely voluntary, what I tried to describe. Just like choosing to focus on your phone or the kids in the back seat while driving is voluntary. All of those are, of course, bad things to do. A good driver controls themselves — imagination included.

I wouldn't especially trust a driver's reaction time in "deep concentration" mode whether or not they were making pictures in their head, so I guess I don't see (ha) a big distinction.

Though actually, for me I find it harder to do mental visualization when there's a lot of real eyball visuals going on, as when driving. I have an easier time with a static background. Perhaps other people are different.

(2) I find that day-dreaming is somewhat voluntary, too. It can happen on its own, but it can also be a choice, like choosing to meditate. I don't understand your point about how someone else's ability to interrupt you makes it non-voluntary.

(3) I didn't mean to say I "see images in front of me." They are actually distinctly not in front of me — not outside my body. They live in a different space, if you will.

99% of people have this ability to visualise. And yeah, it’s crazy that they are allowed to drive!

Isn’t it distracting? Seeing stuff in front of you when you should be looking at the road?

No, because it doesn't happen randomly, it requires concentration and focus. Having random hallucinations is called schizophrenia. Mental visualization is not like that at all.

I thought everyone did. I mean I can just picture whatever I want. A big purple monster with 20 arms? Done. You want him running towards me or away? Now he is upside down. It's as natural as any other thought, to the point I'm sure others either just never taught themselves how to do it or they just interpret their thoughts in a different way from me, or are lying in order to be quirky and "not neurotypical" which is trendy.

Another fun thing is imagining things but not fully. The brain will fill in the spots but not throw you all the info at once. For example I didn't really think of the monsters nose, but now that I did, it has a huge nose piercing like a cow ring. This is great for creation because instead of creating with your foreground brain, you can create for free with your background brain. I'm pretty sure every person can do this (barring <0.01% population health issues).

I'm like this too, and if I want to consider variations I can instantly see rows and columns of whatever I'm considering with variances left, right, up, down, back and in.

I use this extensively when I code too. I can see the lines of code, to the degree I can read them, and I've not found a limit to how much code I can have in my head and visualize at a reading level. I can do this with every single line of code from an animated ray tracer I wrote in C back in '85. Any code that I personally felt proud to have created, given about 5 minutes to recall the details, I can write the code out from memory.

Beyond seeing the lines of code, I see functions and objects and data structures as geometric shapes, and their interactions vary between images of little machines, like airplanes, traveling between them to complex bridge structures like freeways with lot's of traffic.

I'm also a lucid dreamer. I can tell when I'm dreaming with a test: if I say "apple" with my hand held on front of me, palms up and an apple appears which I can then grasp and hold, then I'm dreaming. I'll often wake at that moment, but when I don't I start taking advantage and fly like Neo. Often I'll fly into something, and the jolt wakes me. I wake laughing too.

You had me until the sweeping generalisation. I can picture things clearly but only deep inside my head. I never (awake) see anything in front of my eyes that isn’t physically there.

In normal mode I also do this all in my head, dark background, nothing around it, but if I'm looking at something and want to picture it in a sort of augmented reality you can can just use what you see as the background, but it's still in my mind. I don't think anyone is inducing actual visual hallucinations if they are sober.

that's the point many are making. in your first comment you described exactly a visual hallucination and now you clarify it's nothing like it. it's too subjective that self-reporting becomes useless

You have fallen into the trap of believing that everyone's brain works the same, in that if you have an ability, everyone else must have it or they're lying.

It's funny for me, because I can "visualize" something in a non-visual way. I can transform it and imagine it fitting together with another object, or whatever. However, this is entirely non-visual. I see zero of this in my visual field, it's purely a sensation of seeing it without actually seeing it.

I also have nearly zero dream recall. I know I do dream, because occasionally I will wake up in the right part of my sleep cycle to literally feel the dream dissipating. Sometimes I can remember parts of it as it dissipates, but most of the time I have no clue what I dream after the fact.

There are some surprisingly objective tests for aphantasia - fmri shows it pretty clearly, but also imagining bright things causes iris to change in normal people but not in people with aphantasia.

You could say that aphants just may not be trying enough - there are tests for that as well. But there is hope that in many people aphantasia is something that can be overcome, because it’s just a matter of a lack of a proper skill, or some sort of childhood trauma.

I can not see images in my inner eye most of the time, but I do while dreaming, and I have had a single experience of doing so while meditating, which was clearer than anything I've experienced.

So I have basis for comparison. The difference is sharp and unmistakable.

