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How is vision enhanced by psychedelics?

ebola! said:
>>Wow, nobody mentioned the treatment of glaucoma with marijuana. I'm pretty certain that this changes the pressure in the eye which allows better vision. It doesn't work through changing how dilated the eye is. That shouldn't effect anything really except the amount of light in your eye.
>>

This is a function of marijuana's vasodialatory effects in the eye rather than any psychedelic action.

ebola
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ebola you are very knowledgeable. thanks for the info.
 
Hey FB, do you know if there is a source to the info you gave above. I'd very much like to see anything that talks about that. Sounds very neat.

peace,
S_S
 
fastandbulbous said:
The way psychedelics act on the V1 part of the visual cortex is to effectively lower the threshold for a neurone to fire, but this is also related to whether an adjacent neurone has/is firing (inhibits adjacent firing, increases firing if more distant neurones. Put those criteria into a computer to simulate increased firing/inhibition of neurones & you get geometric shapes forming. Now add in the info being fed into the V1 area (from the eye) as well as random firing of individual neurones & voila, you CEV animated trip patterning.

Now considering the structure of just about everything in nature can generally be traced back to very simple mathamatical algorhythms (fractal spiral of shell, hexagonal pattern of honeycombs etc), you're just increasing the overall ability of the V1 to generate those common shapes, which when fed to the part of the brain responsible for pattern recognition & interpretation makes vision seem more acute. This will, in a certain percentage of instances result in misidentification, but you'd never realize it was an incorrect interpretation unless you get close up to it to compare (& in all honesty, how many times have you done that while under the influence?)

Overall, the effect of psychedelics is probably something akin to how photomultipliers (in night vision goggles etc) work. Sometimes multiplying up the odd stray photon means that you end up seeinmg something that isn't there (but in incredible detail!)
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F&B, Would you agree that this doesn't neccesarily mean that the internal representations correlate less accurately with the external?
 
fastandbulbous said:
The way psychedelics act on the V1 part of the visual cortex is to effectively lower the threshold for a neurone to fire, but this is also related to whether an adjacent neurone has/is firing (inhibits adjacent firing, increases firing if more distant neurones. Put those criteria into a computer to simulate increased firing/inhibition of neurones & you get geometric shapes forming. Now add in the info being fed into the V1 area (from the eye) as well as random firing of individual neurones & voila, you CEV animated trip patterning.

Now considering the structure of just about everything in nature can generally be traced back to very simple mathamatical algorhythms (fractal spiral of shell, hexagonal pattern of honeycombs etc), you're just increasing the overall ability of the V1 to generate those common shapes, which when fed to the part of the brain responsible for pattern recognition & interpretation makes vision seem more acute. This will, in a certain percentage of instances result in misidentification, but you'd never realize it was an incorrect interpretation unless you get close up to it to compare (& in all honesty, how many times have you done that while under the influence?)
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So... Serotonin causes the brain to interpret stimuli that aren't there. The brain compromises by interpreting them as common form it has evolved to perceive.

What I don't understand is why visual acuity will be enhanced despite pupil dilation. One would expect the exact opposite no matter how much stimulation the psychoactive offers.

I have always understood form to ascribed directly after the information is passed through the cones. This would be way before any neural process would lend its hand into the interpretation of the experience, therefore serotonin shouldn't factor into it...

I really would like to believe that all this extra stimuli really is there. Maybe we evolved without the capabilities to perceive it because of its complete irrelevance to our existence. It really doesn't add up though, its just wishful, biased thinking.

Also, does anyone have any idea why psychedelics create an inclination of nature and spirituality?
 
BurnOneDown said:
So... Serotonin causes the brain to interpret stimuli that aren't there. The brain compromises by interpreting them as common form it has evolved to perceive.

I really would like to believe that all this extra stimuli really is there. Maybe we evolved without the capabilities to perceive it because of its complete irrelevance to our existence. It really doesn't add up though, its just wishful, biased thinking.
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I'm not F&B but the way I understand it is.
Reducing the threshold required for neurons to signal results in more internal stimulation. The internal representations/neural correlates/firing patterns of external stimuli could be described as exagerated.

I don't think it's all just wishful thinking.
There is no reason why your internal reality has to be any less accurate while on psychedelics.

and From an evolutionary stanpoint the effects of psychedelics don't really help an individual survive and reproduce.
 
and From an evolutionary stanpoint the effects of psychedelics don't really help an individual survive and reproduce.
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I'm sorry, but psychedelics have absolutely nothing to do with evolution. We didn't involve any close symbiotic relationship, or a parasitic one, and I can't think of any other other sort of evolutionary relationship that would make sense there.

It's like saying that "from an evolutionary standpoint" corn does help us survive and reproduce.
 
Ham-milton said:
I'm sorry, but psychedelics have absolutely nothing to do with evolution. We didn't involve any close symbiotic relationship, or a parasitic one, and I can't think of any other other sort of evolutionary relationship that would make sense there.

It's like saying that "from an evolutionary standpoint" corn does help us survive and reproduce.
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I was just reiterating that from an evolutionary standpoint psychedelics appear to be irrelevant to our existance.
I thought everything had something to do with evolution. eh?
Why can't you look at the human- psychedelic relationship from an evolutionary standpoint?

Whats wrong with saying that from an evolutionary standpoint corn helps us survive and reproduce?
 
Aye... anyway...

