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That's pretty much what my therapist said when I first expressed this to him, so you're in good company there. I thought about this more on my commute home fro

That's pretty much what my therapist said when I first expressed this to him, so you're in good company there. I thought about this more on my commute home from work, and I'm starting to suspect that "SDAM" might essentially be the long-term effects of alexithymia or interoceptive blind spots, which are fairly common in neurodivergent people with ADHD, autism, or both. For context, alexithymia is a significant difficulty in recognizing, sourcing, and describing one's own emotions. Interoception is the sense of your internal bodily state. You can likely relate to being so deep in a flow state that you don't notice how badly you need to use the restroom, or how hungry you are, until the feeling becomes so overwhelming it finally breaks through your focus. That's an interoceptive blind spot in action. So, to further elaborate on my theory: If alexithymia raises the required signal strength for an emotion to be consciously recognized as significant, our brains - which strive for efficiency - will only tag and store memories that cross that unusually high threshold of "important." All the "little things," even the nice ones, get dropped because they never registered with enough emotional weight at the moment they happened. The brain prioritizes emotionally significant information for memory storage. If an event doesn't trigger a sufficiently strong or clearly identifiable emotional response at the moment it occurs - because your baseline emotional processing is affected - it might get stored as just factual information rather than a rich, emotionally resonant autobiographical memory. It becomes "a thing that happened" rather than an "experience I had that affected me emotionally." This explains my memory pattern perfectly: I remember most big family holidays - Christmas, birthdays, weddings - because those come with heightened emotional anticipation and distinct social components. But I'm already struggling to piece together what we did on Easter this year, and have absolutely no idea what we did last year. The quieter, more routine positive events apparently don't meet that higher "emotional importance" threshold for deep encoding. It's like having a filter that's calibrated too conservatively - it's protecting you from information overload. Perhaps that's why it's so common in neurodivergent people, both ADHD and autism heavily affect how we take in and process external sensations. If there's any positive spin to this theory, that I will agree with you, makes sense in a not good way, it might be that. But, unfortunately, it's also discarding experiences that others would naturally encode as meaningful memories.

leche 1y ago
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 1y ago
  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 1y ago

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 1y ago
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.