What is frustrating is that my one experience suggests it ought to be possible for me to train my ability to, but no attempts have succeeded (I've not made that many - it was an interesting experience, and I'd enjoy having it again, but it wasn't earthshattering enough to spend a lot of time on)

I think that means that you have aphantasia? I just asked my wife if she can see the apple and she can, no doubts, she pointed to it and asked what I meant, of course she could see it, she was imagining it and that is what imagining means. I feel like I'm missing out now, I kind of wish I hadn't read the story now.

If it means being able to hallucinate on command, i.e. superimpose the apple in your view as if you were wearing AR glasses, indistinguishable from a real apple apart from your knowledge that it's fake -- then that's a much sharper test and I can confidently say I can't do that. I'd be very surprised if anyone told me they could do that. If it's more of a separate mental plane rather than really seeing it, that's where I think it gets tricky to agree we're describing the same thing.

People can absolutely do that. I'm very close to that myself. I can "see" through walls, for example. If I'm familiar with a room I can describe to you what it would look like from the angle I'm looking at, with the wall deleted.

Do you find drawing easy then, since you could trace around a visualization? That seems like it could be a useful test. I would expect those without aphantasia to be better at contour drawings (e.g. cartoon characters) if it really feels superimposed on normal vision.

I can not see a thing with my minds eye most times (it has happened once) but I can easily sketch out the rooms in my house from a specific vantage point.

All the information is there, not just a visual, so I don't think it'd be a viable test at all.

I think it should work in the other direction though. You might draw well even without mental pictures, but if someone has AR-glasses-style superimposed images but can't trace them on paper, that would seem strange to me.

The limiting factor is the sketching skill, I'm afraid!

No, what you are stating is not what he asked.

> indistinguishable from a real apple

This is like saying what you perceive in your head through the wall is exactly as real, vibrant and tangible as if that wall was actually replaced by a window. Most everybody can describe, or "picture," a familiar room in their head - even from long ago like walking through the house you grew up in - but it is not the same as saying it is indistinguishable from actually being in the room and your eyeballs actually looking at it.

at least in my mind, it feels like there are two different systems for "imagine something" and "see it from this angle". Imagining something sets it into a sort of virtual space, and seeing it from this angle overlays reality with it. It's not a fully realized tangible experience but it's a lot closer than people with less vivid visualization think it is.

My point is not "I can do this", but rather, "I'm close to that, and it's foolish to think the continuum ends where I am."

Memories are also highly fallible, there are many experiments that prove people will rewrite what they did and why they did it and believe the new version of reality fully.

I remember reading somewhere that consciousness is like a public relations manager. It makes sense that highly social creatures that will die if shunned by their tribe would have a complex system for explaining their actions in the most positive light possible.

What is somewhat objective, in a sense, is someone's report of how closely their imagination matches what they see with their eyes.

If you can close your eyes and get your mind to produce something like a photo of an apple, you know it. If you can't even remotely obtain anything like that you know that too.

> When one person says they see 80% clear mental pictures and another person says 10%, how can we be so sure they aren't just describing the same experience differently?

Who uses raw abstract percents? Even the meme version is much more competent than that: https://preview.redd.it/o1lktd5no9t61.jpg?width=640&crop=sma...

I was imagining people saying this in reference to a diagram like that (labelled with percentages instead of 1-5).

It's possible that two people would say numbers like this despite having the same experience and referencing the same diagram, but I would bet that very few people are that bad at interpreting the diagram.

Maybe I am one of those few people :) I don't know how to interpret that diagram. Based on some of the comments here I would put myself at #1, and based on others at #5.

A simpler test. Imagine a ball on a desk.

What color is the ball?

People who are #1 respond immediately, just as if you asked them about a real object in front of them. #4/#5 will ask “what do you mean what’s the color? I can imagine it to be a certain color” - in their head the ball is just an abstract concept labelled “ball”, it doesn’t have a color by itself.

Right?

I literally don't believe that aphantasia meaningfully "exists" given what we've learned about brains. I'm reminded of the great article I saw about how "Your mind is not a computer?" No one remembers "images" in the way a computer does, we (re)construct them via association.

So I think our brains "remember" enough to do what it needs to do and no more, and so called aphantasia people are perhaps doing what subjectively feels like less reconstruction based on what they read.

I’d say this is pretty accurate as someone who considers themselves to have aphantasia. When I remember what apples look like there’s no feeling of reconstruction. It’s just a list of facts. The idea that reconstruction would even be necessary, or part of, remembering things seems surprising to me.

What it practically means? I have no idea. I’m absolutely worse at remembering things like clothes someone left the house in but that could also just be me paying less attention to things like that.

