Meat Machine

If it's any help, here's a post I made in another forum for a chap who was arguing that consciousness is somehow seperate from the physical brain.


"OK, neurons 101. The 'electrochemical energy' is produced by ions and their movement.
When a neuron isn't sending a signal, it has a potential difference (voltage) of about -70 mV lower than its outside surface. This is called the resting potential. This is because proteins in the cell's membrane allow a net movement of positive sodium ions out of the cell (positive potassium ions move in, but I'll not go into that). When the neuron detects an impulse at its recieving synapse (more on synapses in a minute) other proteins - sodium channels, they're called - in the cell membrane open, allowing the sodium ions to move in. Once inside the cell, they diffuse out around where they came in, increasing the potential difference in that area, which causes more sodium channels in these other areas to open and allow sodium ions in. The inside of the cell becomes more positively-charged than the outside. This is called depolarisation.

When part of the inside of the cell has become sufficiently positively-charged, the sodium channels close again and the first protein I mentioned starts moving the sodium ions out again. The inside of the cell becomes more negatively-charged than the outside again. This is called repolarisation. Repolarisation will make the cell a bit more negatively-charged than the resting potential, so that the sodium channels cannot open again until all of the sodium ions inside the cell have been pumped out. Once the sodium ions have moved out the cell is restored to its resting potential and the sodium channels are free to open again. This mechanism prevents a nerve impulse going the wrong way, and ensures that nerve impulses remain distinct from each other.

But enough of that. A synapse is a junction between two neurons, through which a depolarisation may be transmitted. There is a tiny gap between the two neurons. In the pre-synaptic neuron are a bunch of little sacs containing proteins called neurotransmitters (which neurotransmitter depends on what part of the nervous system the neuron is part of). When a depolarisation reaches these sacs, they move to the surface of the neuron and release the neurotransmitter molecules inro the synapse. The neurotransmitter molecules diffuse across the synaptic gap to the post-synaptic neuron, where they are detected by protein receptors. Part of the structure of these receptors is of a shape that allows the neurotransmitter molecule to fit inside it. When a neurotransmitter molecule attaches itself to that part of a receptor, the receptor causes the sodium channels in th post-synaptic neuron to open, and hence a depolarisation to occur.

So. How would the ions (or neurotransmitters for that matter) being dispersed into the environment allow for consciousness to survive after death? And where is there any need in all of that for an independent, non-physical consciousness?

Edit: what consciousness is doesn't matter here, as you said that it's seperate from the body and I'm saying it's not."

Here's the thread.

[a different tim]

You'd have liked scathach's "illusion of consciousness" thread, which I think got regrettably eaten by the evil thread eating server monster. She's a pretty hardcore materialist neuroscientist. Ask her about dendrites sometime.....

There's some stuff on the "wonder bone" thread starting about post 109 (actually carrying on from an earlier conversation about sound illusions) which is relevant, especially scat's post on the Libet experiments, and some other stuff scattered about the threads as well. Then we all went off and read Ramchandram on neuropsychology. No-one in neuroscience, as far as I can tell, thinks consciousness is separate from the body, you'll be pleased to hear, not even the ones who are a bit religious on the side.

Steve Reich! Don't forget!

[Rhinoqulous]

a different tim wrote

Steve Reich! Don't forget!

Steve Reich is the bomb! My favorite is Music For 18 Musicians.

[Tenspace]

whoneedscience wrote

this?

Yep.

[Tenspace]

whoneedscience wrote

this?

Yep.

a different tim wrote

No-one in neuroscience, as far as I can tell, thinks consciousness is separate from the body, you'll be pleased to hear, not even the ones who are a bit religious on the side.

Yeah, that's what has me so confused. This guy is very intelligent, and he works in a related field. I'm just wondering if there's some part of the human brain that is beyond the capacity of any other method to replicate. For instance, I remember reading an article a couple years ago where people discovered that glial cells actually played a role in processing information, and they seemed to be completely shocked that they'd missed it for so long. Alas, I don't know anything more about it, and sciam, my other-field lifeblood, is a license nazi (I believe the article was something like "the other half of the brain").

a different tim wrote

No-one in neuroscience, as far as I can tell, thinks consciousness is separate from the body, you'll be pleased to hear, not even the ones who are a bit religious on the side.

