ELI5: What do hallucinogens do to the brain that causes it to hallucinate? What causes fractals and auditory discrepancies?

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ELI5: What do hallucinogens do to the brain that causes it to hallucinate? What causes fractals and auditory discrepancies?

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  1. Bomdiggitydoo Avatar

    The brain gets unlocked and you’re seeing the code behind the simulation

  2. trotting_pony Avatar

    No idea, but if you have VS, then likely you see fractals regularly or even on demand when you close your eyes.

  3. rhetoricalnonsense Avatar

    Hallucinogens disrupt communication between different brain regions mostly by altering th affect of neurotransmitters. For example, LSD, psilocybin, affect serotonin transmission by binding to specific receptors which causes abnormal cellular signaling, resulting in effects we call the “trip”.

    Edit: As others noted, I poorly combined LSD and psilocybin suggesting they were the same. That was not my intent. Fixed.

  4. devenjames Avatar

    A simple answer could be that the brain has formed some fundamental archetypes for geometrical forms and mathematical relationships and when under the influence of hallucinations a filter of your thinking process is removed allowing you to observe the raw sensory experience of thinking that is normally hidden to your consciousness. But that’s based on nothing but my own speculation!

  5. nahhhh- Avatar

    Your brain is made up of lots of little cells called neurons. They talk to each other by sending out messengers (neurotransmitters) which talk to special message takers on other neurons (called receptors).

    Hallucinogens (alongside most other drugs) pretend to be messengers and trick the message takers into thinking there are heaps of messengers around. This makes the brain do strange things like see things which aren’t there, or think silly things.

  6. StealYour20Dollars Avatar

    My understanding is that it releases a bunch of feel good chemicals that have no assigned stimuli so your brain makes up stimuli to match. That ends up being what you hallucinate.

  7. CleanMios Avatar

    Maybe my own belief mixed in with some truth here:

    Science does not know except in concrete physical terms (receptors, neurotransmitters, agonists antagonists etc). Why consciousness is elevated in such a way has not been figured out. Consciousness and anything related to how it feels is subjective, anything objective about what consciousness is, is considered a “hard” problem in science. Aka unsolvable.

    An LSD or Psilocybin experience is truly a mystery and the only way to learn about it is to partake imo. It’s miraculous, be safe.

    DMT is even more vivid and surreal. You break through the walls of reality and discover other dimensions and entities and communicate with them. Some are angry, evil, and spiteful, others are good and can help guide you. Why this subjective experience is similar amongst all DMT users is truly confounding.

  8. liquidnebulazclone Avatar

    Classic psychedelics like LSD, psilocin (mushrooms), and mescaline (peyote) activate several types of serotonin receptor, with 5HT2a being the most relevant to hallucinogenic effects. Serotonin receptors affect many other systems in the body through signaling cascades. Activating a serotonin receptor can send multiple chemical signals that induce further signals and changes in neuron activation. It turns out that “how” the 5HTa receptor is activated matters in what signaling cascade follows.

    There are compounds that activate the same receptors as psychedelics without causing psychedelic effects. However, it is possible that altering the balance of different signaling cascades changes how the brain manages the flow of information. This seems to be supported by imaging studies that show increased overall signaling throughout the brain, appearing less orderly and more like that of a child.

    If I had to speculate about how hallucinations arise from this, I start with the fact that we know the actual images formed on our retinas are processed in the brain to make them user-friendly for consciousness. This means blind spots and blood vessels, and generally rendering it as a complete picture happens somewhere in the brain. We also use memory to fill in the image based on expectation and pattern matching, so this is how hallucinations can take on complex geometry and solid forms. I think the complex code governing our brains is mathematical on some level, so fractals emerge as a result of pattern matching.

    I know this is a very materialist explanation to something many people see as mystical. I think the fact that consciousness exists at all, or anything for that matter, is the mystical part, but our brains and everything else functuon mechanistically within the natural world.

  9. frank_mania Avatar

    The ELI-much-older-than-5 answer is we’re very very far short of knowing, frankly. We can only make educated guesses about how the chemicals interact with brain chemistry, some of them quite good. We have a pretty good idea of why MDMA makes us feel so good–but only because it causes our brains to create lot of serotonin, and prevents it reuptake. But we don’t know how or why serotonin makes us feel good in the first place–or feel anything.

    LSD and psilocyn and DMT are much more obscure, except for how similar they are in shape to serotonin. But simply saying that they mimic the neurotransmitter is probably falling very short of their action. We know that under their influence, a far larger area of our brain is highly active, using more oxygen than normal. This points to something far more profound than simply a mixed up system that’s confused by the presence of a near-match molecule. Add to that the fact that other substances with molecules very similar in shape/composition to serotonin and other neurotransmitters have no noticeable effects.

