Aphantasia is just the tip of the iceberg - there's a whole laundry list of 'abnormal is normal' mental stuff out there.
A partial list: they vary from the various kinds of color blindness to anosmia (unable to smell!) to blind people regularly having vivid visual hallucinations (Charles Bonnet syndrome) to hearing voices (something like 10-20% of people occasionally hear voices) to lack of inner monologue to musical anhedonia (being unable to enjoy or be moved by music) to ASMR to misophonia to the nasal dilation cycle to 'intrusive thoughts' like 'the call of the void' to hypnagogia (hallucinations while falling asleep) to being aware of one's facial expression when talking to synesthesia to faceblindness to crying (I was shocked to learn that many women report shedding physical tears from sorrow on a weekly or monthly basis) to repetitive PTSD-like school dreams to long-running elaborate daydreams ('maladaptive daydreaming')...
(There's also the funny little lifestyle ones. Like, do you take shoes off or not? Do you take 'navy showers' or let the water run the entire time? Cereal then milk or vice-versa? Do you eat the same thing for lunch every day?)
Interesting that you put specifically “being aware of ones facial expressions when talking” as one of these quirks. I definitely have that, but thought it was related to the autism. I wonder how many of these quirks might just be effects of being just on the cusp of AS.
One of the things that nags me about such an inventory is how “good” it is in the sense of promoting happiness. I’m perfectly content with my quirks, in fact talking it over with my girlfriend I’m starting to think that it might explain my excellent explicit memory(fwiw I feel I have a weak implicit memory) But reading through the thread, there are a number of people who are upset, feeling like they have lost out on something precious. I guess without guidance as to how these things can be leveraged as a strength, I’m not sure I see the utility in highlighting these cognitive differences. In the same vein as studying the differences in race or gender. Not that I don’t find them extremely interesting to think about.
Prosopagnosia and misophonia are interesting, prosopagnosia both in terms of recognition but also how it affects sexuality (think demisexuality), and misophonia both in terms of existence and what pitches people find intolerable.
Aphantasia is also interesting in that there's a visual form and an auditory form, and my preliminary survey results show a large correlation with autism for the visual but none for auditory. More generally, it's also interesting how it interacts with things like depression, anxiety, and mindfulness as well as things like DP/DR.
I became interested in sensory differences because I do not feel hunger or cold (more common than you'd think, interoception differences), and then discovered I have aphantasia back before it had a name, but also have CEV of at least level 4 and can conjure it up with effort just by closing my eyes which is apparently far from the norm.
I have a suspicion quite a lot of revealing stuff has been written throughout history on these things, just with the author assuming everyone's like them. To take CEV as an example, Jung's "active imagination" as described in the Red Book sounds a lot like CEV level 4, and also resembles how some people describe shamanic journeys. I can also see how maladaptive daydreaming can start off slowly, lead to a paracosm before ending up with Gondor.
Gwern, bit of a tangent but I think actually related: have you by chance looked into thought loops at all? Obviously there's the psychdelic variety, but I'm also thinking of those described by sufferers of anxiety, depression, and especially anorexia.
> repetitive PTSD-like school dreams
I'd really like to know how common this is. I'm now almost ten years removed from my school years, but the vast majority (90%+) of my dreams are based there.
If I'm not "seeing" something, I'm "hearing" it.
If I want to think about sound, I hear it.
If I want to think about an image, I see it.
But if I "just" think a thought, it doesn't have a form like a video, audio or text; it's just ... I don't know ... an amorphous idea?
It is an important concept in the philosophy of mind.
To my surprise, a lot of them said they don't really think in a language or voice.
I've got a King Arthur's damn round table up there having a roiling debate most of the time (not the norm), but I was surprised that so many people don't really have any sort of representation or "source" from which internal ideas originate.
I'm Norwegian, but have lived in the UK for 19 years.
I find myself switching languages mentally all the time. My "voice" is different, and when I think in English, I think with an accent even though I don't really "hear" my voice when I think (it is very strongly distinct from sound).