Artificial Consciousness/Neural Correlates/Neural Models/Biochemistry Model
The Biochemistry Model of a Neuron
editI have often joked that life in general, and myself in particular, exist only to increase the partial pressure of Long Chain Molecules. While this might not be exactly true, there being other causes both before and after partial pressure, It illustrates a point that I think is important to the biochemistry of life, in general, and Neurons in particular, which is why I include it here. Life formed partially because long-chain molecules are more entropic than smaller molecules, and chemistry moves in the direction to increase entropy.
Biochemistry, (The chemistry of life) revolves around systems that developed as a result of the tendency for long-chained molecules to form. We are not sure of the exact chemical history of life, but we think that DNA formed before the cell, and that the cell formed first in vents at the ocean floor, where lipids formed into bubbles, in which other chemicals were captured. What is important about these bubbles of lipids, is that because of the mineral richness of the bubbles, they created an environment in which certain types of chemical reactions were more likely, and since those reactions resulted in long-chain molecules the result was both an increase in the partial pressure of long-chain molecules, and an increase in the entropy within the bubbles. How that resulted in the current highly complex neuron, is much too complex a story to describe here, and frankly I couldn't if I tried, if only because we don't know the story yet.
As part of my Memory Research, leading up to the writing of How Memory Might Work, I contacted a leading researcher in Memory, in the hopes I could discuss my model, before I published it. Dr. Peter Milner of McGill University in Montreal was dismissive of the concept of a Memory Model at all, and one of his comments that I considered too flip to useful at first, was that "Neurons are squishy bags of chemicals" of course he was trying to discourage me, and so the flip answer was probably meant to do just that, but there is still some wisdom to be found in his words. There is no doubt that neurons are squishy bags of chemicals, and until we can understand what those chemicals are doing, a memory model might be premature. I think that my model is timely, but accept that Dr. Milner might disagree.
If you have read the section on Synaptic Models you may have noted that the biomolecular researchers are doing wonderful things tracing out the Biomolecular traces of memory in the Neuron, Until this research is more complete we can only predict what they will find, in the hopes that our predictions will prove valuable. In any case, we can say that quite a bit more is going on in the neuron than was even hinted at by Hebbs original model, which is no great surprise. However from the work of the Neural Network Scientists we know that there is still some merit to Hebbs model even if it was a hopeless oversimplification. Neural Networks have proven capable of doing some interesting processing.
As we integrate more of the Biomolecular research into our biochemical model of the neuron we will begin to understand it even better than we do today. In the meantime it is not unreasonable to think of the neuron as being a complex environment in which many chemical processes are going on simultaneously, some of which are there because the neuron is a cell and is therefore alive, and some of which are there because the neuron is specialized to do signal propagation, memory and processing on top of its role as a separate cell in a multi-cellular being.