I had what I would describe as a 90% version of this for the longest time. My mental imagery was mostly <i>ephemeral</i> to the point that it may as well have not existed—attempting to picture something would give me a mental &#x27;flash&#x27; of it, that would then instantly be replaced with darkness. Nothing would stick around long enough to permit examination.<p>I discovered one &#x27;trick&#x27; to get around this: certain music would cause strong, evocative &quot;music video&quot; imagery to be conjured in my mind&#x27;s eye for as long as I listened to it, with this being mostly directible (i.e. the emotional cues of the song were fixed, but I could constrain the imagery to anything that matched those emotional beats.) I considered myself a writer in my teenage years because I took advantage of those &quot;synesthetic fantasias&quot; to build up scenes and characters in a sci-fi setting of my own creation. Sadly, this ability faded with age.<p>More recently, I was diagnosed with Inattentive-type ADHD (and, to be clear, it was always there, rather than adult-onset; my parents just disregarded the advice of my family doctor and pretended I was neurotypical.) I began taking medication for it. My visual imagery is <i>not</i> ephemeral any more! I mean, it still kind of is, insofar as mental images will be lost the moment I temporarily lose focus on them—but I can now hold the images for as long as I concentrate on them.<p>I think I might now actually have access to the full &quot;thought toolset&quot; other people do, but since I developed and rely on this alternate way to go about thinking without it, I don&#x27;t reach for visually-imagining as a way to do things, so it doesn&#x27;t get used often.<p>On the other hand, I notice that, on ADHD medication, I have far fewer fleeting &quot;unrequested&quot; visual images. I can now imagine <i>consciously</i>, but it seems like the visualization capabilities of my <i>subconscious</i> have been switched entirely off.<p>Though, I do notice, if I go a day without taking my ADHD meds, the <i>second</i> night—when it&#x27;s all washed out of my system, but my brain hasn&#x27;t bounced back to producing any dopamine, so the amount in there is even lower than my baseline—I&#x27;ll have really <i>intense</i> dreams, where the details of every scene are full of &quot;grotesquely real&quot; imagery, as if DeepDream were trained on Zdzisław Beksiński paintings.<p>This almost makes me wonder whether there&#x27;s a sort of &quot;cross-fade&quot; potential between conscious and subconscious visualizing, controlled by dopamine. Really low dopamine: vivid dreams, no conscious visualizing. Average dopamine: meh dreams, meh visualizing. High dopamine: no dreams, vivid visualizing. (This would also fit with the observation that <i>visual hallucinations</i> are a symptom of mania.)