Speaking from experience as an aphantasic person, I think it is definitely possible to test objectively. For instance certain IQ tests will test the subject's ability to identify what a pictured object would look like if it were rotated in a certain way.
I have taken just such a test where spatial rotations, IIRC including multi-step ones, were a component, and I scored close to 99th percentile on every section except that one... where I scored 1st percentile. If that's not a strong sign of aphantasia I don't know what is!
This is actually one of the things about aphantasia that has already had a (small) study[0], and the results are actually the opposite! The participants with aphantasia were more likely to both (a) take longer to answer and (b) be _correct_.
I personally have aphantasia and have quite good spatial reasoning, including with mentally rotating objects. I think it's fair to assume that visualization and spatial reasoning are mostly (but not entirely) orthogonal spectra, and it's completely possible for people to fall anywhere on either, just based on how their brain developed its internal strategies throughout normal life.
Yes, objective tests must somehow take into account the multitude of coping mechanisms that people with the condition have developed. "Spatial reasoning" for example is very close to logical reasoning, and I don't see why people with Aphantasia shouldn't be very good at that, albeit slower in "spatial" mode.
I don't read a lot of full-length books in recent years generally, but as a child I read tons of fiction... I was about to say "...so I don't think I have any trouble," but actually, come to think of it, most of the books I liked as a child were things like Redwall or Warriors, where all the characters were distinct species of animals and things like that.
If the characters are all humans, I think it's difficult to remember who's who because they're just random collections of syllables (names) tied to a set of facts — "Kirk, a human man, is a captain", etc. I think, though, that this may be more of an aphantasia/faceblindness thing (I have no "theater of the mind" and can't picture characters to distinguish them) than an autobiographical memory thing.
On the subject of memory, I will say, though, that perhaps I lack an interest in fiction books nowadays because no fond memories of reading them stick with me; even though I can recount the plot in excruciating detail, the most I might be able to say after the fact is "I liked/disliked that book" in a general sense, and that's just a memorized fact about my immediate feeling at the time. With a nonfiction book on the other hand I acquire information that can be useful to me afterwards.
My understanding is that most people remember past events in the context of their own experience of those events — when they remember, they recall into their minds some version of what they felt/saw/heard at the time, re-experienced from their own perspective. I've heard some people describe it like replaying a film, and they may even get a portion of the original emotional or sensory experience with it. I have none of that at all.
I'm thinking of a happy childhood memory. I'm with my grandmother down by the lake. We're getting into a boat.
I can see the way the sunlight reflects on the sand in the shallow water and off the oars in the boat (and what their flaking varnish feels like in my hands). The smell of the reeds, grass, and lake water is very clear to me, as is the voice of my grandmother telling me to be careful to not fall into the water. I can also hear a lawnmower somewhere in the distance, kids splashing around by the beach, and rustling of the reeds as they're caught by the wind.
It makes me happy, but also nostalgic. Most of the things from this memory are gone now. I believe the English word that best describes this is "wistful".
I know memories are peculiar and that parts of this memory are probably borrowed from other memories, or even made up, but it doesn't make it feel less vivid to me.
Yes, quite. They can be affected by the kind of tunnel vision you get when you're very stressed out. Like remembering a spot on the wallpaper, or a brass part of the handrails on the stairs where my parents gave me some bad news when I was four.
Unfortunately I can't seem to decide what sticks and what doesn't. I don't have perfect recall (far from it). I can barely remember what I had for dinner yesterday, but if I do I can probably still taste it.
Yes, but I think there's something even worse: things that haven't happened.
Anxiety is kicked in to overdrive when you can vividly imagine adverse outcomes to such a degree that they are indistinguishable from things that have happened.
Not parent, but it sounds like I have a very similar neurotype — I am also autistic, aphantasic (I scored <1st percentile on the spatial-manipulation-in-your-head part of an IQ test at one point!), and have no autobiographical memory.
