[leche]

I have (self-diagnosed) aphantasia and SDAM. I do not relate to your belief that SDAM is related to the emotions felt. I don't believe I have ADHD nor autism. We don't currently have a scientific understanding of the mechanisms that cause these differences in experience, so everyone forms their own ideas of what's going on based on their own grab-bag of internal experiences and qualia.

[sReinwald]

That's fair criticism, I'm obviously coming at this from my personal perspective and that is shaped by how my brain experiences the world. I should've been more precise, I didn't intend to suggest that alexithymia is the only pathway to SDAM, there are likely multiple aspects or pathways that can contribute to or cause it.

However, I would challenge the premise that SDAM is entirely unrelated to emotional processing. It's important to distinguish between the conscious feeling of an emotion and its subconscious role in the mechanics of memory formation. There's significant evidence that emotional salience is a crucial part of how the brain tags and consolidates strong autobiographical memories. A disruption to this process doesn't have to be a consciously felt emotional deficit; it can be a mechanical one operating below the level of awareness.

We can look at this as two distinct points of failure in the memory pipeline:

Failure at the input stage: If the emotional signal required to "tag" an event as important for rich autobiographical encoding is never met, the memory is formed, but only as a semantic fact ("a thing that happened"), not a re-experiencable episode. The processing can't happen because the right input was never provided.

Failure at the retrieval and re-experiencing stage: For someone with aphantasia but no issues with alexithymia (like you, I'd assume), the initial emotional tagging might function perfectly well. The disruption happens later. The core deficit of SDAM is the inability to "mentally time travel" and re-experience the past. Aphantasia, by definition, removes a primary tool for this: visual imagination. The brain processes and integrates emotions by revisiting them. If you cannot truly "re-live" a moment because the visual data is inaccessible, then the episodic, first-person quality is lost.

This second point matters beyond just losing access to nostalgia. We process and regulate emotions by mentally revisiting experiences, integrating them into our broader life narrative. If you have greater difficulty "re-living" moments of joy, achievement, or connection because you lack the tool of visual imagination, your ability to extract meaning from them and build emotional understanding is compromised.

Both mechanisms effectively lead to the same subjective experience: a past that feels like "someone else's life" that you know facts about but can't emotionally (re)connect with. The specific pathway might vary between individuals, but I now strongly believe that the underlying issue remains the disrupted relationship between emotional processing and autobiographical memory formation.

Does this potential explanation align more with your personal experience?

I might have to spend some time over the long weekend to explore this a bit more, and to properly back it up with studies.

[leche]

Thanks for the follow-up. I find this stuff quite interesting.

I feel my emotions strongly as I live through them(as much as one can say, we can't feel others' feelings), but feel them not at all when I relive them (because I cannot relive them). My emotions are a guide for me, but after the initial feeling of them, they guide me semantically (why was I feeling anger during a particular conversation? maybe I need to reconsider my position).

Incidentally, I generally think of this as being able to "let go" of emotions/grudges/etc that I might otherwise spend unnecessary time worrying over. It does set me up for being an "especially boilable frog" in that I can quickly acclimate to conditions that others might have trouble with.