The paper was a one BilZ0r originally posted about a computer model of the V1 nerve structure, when given a 'virtual trip of LSD' (lowered thrsholds for firing & interactions with adjecent neurones as described) produced very accurate CEV tpes of patterning and when fed 'sensory' info from a camera, did a lot of what psychedelics do to visual perception. You'd have to trawl BilZ0rr's posts to find it, but with a search it shouldn't be too difficult (too lazy to do it myself!). Very interesting read - he used to find some interesting little gems, he did :D
 
http://www.archive.org/details/redwood_center_2006_02_14_cowan

Jack Cowan: Spontaneous pattern formation in large scale brain activity: what visual migraines and hallucinations tell us about the brain (2006)
Redwood Center for Theoretical Neuroscience

... this one? Even if it's not, it's a cool lecture along these lines. Those Lye geometries pop up in lots of interesting places, heh heh.
 
uncomfortablepants said:
I was just reiterating that from an evolutionary standpoint psychedelics appear to be irrelevant to our existance.
I thought everything had something to do with evolution. eh?
Why can't you look at the human- psychedelic relationship from an evolutionary standpoint?

Whats wrong with saying that from an evolutionary standpoint corn helps us survive and reproduce?
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Well because corn had no impact on our evolution. It wasn't even known (for us of european descent) until quite recently, certainly not long enough for it to have had an impact on our evolutions.

The same is mostly true of psychedelics.

Outside events have nothing to do with evolution. Today I went to work, but that doesn't mean I evolved to work. Evolution is a biological thing, not something based upon life experiences as many people like to think.
 
Ham-milton said:
I'm sorry, but psychedelics have absolutely nothing to do with evolution. We didn't involve any close symbiotic relationship, or a parasitic one, and I can't think of any other other sort of evolutionary relationship that would make sense there.

It's like saying that "from an evolutionary standpoint" corn does help us survive and reproduce.
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No, no... uncomfortablepants misinterpreted my post, and you misinterpreted his post. I will try to clarify.

I hope those perceived stimuli really do exist (as perceived extensions of reality instead of hallucinations fabricated by the brain), I find it unlikely. Although, the fact that these hallucinations are completely irrelevant to our existence gives me reason to believe we may have evolved without the ability to perceive them even if they are part of reality. But I know that is just wishful thinking.
 
Yeah nah i'm not convinved psychedelics had an evolutionary role eh.

It's unsurprising that compounds which resemble our own neurotransmitters pop up elsewhere in nature, due to shared synthesis pathways in organisms which then undergo mutation, etc. It's also unsurprising that these variant compounds cause disturbances to the delicate neurochemistry that dictates our concious experience.
The fact that they have certain mental effects doesn't have any appreciable effect on evolution because the timescale is too small.

That's not to say they're worthless though, at all.

(large glasses of carrot juice? shudder. horrible stuff. that vinto stuff looks kinda yummy though.)
 
If psychedelics make neurons stay firing for longer (which would explain trails,) maybe this would cause more to be percieved at once. That is, if one little peice of the visual field were normally described with two cones that fired alternatingly, and a psychedelic caused them to keep firing, twice as much information could be sent. Right?
 
Ham-milton said:
Well because corn had no impact on our evolution. It wasn't even known (for us of european descent) until quite recently, certainly not long enough for it to have had an impact on our evolutions.

The same is mostly true of psychedelics.

Outside events have nothing to do with evolution. Today I went to work, but that doesn't mean I evolved to work. Evolution is a biological thing, not something based upon life experiences as many people like to think.
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I thought evolution was a continuous proccess?
Maybe I should have said adaptation due to the relatively short time scale.
If corn wasn't known about until recently, how many generations does it take for evolution to occur?

There are no outside events and you adapted to do your job.
When you get down to it learning and evolution are very similar things.
Who said evolution is a biological thing? The word is very applicable to other areas.





and I don't see any reason why the effects of psychedelic drugs are inherently delusional or lead to innaccurate internal representions of external stimuli.
 
Evolution is a biological thing in this context. The conversation was about humans and psychedelic plants evolving together. What other sort of evolution is applicable?

Evolution occurs every generation. Some changes are bad, and some turn out good. They're all entirely random though- if some random mutation is good, it'll be kept. If it's bad, the poor critter will perform poorly, not pass it's genes on and it'll disapear.

Things don't evolve for a reason. They evolve entirely by chance. That's why it takes so long. If every generation had the most appropriate mutations occuring, it'd happen very rapidly. That's just not the case, though.

Learning and evolution are not remotely similar. Learning occurs within a brain, within a liftetime. It can be passed down, but it has to be re-learned every time. Having it in a book instead of having to directly figure things out just makes it a hell of a lot easier.

Evolution is purely biological.

If corn wasn't known about until recently, how many generations does it take for evolution to occur?
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Tens of thousands? Corn didn't evolve along with humans. It was almost exactly how it is today, just bigger (through human conducted selective 'breeding' efforts). Again, corn didn't evolve "because"- it happen by random chance, and it turned out that this worked well for it, so the ones that are the way it is, were kept, and others faded out. It turned out that animals ate it and passed the grains on, or if not, the seeds could still make it to the ground and grow again. This was long before humans.

Maybe I should have said adaptation due to the relatively short time scale.
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No, you shouldn't have. Adaptation is the same thing as evolution in this context. You can apply whatever mystical overtones you want, but there's only one thing guiding the changes in a species from one generation to the next: the ability for those changes to improve the likelihood that it'll live and reproduce. Neutral changes will likely fade out over time, or continue on as a subspecies or perhaps a new species if the change was large enough, but they other species would still remain, since they have equal chances of passing on.

Having psychedelic drugs within a plant seems to be a bit of a neutral change- or an abberation in the biosynthetic proccesses. It doesn't seem to give any benefit to the plant to live onto the next generation, though some DMT containing grasses live on better because once a sheep eats some, it'll never eat it again.
 
Evolution is a very economocal thing. If the plant puts that much energy into making allkaloids, it would have become extinct if it didn't confer an advantage of some sort as that would effectively be wasted energy. Can't think of a case where that doesn't apply
 
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