If you take enough acid, it can become incredibly difficult to perceive the passage of time with eyes closed. On one of my higher doses, I was in such an uncomfortable state of mental agitation, fetal position under my covers, that I tried killing time by playing a game of pretending hours were passing when I closed my eyes, and I could briefly believe it until an external sound clued me back in.
Changes in spatial perception might also explain some mental visions, like truly massive scale structures that are hard to imagine when sober, but those incidents aren't as profound on acid in my experience, and you don't see them visually. They're more high-definition thoughts.
This all makes so much sense, because I (having never done drugs) have a constellation of perceptual issues which all relate to this. I believe I have a congenital mutation in these kinds of beat-tracking and spatial orienting cells (it runs in my family). My mother (who grew up in the 60s) always says, of the few times she tried these substances, "Why would you take something to feel this way? I can experience these things normally, I wish I could take something to not be like this."
My main thing is with time; in the absence of other people / external factors forcing me to be synchronized, my subjective sense of time is "wibbly wobbly timey wimey stuff". That is, I might subjectively experience a few minutes as if it is a very long time (like the subconscious dimension in Inception) or conversely I might be doing a task and think only a minute passed and it was an hour.
Sometimes when I close my eyes I experience a sense being an ant in a tiny room versus being the size of Galactus in a solar system sized room, and then warping back and forth like looking backwards through a telescope. That is, the relative scaled distances remain the same but the subjective sense of absolute scale starts to oscillate.
I have amazing visualization skills for reasoning about spaces and machines that I'm not inside of, it's like a CAD program in my mind, but I'm fundamentally unable to track my own location in space. If I walk through a building and take two quarter turns, my ability to reason about where I came from and what's what direction folds over itself in on itself like the collapse of that 4D hypercube house in the Heinlein short story.
The connection to tracking beats was already apparent to me from experience: although I enjoy music, I subjectively experience lengthening and shortening in the time signature even on the scale of between beats in an 8 count. I actually had not understood that music had a beat until I went to a Zumba class for a few weeks and said, "OK I have just one question: how does everyone know WHEN to move?" I had to have someone tap my shoulder on every beat, and the multi-sensory experience like that allowed me to understand what the beat in music was and it was like not knowing there was another sense. (Prior to that I had assumed "the beat" meant "every percussion no matter how rapid" and couldn't figure out how people picked certain ones.
Interestingly, through years of various dance practice since then, I have now got to the point where I can keep a beat, most of the time. But, I still don't "hear" the beat. Instead, I experience it as like that half-breath-taking jolt of acceleration you get stepping onto a moving walkway or if you can imagine grabbing a door on an open train. When I catch the beat I feel it that way, and if I get off beat while dancing and need to catch the 1 or 5 I have to stop for a second with an imaginary hand out to catch that train car and be pulled along again.
While learning dance I felt like there was a varying random time delay between my different senses of hearing the music, seeing people move, moving myself, and my own kinestetic sense that I had moved (I have trouble with sensory fusion in general). It was frustrating to the point of literal tears because I wanted to do it but I couldn't get the circuits in my brain "forward the packets through the network" with a non-random latency. However over time it improved & I think it probably improved my other perceptual issues.
> Sometimes when I close my eyes I experience a sense being an ant in a tiny room versus being the size of Galactus in a solar system sized room, and then warping back and forth like looking backwards through a telescope. That is, the relative scaled distances remain the same but the subjective sense of absolute scale starts to oscillate.
I have long had a feeling like this, like being tiny by simultaneously huge, but never have heard of anyone else who had experienced it, probably for lack of a good description of the phenomenon. Great description.
I've experienced something similar! But for me, it only happens when I'm sick. I can at times almost use it as a precursor that I'm about to be sick. I think it might be called "Alice in Wonderland syndrome".
Changes in spatial perception might also explain some mental visions, like truly massive scale structures that are hard to imagine when sober, but those incidents aren't as profound on acid in my experience, and you don't see them visually. They're more high-definition thoughts.