When I realized I have aphantasia and told my wife, she said that makes total sense. For example, when imagining how a piece of clothing looks on someone, she can take it, put it on someone, change the color even. All those things sound ridiculous to me.

I'm using "reconstruction" loosely here. What I'm trying to describe is the process that our brains use to think about ANYTHING and why it's nothing at all like how computers reread a series of ones and zeros.

I have once seen clear mental images, but consider myself to have aphantasia because I've only experienced that once.

I also have mental images while dreaming, but not so clear, that persist for short periods as I'm aware I'm waking up.

The three experiences are nothing remotely alike.

The difference between "10% clear and 80% clear" may be subjective, but when people assert with complete conviction they cannot see anything in their mind and cannot even picture their own parents, I can be confident that their experience is not like mine.

I suspect it probably could be if they practiced, maybe picked up an artistic hobby or two, but if they're insist they're not visualizing presently then I'll believe them.

Comparing subjective experience is ultimately futile. That said, humans can be very similar beings to each other, and perhaps similar enough that we can communicate a enough for a useful (if very lossy) comparison.

The key here is to remember that what makes us capable of sharing a world view and understanding each other is not just speaking the same language, there is also a degree of required shared cultural background—and it is not shared by all humans or even just speakers of a language.

In order to make sure a question about inner experience yields a useful answer at all from person on Earth who has a sufficiently different life from yours, you may first need to establish a common world view basis of sorts (unlikely to happen in, for example, a mass survey, but perhaps possible in a long-form discussion on an online forum).

Of course, even after all that, any comparison will still necessarily be very low fidelity.

Low fidelity information transmission is not "ultimately futile" but instead something to build on. Or what do you measure it against?

It is ultimately futile for the reasons outlined in the top-level comment. What one person experiences cannot be precisely conveyed to another person without round-tripping very lossy means of communication, such as language.

If you have an example of some existing means of lossless communication between two humans, bring it forth. If you believe it is a technical possibility, then be my guest—however, I do not see such a way (that would also maintain humans as a set of diverse individual conscious agents, so homogenizing society to reduce everyone to a shared baseline does not count).

Absolutely everything we have achieved as a civilization, depended on lossy communication between humans. And all experience is inherently subjective. Why is all that somehow ultimately futile and requires counterexample not to be? I don't get it. We don't have to totally understand each other to achieve something together.

What is futile is to fully communicate experience. You seem to be talking about something else. Yes, individuals having or not having aphantasia, me being unable to communicate whether my blue feels the same as your blue, etc., does not prevent us from achieving certain goals together.

I agree completely. No one has access to another's mental state.

When you think of linguistics, and commonly misunderstood terms even though we have an objective way to convey the meaning (dictionaries, words) eg 'emigrate', how many more misunderstandings are possible when there is no objective access?

Apt comment. I was sitting here thinking to myself, "Do I see mental images often? At all? Yes I think I do... But is it less than others? Or about normal? How would I know?"

Also, I think people who say they have no inner monologue think an inner monologue is like JD on Scrubs thinking to himself.

To me, my inner monologue is like that, and it is constant, every waking moment unless I make conscious efforts to suppress it, like while meditating.

As for mental images, I have them all the time while dreaming, but I've only experienced them once in my life while fully awake, and profoundly clearer than any dream. I can remember what some of the images in a few dreams looked like, but once I start waking up, the visuals fade within 30 seconds or so of being aware.

whether your experience of red and green is the same as mine or swapped.

God this is a tired argument. Your visual cortex is not special. Your red isn't any more different from my red than my "circular" is different from your "circular".

It's a well known thought experiment: https://plato.stanford.edu/entries/qualia-inverted/. I'm not arguing for or against it being true.

>God this is a tired argument.

We literally can't know, and never will. The fact that you assert that assert otherwise (as far as I can tell) with such staunch confidence seems to be exactly the kind of thing OP is calling into question.

Misconceptions about subjective experiences often stem from a narrow view of what constitutes internal perception. The very nature of subjectivity means that each person's internal process is unique to them. It's erroneous to insist that we must "see" something as if it's physically present for it to count as a subjective experience.

From the article: "but somehow they cannot integrate this information in a subjective experience".

Consider a conversation with a blind person. Claiming they aren't having a subjective experience because they can't visually perceive you would be fundamentally biased. Clearly, one doesn't need visual input to engage in meaningful interaction or to have rich internal experiences.

Over time, it's become clear that people have a wide range of internal experiences. While individuals often try to compare their experiences to some imagined baseline, this baseline itself is subjective and variable. Many mistakenly assume that their own subjective experience is universal or "correct," failing to recognize the vast diversity of internal processes across different people.