The best way I can explain the latter, at least in my own experience, is that I have no first-person memory of events I've experienced, but I still know the "bullet points" of what happened: the raw facts, if you will. It's like if another person experienced my life on my behalf and gave me a daily summary; I know that a set of events happened, but I feel no personal connection to them and don't recall them in any more detail than e.g. information I've read out of a textbook (often less). I can easily recall other information, not associated with time/place/experience, with higher-than-average accuracy, but accessing personal-history-type memories takes a lot of conscious thought. There seem to be some rare exceptions for memories that are tied to extremely intense emotional or physical experiences, both positive and negative, but even then the memories are fairly weak/fuzzy.
This has some funny side effects, for instance, innocuous small-talk questions like "what did you have for dinner yesterday" basically cause me to segfault because recalling information like that (plus the autistic compulsion to answer accurately) requires extreme cognitive effort. I also lack the ability to "miss" people because I have little to no personal memory of what it was like to have them around.
In short, it can be socially inconvenient, but doesn't affect daily functioning.
I'm undiagnosed but personally I suspect I am autistic. I have hyperphantasia + eidetic memory, but I have periods of my life (years) with almost no autobiographical memory. The tape is blank or the index has been lost, or I was just too lost in thought to lay down any record what was going on around me. Mostly before the age of 12; I can access only a few disconnected moments out of time.
I was moved to tears when I used Google Street View to explore streets of a city that I know factually my father and I had walked through extensively, but I couldn't recognize a single thing or feel any personal familiarity with it. It's hard to explain why that upset me so much.
I suspect most humans are like that, to varying degrees, and in various aspects.
As a random example, a co-worker showed me his very expensive fountain pen. That prompted a memory -- after having completely forgotten for at least twenty years -- that in high school I exclusively used cartridge-based fountain pens! That aspect of my life just *poof* vanished from my memory when I switched to felt-tip pens, and was suddenly swapped back in from an archive tape when I saw a fountain pen in front of me.
This wasn't a small detail of my life! My father got me those pens. They were German-made and he was very proud that he found them at absurdly low prices at a garage sale compared to their real value. I had to buy the cartridges, and they were hard to find. I had a special resealable container to contain leaks. I was proud of the dramatic improvement in penmanship this enabled. Etc, etc...
Just gone. Absolutely vanished. If you had asked me randomly if I ever used fountain pens, I would have said "no". It wasn't until I physically picked one up that it all came flooding back.
PS: I remember maybe a dozen things about my childhood apartment and its surrounds that I grew up in. Don't feel bad!
That's very interesting, thanks for clarifying, I'll probably remember your testimony for the rest of my life. Could you please answer some more questions: Is losing autobiographical memory inmediate, or could you remember a few seconds of what you see? Can you think in other languages? Can you learn patterns like chess moves? What is your oldest memory? Can you foresee events, like an accident about to happen? Do you have olfactory memory? Do you like any kind of puzzles? Can you follow or find things with a map?
I have a weak autobiographical memory as well. The only thing people like this have in common is that they have trouble remembering things they've done. In other ways they differ. The people's personalities are heterogenous, just as in any other group. You can look at the subreddit r/SDAM if you're curious, although it tends to attract whiners. Celebrities who have memories like this include Frankie Muniz ("Malcolm in the Middle") and Courtney Cox ("Friends"). Frankie Muniz has done some interviews about it and you can find those on YouTube.
> Is losing autobiographical memory inmediate, or could you remember a few seconds of what you see?
It's not that I "lose" memories per se, I think I just don't store them in terms of personal experience in the first place. There's no "buffer" in which I have normal autobiographical memory even in the short term.
I have very good short term memory. So for instance I have taken one of those kinds of tests where I'm shown an increasingly long sequence of things and I have to recall them in order — I perform extremely well on that — but the only data I "store" is the fact of what the sequence is, not anything about what it felt like sitting in the room being shown the cards, what emotional state I was in at the time, etc.
> Can you think in other languages?
Yes. My native language is English and I am fluent in Chinese. My husband speaks only Chinese, so between home/work/friends I speak about 50/50 of each regularly. My internal monologue switches between the two languages based on who I'm talking to and what topic I'm thinking about (usually related to which language I encountered it in first).
> Can you learn patterns like chess moves?
