Pain, Pleasure and Neurobiology

[smalltalk]

What happens when I cut my finger?

A pain sensor will "feel" the tissue displacement and send an electric impuls through a nerve fiber, up my spine into the thalamus. There, the signal is distributed into various brain areas and causes certain activity patterns in my cortex. Then I will finaly "feel" the pain and cry out. I will localize the pain in my finger. But is it really the finger, that hurts?

How is it possible that mere electrical or chemical impulses from our body can be experienced as pleasure or pain? Why does one brain pattern translate to pain, while another translates to pleasure? A nerve signal only carries a harmless amount of current, it is not the signal in itself that hurts. Also note, that no one indivdual brain cell is actually hurting. Brain activity in itself cannot hurt. Could it?

Why don't we just recieve sensations as technically detatched as we regard the fuel-level meter in a car?

(Of course, I know it is very usefull the way it is. Wouldn't do me no good to run around with a broken leg. It is the pain that makes me stop do that. As pain will make me withdraw my hand from the fire very quickly. And babies would be quite less in numbers without the pleasure involved in making them.)

But there are more mysterious facts: You may all have heard stories about phantom pain, when people with an amputation say the toes on their missing leg were hurting. Otherwise I guess everybody has got a bruise sometime and only noticed long afterwards. Faquirs are said to be able to blend out pain at will. There are claims that hypnosis can be used as a pain blocking device.


I would assume that my sensations, feelings and even thoughts have a clear correlation to activation patterns in my brain cells or in neurotransmitter and hormone levels. Whatever it is called. I don't know about these things. But I guess, if I knew everything about the brain, from the wiring of the nerve fibers and neuron cells to the chemical processes involved, I still couldn't explain why this very arrangement "felt" good or why another one hurt.

Maybe this sounds like a theoretical question, of the same calibre as if to ask why red looks like red and not like green.

But there are a few - more or less practical - follow-up questions attached to the problem:

- If some little green men were to show up here, I'd bet they'd have sort of a pleasure-pain mechanism, however green and slimey their chemistry was.

- Assuming, there could be an intelligent machine, could there ever be any pleasure-pain cicuitry implementet? or the ability to see at least a shade of red.

- Does a worm feel pain? An insect?

- Perhaps the nerve signal from an injury is quite the same as the one from a delicate touch, only the channels are different. If I could induce some voltage into the right nerve vibers, I'd be experiencing utter pain or pure pleasure.

 

[Mojotronica]

Pleasure is muted pain, or perhaps pain is pleasure taken too far...

This thread is very Clive Barker, BTW...

 

[Aphex_Twin]

The point of view of a semi-initiated:

First part of smalltalk's post

It's true, we don't feel pain or pleasure on our skin but in our brain. One example would be of a young woman that had an accident and had her entire scalp cought between the gears of some machine. Whan the scalp was replanted, the nerve s in the skull wired randomly with the receptors in the scalp. This made that when the left side of the scalp was excited then the young woman would feel it in another side of her head. Of course, in time, she learned to use her new connections.

Also, colours are an abstract concept. We learn to distinguish between them, during our lifetime, but the connections to do so are random, and different in each individual. Yes, "green" can be "red" for someonelse. Most likely the concept of the colour "green" would corespond to a totally different concept .

Fachirs are the best examples to show that pain or pleasure lie in the brain. Theese people have managed to alter their brain connections so that pain can become insignificant.

- Assuming, there could be an intelligent machine, could there ever be any pleasure-pain cicuitry implementet? or the ability to see at least a shade of red.

Obvioustly, emotions are a very powerfull evolutionary tool. If we would ever trigger machine evolution then it is expected that a correspondent to emotions would rise.

- Does a worm feel pain? An insect?

A worm feels pain because it has a nervous network. However, that pain is received at a very low intensity and is rather a mechanical process.