Recognizing this diversity is crucial. It helps us understand that subjective experiences can vary greatly between individuals, yet all are equally valid. This broader understanding moves us away from judging others' internal experiences based on our own limited perspective, and towards appreciating the rich tapestry of human cognition and perception.

I remember reading that some inventors could form mental images accurate / with enough fidelity to visualize complex machinery interacting. In architecture school there was gradient in how well people could mentally visualize spatial relationships including measurements. I remember a project on a fairly narrow site and during initial sketch exercises, people were coming up with (to me), obviously unworkable solutions because the programming (i.e. rooms) they'd need to fit into certain volumes, couldn't. Spectrum in spatial visualization becomes very obvious when you see tacticle / visual learners iterate through a bunch of designs, whether with modelling or with CAD, and after a few lines, I (and some others) knew immediately the proportions / scale was wrong. Became very obvious when projects started incorporating building codes and designs needed to account for required # egress (fire exists etc) XYZ meters from any point in floor plan. Some people can mentally iterate through designs/measurements in their heads, some people have to draw things out to figure out.

For what it's worth this is believed to be a measurable skill sometimes referred to as "spatial reasoning"

You doubt that people can talk objectively and confidently about this, but then it seems like you conclude (implicitly or not) that we should therefore stick to the default of assuming everyone's experience is the same (and therefore the same as yours, btw). Alternatively you could take the difficulty of communication as a sign that we have at least just that much leeway concerning the difference between each others' experience.

You are skeptical when people say they have an internal monologue. Those without internal monologue would be skeptical when you say you do have an internal monologue. Your confidence is also based on nothing more than your personal experience + bias.

PS I firmly doubt those "swapped colour experience" ideas make any sense at all. Probably the thing that is assumed to be flipped is just that part of the experience that only seems to exist as an absolute, yet is actually not defined at all beyond its relations to other experiences.

I wasn't trying to convey that conclusion. I'm skeptical at people's confidence; I'm not confident that they're wrong. I think they discount how big a factor the difficulty in communication is.

On internal monologue, I said the opposite. I'm skeptical when people say things like "I also don't have an internal monologue. I don't passively think thoughts. I have to actively think everything."[1] I have a reason for this beyond personal experience and bias: that it's easy to be shockingly wrong in this direction. For example, many people will think they can count 60 breaths without being distracted by thoughts, only to find it impossible when they try and pay close attention.

Maybe the swapped color was a bad example. I just mean any direct comparison of qualia in different minds which is impossible to do, and therefore pointless to talk about.

[1] The first Reddit post I found searching for "no inner monologue"

I dunno. I can hear music, it is muted in my brain but I basically have a audiographic memory. I can't visualize anything though. It is so weird. Basically my internal DNN can record and playback but not yet generate new things like stable diffusion either.. I suspect my musical training at a young age played a role in this as well as listening to lots of classical music.

Psychologists and neuroscientists can tease these things apart.. in the article they talk about it. But aphantasia is only recently being understood so methods to quantify the degree will improve.

Although not truly the point... we do know that people don't seen red and green flipped because color's don't work in isolation. It's also how they work together. If a person with flipped red/green mixed what they saw as red (actually green) with blue, they wouldn't get purple.

We could suppose that someone could see the entire spectrum inverted, but that causes other problems that we could test for. There are more hues between red and blue than there are between green and yellow. Instead of seeing brown (really dark yellow), they'd see dark blue.

The point he's making is that colors do not "really" exist - they're simply different levels of energy on the electromagnetic spectrum. How we perceive those colors is exclusively a product of our brain using input filtering from our eyes and then converting this into signals that we then perceive. But there's no reason to think that this processing and filtering eventually results in the exact same perceived color for every person. My red, blue, and purple could all be perceived simply differently than yours - even though every physical law interacting with what we perceive as color would behave identically.

And the even more interesting thing is that this nuance of reality extends to everything. The world as we perceive is only after extensive processing and filtering by our brain, driven by millennia of evolution. And it's very safe to say that our perception of the world has changed over those millennia and will continue to change in the future. So it seems essentially illogical to then assume that everybody at the current time shares the exact same 'experience' of perception.

Yeah by "my red" I'm talking about qualia as in the knowledge argument https://plato.stanford.edu/entries/qualia-knowledge/

You're just introducing more and compound things that we don't know if we have the same experience of.

Consider an enum type: we agree on labels (colour names) for different stimuli; as those stimuli combine they correspond to some other enum variant, and we interpret them as the same label. But we don't know, and I agree with the top-level comment that we can't know, whether our perception of the stimuli with that label is the same.