Yes, but I tend to recall patterns like that as a verbal description of the sequence, not a visualization. I think I am not fully aphantasic, but 95% or so. If I concentrate, I can imagine something as simple as "two squares up, one to the side" for a knight move for example; the very rough shape of a pawn, rook, etc., but I can only "summon" tiny pieces of each such thing into my mind at a time, almost like looking through a very blurry spyglass at maximum magnification. E.g. trying to imagine a pawn from top to bottom goes "circle, horizontally flat trapezoid, long vertical trapezoid, roundish base of some kind?".
> What is your oldest memory?
If by "memory" you mean something approximating a regular person's sensory-memory and not just a fact about a thing that happened, probably two days, and it's only an extremely vague/blurry still-frame or two from a moment that just so happened to be among the most emotionally charged I've experienced within the last ~year.
I have literally zero memories of being a child, for instance.
> Can you foresee events, like an accident about to happen?
I can anticipate them by logical inference, if that's what you mean, but I can't "see" them in my mind's eye or anything like that.
> Do you have olfactory memory?
None whatsoever. None for taste either. I do however have extremely good recall for music — e.g. I can "replay" an orchestral piece with multiple parts with reasonably high fidelity in my head — but not for non-musical sounds.
> Do you like any kind of puzzles?
I've never had any interest in visual puzzles, but I like verbal/logic related ones.
> Can you follow or find things with a map?
Only so long as (a) I'm pretty much constantly looking at the map and (b) the map's orientation is aligned with the terrain around me. For instance if I'm a passenger in a car looking at a standard "north-is-up" oriented road map, but the car is driving east and I'm trying to navigate, it is quite exhausting, figuring out each turn takes at least several seconds of full concentration, and I am likely to make many errors.
I'm neither of the earlier posters but can relate since I have both aphantasia and SDAM (severely deficient autobiographical memory). In the current literature these are thought of as distinct things that often co-occur.
> Is losing autobiographical memory immediate, or could you remember a few seconds of what you see?
It's hard to describe this precisely. The visual memory is not lost; it is never formed in the first place. For example, immediately after talking to a person I wouldn't be able to tell the colour of their eyes unless I specifically noted and remembered it as a fact (articulated in my head using language).
> Can you think in other languages?
Yes, I speak multiple languages and do think and dream[1] in most of them. I love learning languages and have been told on many occasions that I'm pretty good at it. It's hard to say to what exent it's due to intrinsic motivation (to me, learning a language is like solving a good puzzle, and I love puzzles) and to what extent it's about aptitude (e.g. the ability to spot patterns, both within a language and across languages).
[1] Based on the literature, it seems that some people with aphantasia have visual dreams and some do not. I do, and very occasionally have fleeing visual imagery when I'm sort-of awake but am either falling asleep or waking up.
> Can you learn patterns like chess moves?
Yes, easily. My brain is very good at spotting and remembering patterns (it just can't visualise them, in the sense that I'm guessing you mean when you talk about chess).
> What is your oldest memory?
I remember a handful of disjoint bits from my childhood, though as facts rather than as images.
> Can you suppose future events, like an accident about to happen?
Yeah, sure. In fact, I have a natural tendency to calculate everything a few steps ahead, probably more than is healthy. At the same time, I have had more than my fair share of personal accidents, but that probably has mostly to do with the fact that I do lots of sports and really like to push my physical boundaries.
> Do you have olfactory memory?
Not really. I can't even describe tastes or smells, except when they strongly remind me of something specific, e.g. some other thing that has a very distinctive smell. I can't even imagine what remembering tastes or smells would be like. After all, it took me more than 40 years to figure out that, when people spoke of visualising stuff, it wasn't just some figure of speech. :)
> Do you like any kind of puzzles?
LOVE puzzles. All sorts. Bring 'em on! :)
> Can you follow or find thing with a map?
Yes, easily. I use topo maps in the mountains all the time, have done a bit of orienteering etc. Correlating the two things that are in front of me -- the map and the terrain -- doesn't seem to require me to visualise anything.
If you're curious to learn more about SDAM, here are some links that I found interesting. The first author's account reasonates a great deal with my experience (though some aspects do differ a fair bit).
I have taken just such a test where spatial rotations, IIRC including multi-step ones, were a component, and I scored close to 99th percentile on every section except that one... where I scored 1st percentile. If that's not a strong sign of aphantasia I don't know what is!