Seeing red

[emjay]

In principle any comp system can be built using nothing but nand...so ultimately I'd have to say that if you knew how neurons worked, to an exacting degree...you would be able to build a replica of the system in another architecture, in nand rather than neuron.  Whether or not this theoretical machine would qualify, to you, as a precise model would be up for debate, I imagine.  All of this is only applicable if mind is comp, ofc.  

I use AND to simplify, grossly, when people are stuck on the fundamentals.....when they think that it -can't- be done.  You can zoom in and out with it.  For example, saying that if a nueron was only able to do what an and gate could do..it could yield this and this...or up higher, saying, if two centers of the brain A and B, through vastly complicated multidirectional concurrent processing involving billions of neurons yield state C...that's red apple.

Cool... that'll be a fun little project then, see if I can approximate one using nothing but logic gates And hopefully learn something about circuits in the process. But just two questions: 1. what's so special about NAND gates compared to other logic gates? and 2. Can each gate only accept two inputs or any number?

[bennyboy]

[The Grand Nudger]

[bennyboy]

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bump

[bennyboy]

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Fucking Google is watching me and fucking with my posts!

[bennyboy]

[The Grand Nudger]

No-LIFE 4life!

[emjay]

Based on what I know about neurons, I think the distribution of neurotransmitters in the brain represents at least partly a chaotic system.  Minor vibrations in the skull, the particular timing of the pulse, and almost anything else could affect the trigger timing of an indidual neuron, or possibly a group of neurons.  We often talk about QM unpredictability as adding an essentially random element to all events, but I think the brain is so complex that classical mechanics should make brain function as unpredictable as the weather, especially over long times.

I'd say dreaming is an excellent example.  Maybe you could see the strange and unpredictable content of dreams each night as a series of butterfly effects causing parts of the brain to light up and come into coordination with each other, sometimes in ways that daily sense perceptions would never allow for.

As a general rule, neurotransmitters don't stay 'outside' of neurons that long... they are released into the 'synaptic cleft' - a narrow gap between the axon of the pre-synaptic neuron and the dendrite of the post-synaptic neuron - in order to trigger receptors on the other side. But any that remains in the synaptic cleft - in the extracellular space - is either broken down or recycled by 'reuptake' in normal circumstances. If there's a problem with that process, then there'll be imbalances like you describe, but under normal circumstances it should be pretty ordered. But you're right... neurotransmitters and other substances floating around in the extracellular fluid could have wide scale effects on the whole network, adding yet another level of complexity to it's operation. Unfortunately I don't know enough about such global effectors, but I wouldn't be surprised if 'neurohormones' had exactly this effect, as a way of mobilising the whole network to act in a different way at the level of it's individual neurons. Because neurotransmitters come in different types and cause different reactions in the receiving neurons... for instance at a simple level, excitatory neurons release a different type of neurotransmitter than inhibitory neurons, causing the post-synaptic neuron to react differently at the site of the synapse, producing excitatory current in the first case and inhibitory current in the second. So in a way neurotransmitters allow the type of neuron to be identified at the synaptic level. It's pretty cool really.

As to dreams, I don't know. I think dreams are about consolidating learning... strengthening synaptic connections... but I don't know.

[The Grand Nudger]

Hey, for a darker twist.  How much is hard observation of the brain/mind worth to us?  How deep down the ethical rabbit hole would we go?  

Let me introduce you to HSD (Hallervorden-Spatz Disease).  Now called NBIA-1(neurodegeneration with brain iron accumulation type 1).   A neurological condition described in 1922, by Hallervorden and Spatz.  Brilliant neurologists.  Go read up on it if you want to be terrified.  Relentlessly progressive dementia with an equally nasty full body experience attached.

They would later lend their expertise (and hone it) in nazi germany assisting with the eugenics program and performing human experimentation.  A faustian bargain. I wonder, if we reached a terminus where no further knowledge was being produced...and we still lacked a complete explanation, would we accept defeat ethically and just smile at the mystery of it all or secretly wish for a couple of nazis to do something shitty?

[bennyboy]

Fair enough. My point is really about a kind of butterfly effect. In a sufficiently complex system, the complexities of classical mechanics will lead to unpredictability. So when we start talking about states and binary decisions, and leave out the chaos (especially as a function of time), I'm not sure whether we are still including the elements essential to the system.