Yeah, that's what has me so confused. This guy is very intelligent, and he works in a related field. I'm just wondering if there's some part of the human brain that is beyond the capacity of any other method to replicate. For instance, I remember reading an article a couple years ago where people discovered that glial cells actually played a role in processing information, and they seemed to be completely shocked that they'd missed it for so long. Alas, I don't know anything more about it, and sciam, my other-field lifeblood, is a license nazi (I believe the article was something like "the other half of the brain").

[a different tim]

There may be some part of the brain and its processing that is impossible to replicate with current knowledge, in fact probably quite a lot of it. But he is essentially arguing from irreducible comlexity, same as the ID guys (and you're right to call him on that). Basically he's offering proof by assertion ("Beethoven is too complex to be produced by a machine because I say so"). It's no defence against the lucidity of the Turing paper.

Now it is possible to make a case that computing systems, even if they replicate behaviour (i.e. actually produce the composition) miss some important aspect of consciousness - for example, Searle's Chinese room argument - but your friend doesn't seem to be bothering to actually make that case. Even Searle doesn't argue that there is something separate from the body, just something that can't be captured using a functionalist (computational) model of consciousness.

[a different tim]

There may be some part of the brain and its processing that is impossible to replicate with current knowledge, in fact probably quite a lot of it. But he is essentially arguing from irreducible comlexity, same as the ID guys (and you're right to call him on that). Basically he's offering proof by assertion ("Beethoven is too complex to be produced by a machine because I say so"). It's no defence against the lucidity of the Turing paper.

Now it is possible to make a case that computing systems, even if they replicate behaviour (i.e. actually produce the composition) miss some important aspect of consciousness - for example, Searle's Chinese room argument - but your friend doesn't seem to be bothering to actually make that case. Even Searle doesn't argue that there is something separate from the body, just something that can't be captured using a functionalist (computational) model of consciousness.

whoneedscience wrote

Now, it may well be that he is, in some sense, right, or that I'm misunderstanding him (I don't know enough about how neurons make connections or how they could be modeled in another medium, particularly silicon) but the thing that really struck me is that he's trying to make a philosophical claim that there is some human essence that is not contained in the brain: a Cartesian Soul, although he again refuses to address it. The man has a P.h.D in mathematics and studies biological systems modeling, so I'm simply baffled by this.

Does anyone have any resources or opinions on this? I'll probably see him again on Thursday. Rhinoq? Scathach? Judge?

I'm not completely sure if I am addressing what you are talking about here in regards to neuron connections or being bodeled in another medium, however a few years ago, I was watching something about scientists who have actually grown brain cells on microchips. I am trying to find some information on the study right now. I will post when I find it, or if this has absolutely nothing to do with what you are saying, I'll just stop looking...

Also, about whether or not computers can make art, that is appreciable to human standards, just take a look at fractals. I've seen some pretty amazing pictures that were done completely with computers (albeit with the input of the mathematical formulas by humans)

whoneedscience wrote

Now, it may well be that he is, in some sense, right, or that I'm misunderstanding him (I don't know enough about how neurons make connections or how they could be modeled in another medium, particularly silicon) but the thing that really struck me is that he's trying to make a philosophical claim that there is some human essence that is not contained in the brain: a Cartesian Soul, although he again refuses to address it. The man has a P.h.D in mathematics and studies biological systems modeling, so I'm simply baffled by this.

Does anyone have any resources or opinions on this? I'll probably see him again on Thursday. Rhinoq? Scathach? Judge?

I'm not completely sure if I am addressing what you are talking about here in regards to neuron connections or being bodeled in another medium, however a few years ago, I was watching something about scientists who have actually grown brain cells on microchips. I am trying to find some information on the study right now. I will post when I find it, or if this has absolutely nothing to do with what you are saying, I'll just stop looking...

Also, about whether or not computers can make art, that is appreciable to human standards, just take a look at fractals. I've seen some pretty amazing pictures that were done completely with computers (albeit with the input of the mathematical formulas by humans)

here is a link to one study done in which they grew rat hippocampal cells on silicon chips. It's in PDF format

Rat Brains

edit: that study was from 1999

edit: here's another one from 2000

more rat brains

here is a link to one study done in which they grew rat hippocampal cells on silicon chips. It's in PDF format

Rat Brains

edit: that study was from 1999

edit: here's another one from 2000

more rat brains

I'm reminded of the old LISPer joke: "Will write code that writes code for food"

I'm reminded of the old LISPer joke: "Will write code that writes code for food"