[IIAOPSW]

So I'd agree you generally won't get perceptions constructed seemingly out of whole cloth. They are more like non-optical illusions. Similar to optical illusions in the sense of being a form of erroneous perception which you are aware is erroneous but not really fooled by. Non-optical in the obvious sense that the mechanism isn't the same as a normal sober state optical illusion. Let's call them "distortions" instead and not get stuck on vocabulary.

There's a few reliable ways to manifest distortions and to notice the amount of distortion in your present state.

1. After images. Stare at a bright spot such as a lightbulb or a beam of sunlight through a crack for several seconds. Then close your eyes. The normal after image you are used to should now take on a deeply geometric shape rather than smoothly diffusing away.

2. Look at TV static / towel / white noise texture. These patterns are extremely reliable at manifesting crystals and fractals. I have theories why, but lets stay on point.

3. The dead man switch. Set a timer for 20 min. When it goes off, verbally acknowledge and reset. This isn't visual, but the first and most subtle distortion is your sense of time and this will make you acutely aware of it.

4. Thin line on white page. It should reliably start to jiggle around as if it were a wave on a string.

As a general rule, things which have very fine grain spatial components will be distorted in some way. If you must know the theory for whats happening (which I can back with scientific citations), the brain is doing something similar to the way jpeg/mp3 compression works. Namely it converts the incoming information into frequencies via a fourier transform (in some weird, highly optimized basis) because information processing is generally easier there. LSD changes the reference clocks so everything is out of phase. Every frequency is being slowly phase shifted from where it should be, which then causes it all to move as if it were following a wave equation.

[Errancer]

So if this is what we would consider "hallucinations" then sure I experienced all this and more. One of the more interesting experiences for me is when I try to cook food on acid. On day to day basis I am quite good cook and I can reliably judge how well done something is but on LSD all those abilities simply disappear. I can't tell if the meat on the pan is done or not without thermometer. But I think reducing hallucinations to distortions doesn't fully capture what is going on. LSD affects the mechanism of active perception as well as the passive perception. I think when we talk of hallucination then this is the area people have in mind and what is important hallucination is one of the least interesting ways acid affect active perception. What I mean by active perception as contrasted with passive one is that all things you mentioned are passive perceptions. But our mind does not only recognises objects in the world but it is also participating in constructing new categories which establish new objects. For further reference the key-word is "The myth of the given" but what I want to point here is that this ability of the mind to put sense data under categories is affected with LSD in a incredibly interesting way. This is why hallucinations as perception of things which completely don't exist are so difficult to have and you either need to have a "special type of soul" or take such a large dose that you no longer operate on external sense data since they are so distorted.

[IIAOPSW]

You're trying to clarify the neat categories you'd like to draw between layers of abstraction. As if to say "oh absolutely it effects the raw input (active perception), and maybe a tiny bit of that subconscious processing one step above there (passive perception), but I've never had it leak all the way up the chain to the seat of consciousness itself (hallucination)". Which is fine I suppose though I don't see what this structure adds.

You're correct that my immediate tests are all at the lowest level of abstraction. I picked them simply because they are the types of distortions which manifest first and quickest and least ambiguously. If you or anyone else isn't sure if the acid has kicked in, or is uncertain that they are experiencing any changes, these are the debugging tools. At higher levels of abstraction you get things like streamers, transposing of near identical objects, and sometimes even weird face distortions.

The taste thing is quite curious to me. Have you considered setting up an experiment to try and pin down exactly which flavors are distorted and how?

[Errancer]

If we are looking for tests whenever we are tripping or not then sure, what you described is definitely the way to go. The categories I am drawing are not important for that. I make them to on the one hand tell people that they probably won't lose their consciousness and on the other that there will happen something more than simple "eye-filter". This middle step I find the most interesting, possibly dangerous and missing from wide-culture discussion so I want to pin it down. Especially that it is interesting feature of the mind independently of psychedelics. An experiment with tastes could be interesting but lately I simply avoid eating while tripping since I feel my stomach too vividly. Once I had to eat plain rice for some time after the trip since everything else was too overwhelming.

[IIAOPSW]

It was probably in Psychedelic Information Theory where I read the closest to the missing middle you are looking for. The visual system, being the most complex, is the most fragile and thus any perturbation is likely to manifest as neat geometry first. Most commonly this takes the shape of one of the form constants, which is pretty easy to explain as those patterns are directly encoded in the first few layers just after the optical nerve. So you randomly poke any neuron there, you'll get those shapes. Even waking up tired can cause it (hypnogognia). The next layer of distortion up has to do with the main loop structure (hypothalmus loop? its been a while my memory sucks). These sorts of distortions you might miscategorize as the first kind since they are still most often just "vfx magic eye filter". But they aren't so simple and in fact are distortions of a higher order of pattern recognition. I'm talking about effects such as a moving object appearing to be multiple places as though a strobe light is flickering. Or looking for a dot and suddenly seeing dots amplify everywhere in your view. By that point coherent speech is a bit hard to manage and focus is usually not forthcoming for any multi-step task. From there its pretty much a continuum on up to the point where understanding the difference between in your head or not also becomes a noisy signal. But that usually doesn't happen on acid. I get what you're after, I think a continuum of effect is a more apt concept.

Without eating per se, would you consider testing an assortment of tastes such as salt, sugar, whatever spices you have etc?

[Maursault]

> Let's call them "distortions" instead and not get stuck on vocabulary.

Let's not. What you're describing are known as pseudo-hallucinations. i.e. The floor looks wavy and like it's moving, that sort of thing. A hallucination is seeing something (and is always visual) that isn't there, such as a person or object. Delusion is believing these are real and endorsing as real, but delusion often occurs without hallucination, such as believing someone is in the room without visually perceiving them. Delusion is somewhat related to fantasy, it all depends on whether it is believed to be real. Aural hallucinations are, of course, hearing things that aren't there.

[nanidin]

The term used by people that seek these things out appears to be “visual effects”[0] and it apparently includes any sort of change in visual perception. I have never come across the term pseudo-hallucination to describe these phenomena before this comment.

[0] https://psychonautwiki.org/wiki/Visual_effects

[Maursault]

> I have never come across the term pseudo-hallucination to describe these phenomena before this comment.

Must not exist then.[1]

[1] https://en.wikipedia.org/wiki/Pseudohallucination

[nanidin]

From the linked page: “The term is not widely used in the psychiatric and medical fields, as it is considered ambiguous.”

[IIAOPSW]

lmao he just pseudo-shot his own foot.

[mandarax8]

Any source on that theory or is it your own?

[IIAOPSW]

Arguably both, since I thought of it but later found I've been beaten to it at least twice. Steven Lehar beat me by 20 years and made a phd thesis out of it.

http://slehar.com/wwwRel/

Psychedelic Information Theory also echos basically everything I was conjecturing at the time and backs it up in a ton of depth.

http://psychedelic-information-theory.com/

To give a quick summary of what I'm talking about, the brain waves rather than the individual neurons are the representation of everything. Brain waves are a consequence of closed loop neuron paths and propagation delay. The longer the loop, the lower the frequency. One consequence of this is that complex signal processing tricks like fourier transform fall out very easily, far more easily than if you tried to train a regular neural net to do it. Now if you poke at the timings or connections at random, you are more likely to hit a long loop than a short loop. Hence, LSD distorts a very particular band of brain wave frequencies. You can make words just fine but sentences lose their way.

A paper that confirms the fourier trick is going on in the optical system: http://www.math.utah.edu/~bresslof/publications/01-3.pdf

Experimental evidence of the shift in frequency partition function due to LSD https://www.nature.com/articles/s41598-017-17546-0.