
A Mathematical Theory for Why People Hallucinate - duman
https://www.quantamagazine.org/a-math-theory-for-why-people-hallucinate-20180730/
======
MisterTea
I've held this theory on my own after experiencing geometric shapes while
hallucinating after smoking a lot of marijuana years back. I sat down closed
my eyes and experienced an intense feeling of flying through what I can only
explain as the starfield screen saver from Windows but with colored 2D shapes
heavily dominated by hexagons of various sizes. During that experience I
realized that I might be experiencing the inner workings of my brain in real
time. I didn't give it much more thought but that ideas stuck in my mind for
years. Recently I began fitness training with a trainer who believes in the
stoned ape theory which reminded me of my own experience and I again read into
it a bit. I'm not sold on the idea but the overall theory is solid in my book.
Still to this day if I get really high I experience geometric hallucinations.

~~~
n4r9
I've mentioned this before on HN, but I don't understand why SAH is seen as a
"solid" theory. Psychedelics might increase some cognitive or perceptual
faculties, but McKenna never gives any physical mechanics for how this could
possibly lead to genetic alteration, i.e. how it creates any selection
pressure for intelligence.

~~~
__blockcipher__
As someone who bas taken a bunch of LSD, psilocybin mushrooms, and DMT, as
well as listened to a bunch of Terrence McKenna...the stoned ape theory is
total horse shit. It’s a slap in the face to evolutionary biology and just a
completely nonsensical “theory”

~~~
MisterTea
Not the stoned ape theory. I don't believe that at all. But the overall theory
of geometric shapes and the relationship with the interworkings of our brain.

~~~
n4r9
Sorry, I misread your comment. My bad.

~~~
MisterTea
Yea, that was a crappy sentence to begin with.

------
sonnyblarney
Is this 'hallucination' though? Or just some weird stuff happening in visual
processing?

I underwent some very serious periods of sleep deprivation (Army) and our
'hallucinations' were of a totally different kind: having conversations with
people that were not there, seeing things that were not there, misidentifying
people whom you know really well who are right on front of your face, taking
on different personalities etc..

~~~
lightbyte
That sounds like deliriant hallucinations as opposed to psychedelic
hallucinations. Deliriant drugs (such as Nutmeg, DPH, Datura, etc.) produce a
completely different hallucination experience compared to psychedelics. Often
times after taking these people do not even realize they are hallucinating
everything that is happening (conversations, other people, going places) until
they suddenly realize they have been simply walking around their bedroom for
hours. I imagine these work in completely different ways on your brain.

~~~
sonnyblarney
Good point - definitely the 'lack of self awareness' is a big differentiator -
that said, sensory and cognitive ability is seriously impaired to begin with
in these scenarios of sleep deprivation/stress induction.

It's also very scary once you do realize that you've been having a
conversation with 'nobody' (or a 'ghost' is what one might think) for quite
some time - it adds quite a degree of neuroticism.

On a funny/scary note - the weirdest of all is seeing two people apparently
'having a conversation' ... but upon closer inspection you find they are just
taking turns talking near gibberish at one another. All of the manner, body
language and tone of a 'conversation' but really, it's just two temporarily
crazy people mumbling ... with automatic weapons. Thankfully with no live
rounds in most situations :)

------
visarga
If you look at how neural nets work, they too tend to hallucinate. It doesn't
seem so mysterious to me. We have GANs, autoencoders and network visualisation
tools (finding the input that maximises a certain neuron or set of neurons) -
and they show that noise injection into the net can cause hallucinations.

------
everdev
> The sparseness of connections between inhibitory neurons prevents inhibitory
> signals from traveling long distances, disrupting the stochastic Turing
> mechanism and the perception of funnels, cobwebs, spirals and so forth. The
> dominant patterns that spread through the network will be based on external
> stimuli — a very good thing for survival, since you want to be able to spot
> a snake and not be distracted by a pretty spiral shape.

I see spirals every time I meditate. I find it interesting the suggestion that
meditation allows more random noise into my neurons.

It feels very similar to the dream state where the content usually has clear
connections to my real life but is randomized just enough to produce some odd
effects.

In the end, understanding dreams or hallucinations feels like interpreting art
to me.

------
Terr_
This reminds me of a short-story called "Blit", involving hacks against the
human visual system.

[http://www.infinityplus.co.uk/stories/blit.htm](http://www.infinityplus.co.uk/stories/blit.htm)

------
GuB-42
I wonder if the same effect can be reproduced with image recognition software.

The "Google deep dream" look very... acidic to me, but there were deliberately
induced by reinforcing a particular signal. But I wouldn't be surprised to get
similar effects by adding noise to the proper type of neural network.

------
liberte82
How do we know that reality itself isn't a mass hallucination?

~~~
JackFr
Because it's shared. Assuming you accept the existence of other minds, what
makes reality real, is that it's shared. Schizophrenic hallucinations are no
less real to the sufferer than so-called normal experiences. What makes
reality real is that every shares the experience.

That raises interesting questions about what is real and what is not, but also
questions about how much of reality is really the residue of culture and
worldview.

~~~
empath75
But people have wildly differing interpretations of reality.

~~~
fossuser
That's where science and experimentation comes in to some extent - individuals
should be able to reproduce results of someone else and see the behavior of
reality for themselves.

------
genericacct
Very interesting article. Some of the patterns it talks about are also usually
visible in the output of many deepdream / style transfer software that are
based on existing neural nets, which leads me to believe that they are indeed
mimicking existing brain processes.

(TBH this should probably be titled HOW people hallucinate)

------
mirimir
It's an interesting article. But I hate the header image. It's cool and all,
but has nothing to do with psychedelic hallucinations. And while Klüver's
"form constants" are OK, what's interesting about hallucinations isn't just
the basic geometry.

Consider LSD hallucinations, for example. I recall especially complex
entangled "ropes". Brightly colored, and in constant motion. Both spinning on
axis, and writhing. But the motions weren't just three dimensional. There was
a sense of stuff rotating and moving through other dimensions.

Also, the "ropes" had lots of detail. Almost like strings of characters. A
little like that G/E/B block on the cover of Hofstadter's _GEB_. I also recall
this guy who argued that all Hebrew letters were two dimensional projections
of some multidimensional object. He released a video, which reminded me of LSD
hallucinations. Very Kabalistic. And perhaps one inspiration for Aronofsky's
"Pi".

------
mailslot
If you stay partially aware as you fall asleep, you’ll see a ton of geometric
hallucinations. It’s just the way things work.

~~~
sleepybrett
The scientists in the article are trying to get to a 'why'.

