What is normal?

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Let me just say that this post was first made on a recreational drug forum, and that no one replied. Perhaps most drug users are drooling idiots?
In any case, I have NO IDEA where to put this post, so there is a good chance this doesn't belong here. However, I would imagine more insightful/intelligent people linger around here and might be able to answer my question with some substance and detail. If you know of a better place to put this question, please let me know.
The question deals with perception. It really doesn't fall under psychiatry, but it is indeed a mental question and I can't even begin to think of a more appropriate place to put this question. Here was the original post -


Someone I don’t know (his name is ME) used Ayahuasca not too long ago (for recreational reasons). I'm not sure if everyone is familiar with it, but it's a pretty neat little psychedelic that requires you to make it (not available on the streets).
But forget all that. I'm more interested in specific biological properties and the changes that come when psychedelics and the like are taken.

While on Ayahuasca, one thing ME found insanely interesting was my hearing.
I am a musician and write and record music regularly. The music I compose I suppose harks back to the 1970's - heavily arranged.. etc. While on Ayahuasca, ME put on my most recent demo to show my friends, and while in the dark, they had a great mind feast with what I imagine to be vivid lucid visions. While I had those nice lucid visions as well, the thing that most interested me was my perception of pitch. The first song on the demo clocks in at around 15 minutes, and I spent a great deal of time recording it, so my mind's "ear" is quite familiar with the proper pitch and tempo.

But a funny thing happened. While playing the demo under the influence, I heard a DIFFERENT pitch and tempo!

The song kept speeding up, and slowing down. Weirdest of all - the pitch kept changing. What was "normally" a C actually sounded like a D#, yet this relation wasn't quite that consistent. Where a C note would normally have been also sounded like a C sharp, or even lower like a B.

My first question to myself was, "then, how do I know what a normal pitch is?". What is "normal" ??

What specifically did the ayahuasca do to ME's hearing, that caused him to hear "improper" pitches?

Let's use a fly as an example. I've learned that a fly usually outruns us because when you swat at it, it's brain processes vision at a much slower rate. The fly sees my hand moving slower than it actually is...but what is "actually"? To the fly, it's vision rate is "normal" because that's just how it is.
To me, my speed of vision is "normal" because that's how it is. To me, when a play a C chord on my piano, it's normal because that's the rate of my hearing perception.

But what about being under the influence of Ayahuasca? When ME plays a C chord on my piano under the influence of ayahuasca, it doesn't sound like a "C". It sounds like a different note. It can sound like a D, or a B flat. So my real question is, what exactly in my brain decides what a "normal" auditory perception is? And when that perception is altered by ayahuasca, what part inside of my auditory receptors is it changing to make me hear different pitches than what is otherwise "normal"?

I'm really looking for an answer, because I just have to know about these things. I've read about "rate theory" and how our perception of sound/pitch is determined by the rate of auditory neurons firing, but that's about all I've been able to find. This little vague description doesn't move me. Can anyone add anything, or help me answer my question? Has anyone else ever wondered this? I would really like to get a more scientific discussion started, rather than a spiritual "far out" thing. ME was coherent enough on ayahuasca to play a C chord on his piano and wonder "why the hell is the pitch changing!"



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Although I am not an MD, I just had to pipe in. Ayahuasca, when prepared properly is an hallucinogenic. Much like LSD, it alters your visual, auditory, and physical senses. This alone would explain why you (ME) hears music and notes differently. It also has tendencies to cause paranoia and/or anxiety. Although the way you feel while under the influence may seem inspiring, creative, or enlightened, you have to understand that it is altering the normal chemical balance in your brain causing you to feel this state of euphoria. Also, the more you use Ayahuasca, the more you need to feel the initial rush or euphoria. With any hallucinogenic, there are adverse effects which may last far after you have stopped using the drug. I would be very concerned about the long term effects considering you are playing with your brain, and your brain does not regenerate new neurons once you have damaged them. My advice would be, if you like to make music and want to continue, stop the psychedelics! Some more food for thought, you seemed to be fascinated with perception and how you know what is really your real perception. Check out Rene` Descartes, he is a famous philosopher whom, although not under the influence of hallucinogens, ponders what is really real and what is thought and taught to be real.


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The central question of the post is an old one to neurosciece. However, usually it takes a slightly different form. The way it most comonly posed is: "How do I know that my red is the same as your red?" This of course refers to whether or not two people perceive colors in the same way. Extending it to audition isn't an enourmous stretch.

The general answer is you can't really tell, or at least as far as I know. But, the next question would be, does it matter? I would say probably not. Regardless of whether my blue is your blue or your red, we would both agree that the color of the thing out in the world is the same. Now, you might wonder then, if there is a diference, and we each perceive diferently, then if you write a song will others who hear it the same as you like it better than others who hear it diferently?

As for theories on audition, you can look into volley theory vs. rate theory. Rate theory can't accound for all of the amazing things the human ear can do. Especially when you learn about the physical limitations of neurons. For example, they can't fire at a rate of 5,000 times per second, how would they do with a 5,000Hz tone? You might be interested in a read of Quest for Conciousness: A Neurobiological Approach, by Christof koch.

An equally troubling question would be, why are you writing 15min long 70's rock songs?