[ExI] Scientists Discovered ?Mini-Computers? in Human Neurons?and That?s Great News for AI

[Stuart LaForge]

Quoting John Grigg:

>
> "For 70 years, neurons were considered the basic computational unit of the
> brain. Yet according to *a new study
> <https://science.sciencemag.org/content/367/6473/83>* published this month
> in *Science*, the neurons in our cortex, the outermost ?crust? of our
> brain, seem to have uniquely evolved to sustain incredibly complex
> computations in their input cables. It?s as if someone finally obtained
> proof that your computer?s electrical wiring is actually made up of
> mini-processors, each performing calculations before sending results to a
> CPU."

Yes, the discovery that dendrites have their own calcium-mediated  
action potentials that can form biological XOR logic gates is very  
cool and amazing.

It also solves a minor mystery in physiology: the human brain is  
typically only about 2% the mass of the body, yet accounts for  
approximately 20% of its energy requirements. So while you are at  
rest, your brain burns about a fifth of the total calories you are  
burning despite having only 2% of your cells. If dendrites are XOR or  
another irreversible logic gate, then dendrites like such gates in  
general, erase information. This is because you have 2-bits going into  
the XOR gate but only 1-bit coming out. By Landauer's law,  
E>=k*T*ln(2), this must cost energy and increase the entropy of your  
environment. Since each neuron can have something like 5 dendrites and  
there are some 10^11 neurons, then that's a lot of bits being erased  
and a lot of heat and entropy being generated, and calories burned,  
just by thinking.

Stuart LaForge