  10. asweatyboi Avatar

    Your brain uses Chemicals (neurotransmitters) to talk to different segments of itself to figure out what’s happening

    Hallucinogens usually either look like an already existing brain chemical and make things funky or they cause more brain chemicals to get made, making things weird

  11. BoysenberryFun4093 Avatar

    I took Lsd one time and….well I’ve taken it many times but one time in particular I spent like 5 hours wondering why I had this pain in my stomach. Turned out I had to pee 😁go figure. I then spent what seemed like an eternity pissing in the bushes. It had to have been at least 3 minutes long. Hahaha

  12. dorothy_sweet Avatar

    The most plausible hypothesis I’ve seen so far for the common visual effects is that since psychedelics cause unrestricted flow of glutamate which opens normally closed pathways in the brain, processed/corrected/already interpreted imagery which is normally on a one-way-street can loop back and then be processed again, and again, and again, each time trying to extract more detail, meaning, relevant concepts to human consciousness such as entities (like in recognising animals in dense foliage) or patterns (like in plant identification) end up amplified in the image until they are noticeable, which leads to a ‘flowing’, ‘melting’ or ‘shifting’ as the image data gradually drifts into something with more clearly defined concepts, similarly to how AI image generation iterates upon noise until it has ‘reconstructed’ something close to the concepts it has been pointed to in latent space (a mapping of concepts to probable imagery). This would explain why the effect is most intense when staring at a single spot and can often be reset by moving your eyes or head unless you get to a point where the effect is simply so intense that either the overprocessing of the noise present in your vision already overwhelms everything else, or nonvisual parts of your brain activity leak into the visual processing loop and overwhelm external imagery (as is sometimes seen in hallucinatory geometry in LSD representing memory structure or in psilocybin representing parallel processes in the brain.)

  13. Zotoaster Avatar

    They shut down the filter between the conscious and unconscious parts of the brain, making you aware of what’s usually happening inside

  14. LiquidInsight Avatar

    Regarding the observation of fractals, waves, and spirals, there’s some (1) work (2) that suggests that these reflect spiral waves in the visual cortex. Spiral waves are a universal phenomenon that appear in excitable media (a common example is the BZ reaction), which is a good first order approximation to neocortex. I’m not certain that experimental work showing the emergence of spiral waves actually used classical hallucinogens however — they may have used other pharmacological interventions.

  15. Ginden Avatar

    I assume that you use “hallucinogens” to refer to psychedelics like LSD or psilocybin. There are at least 4 chemical pathways that lead to hallucinations (5HT2A agonism of psychodelics, kappa opioid receptor agonism of salvia, NMDA antagonism, acetylcholine antagonism), with psychodelics being the most pleasant and popular drugs in this effect class.

    > What causes fractals

    This one was actually solved by math, and it’s caused by physical arrangement of neurons in your visual cortex – neurons are arranged in such way that symmetry breaking caused by malfunction of 5HT2A receptor results in seeing self-similar patterns.

    https://pubmed.ncbi.nlm.nih.gov/11860679/

    https://pubmed.ncbi.nlm.nih.gov/11316482/

    https://sites.pitt.edu/~phase/bard/pubs/Ermentrout-Cowan79b.pdf

  16. OneCow9890 Avatar

    Kinda irrelevant….
    I have epilepsy when I take magic mushrooms i go on a bloody trip!!
    I DONT recommend – i just take a handful of medications twice a day and I can’t imagine what goes on up there with the magic mushrooms and my medication interactions.

  17. lurkerer Avatar

    This is the best article you’ll find on brain function and psychedelics imo.

    TL;DR Your brain’s neural patterns or beliefs can be represented as a map with valleys representing those beliefs. The deeper the valley, the deeper the belief, like object permanence. Psychedelics are like if someone took the edges of that map and pulled outwards, flattening them to some degree. So you’re less likely to roll down into a valley and re-tread the same ground, you’re more open to different beliefs and assocations. Not necessarily correct ones by any means, but very interesting nonetheless.

  18. Mavian23 Avatar

    Everything you have ever experienced has been created by your brain. Imagine you are looking at a chair. Light comes off the chair and goes into your eyes. That light hits your retina and creates a signal that is sent to your brain. Your brain then uses that signal to create an image of a chair for you to see. You don’t see the chair, you see an image of the chair that your brain made for you. This is how all experience works. When you’re sober, your brain tries to create an image of the chair that accurately reflects the actual chair. But when you ingest psychedelics, the rules change. Your brain no longer prioritizes accuracy. It can create all manner of wild images of the chair, or even something else entirely. Nobody really knows exactly why certain substances have this effect. We know to some degree how they interact with the brain’s receptors, but we don’t really know why they change the way your brain creates experiences for you. That’s the gist though, your brain is an experience creating machine, and psychedelics change the way your brain creates your experiences.