This is distinct from colourblindness, which is inability to distinguish stimuli for some of the enum variants, and so the labels get merged/boundaries between labels move. (Ok fine we also need a hashmap from stimuli to the enum..)

We agree to call the rose pink, and it's the same pink we see when we look at a colour card and agree it's the colour of the rose, but we don't know that what our brains reconstruct from the light when we look at 'pink'-labelled things is the same.

> how people talk so objectively and confidently about this

I can visualise things in my head exactly the same as someone with their eyeballs removed can see real things.

I think that's relatively objective.

And I say this with confidence.

There are billions of people who have claimed with absolute confidence that they can talk to the disembodied spirit of a man who was nailed to a tree two thousand years ago, and that this is objective fact.

Apparently, you can know by how you recall a memory. Do you "see" it as a film? Or, do you recall it as a list of facts?

There's more than that going on. There's recall, but there's also constructing counterfactuals and extrapolating from existing detail.

"where did I leave my keys", "what would it look like if I moved that couch", and "how big is the room I can only see one wall of", are decent examples.

Not to be that guy, but the article discusses this at some length. Find this bit:

> However, such tests rely on introspection and self-reported experience, which made some neuroscientists doubt that aphantasia was real. Could reported differences in visual imagery be a language disconnect, given the ambiguity in how we describe our inner worlds? “It could be the case that we’re all actually experiencing the exact same apple, we’re just describing it differently,” said Rebecca Keogh, a research fellow in cognitive neuroscience...

The following ~8 paragraphs discuss the evidence for it beyond subjective reports.

I'm not entirely convinced by it. But even if I was, I'd still stand by my claim that many people speak about this with unwarranted confidence. This comment thread has lots of people who seem to know for sure that they do/don't have it, and also several definitions such that I could easily self-diagnose in either direction by picking the right one.

Mental Images (of things) 1/10, Inner Voice 9/10 (reading)

So these are be relative to what i see with my open eyes and hear with my ears. I think this is the only way you can measure.

(What i see vividly with eyes shut is more like something random a kalidescope.)

Pretty much this. For further consideration it may be worth looking into Daniel Dennett's writing on qualia (notably that they're ineffable and private).

You've put into words how I've always felt about this as well.

It is not at all difficult to understand that I’m “hearing” my thoughts and imagined sounds

It would be unfathomable for me to have this experience and not acknowledge that my mind is simulating sound

fMRI is mentioned in the article several times.

Yeah, I have the same feelings when I read these articles. For example:

"Behind her eyes, it was completely black” "They reported actually seeing an apple, some vividly and some faintly"

This seems weird, but both of these describe my subjective experience of imagining an apple equally well.

> There are subjective things we'll never able to compare

It's certainly difficult to perfectly compare qualia in absolute terms across minds. It's less difficult to compare qualia within the same mind. And if one person reports they experience two things equivalently, and another person reports they experience two things incredibly differently... it's hard to claim the two people must be experiencing the world equivallently.

Some people hallucinate through drugs or mental illness, and find themselves unable to distinguish said hallucinations from reality. If only one of us sees the pink elephant tap dancing in the middle of the room... it's likely that one person is hallucinating.

Some people dream vividly, to the point where they can't always immediately discern if a memory was from when they were awake or when they were asleep. I have had such dreams. Others are able to identify specific diminished senses that they were able to use to immediately distinguish the dream from reality. I have had such dreams.

Some people are able to visualize scenes and describe them in far greater detail than I ever could from mere imagination, which helps back up their claims to being able to effectively vividly hallucinate/dream at-will in ways I've never accomplished.

> I could say I see it clearly or not at all depending on what you mean by seeing.

I can see an apple in reality.

I can see an apple in vivid dreams.

I could presumably see an apple if I ever hallucinated one.

I cannot in good conscious say I can "see" an apple through visualization alone without a great deal of effort to get an incredibly mediocre result that even a toddler's enthusiastic and proud parents would have qualms about pinning to the fridge.

Some people will be able to go into immediate detail about the color and texture of the apple they have a specific concrete memory of imagining years ago. Others, such as myself, will readily admit they completely forgot to even consider that the apple they're trying to imagine might have colors, even as they try to imagine it. Red? Green? A rainbow mac apple logo with a bite out of it? ...and you say this thing is supposed to have lighting from a direction and cast shadows?!? I can barely imagine a circle! Give me a break! And maybe some dice, so I can decide on a color to attempt to imagine! ...I think it's fairly safe to say that those two experiences are at least marginally different.

Reply on news.ycombinator.com