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[return to "Cubic millimetre of brain mapped at nanoscale resolution"]
1. throwu+J7[view] [source] 2024-05-09 22:41:26
>>geox+(OP)
> The 3D map covers a volume of about one cubic millimetre, one-millionth of a whole brain, and contains roughly 57,000 cells and 150 million synapses — the connections between neurons.

This is great and provides a hard data point for some napkin math on how big a neural network model would have to be to emulate the human brain. 150 million synapses / 57,000 neurons is an average of 2,632 synapses per neuron. The adult human brain has 100 (+- 20) billion or 1e11 neurons so assuming the average rate of synapse/neuron holds, that's 2.6e14 total synapses.

Assuming 1 parameter per synapse, that'd make the minimum viable model several hundred times larger than state of the art GPT4 (according to the rumored 1.8e12 parameters). I don't think that's granular enough and we'd need to assume 10-100 ion channels per synapse and I think at least 10 parameters per ion channel, putting the number closer to 2.6e16+ parameters, or 4+ orders of magnitude bigger than GPT4.

There are other problems of course like implementing neuroplasticity, but it's a fun ball park calculation. Computing power should get there around 2048: >>38919548

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2. cybera+Xd[view] [source] 2024-05-09 23:41:17
>>throwu+J7
On the other hand, a significant amount of neural circuitry seems to be dedicated to "housekeeping" needs, and to functions such as locomotion.

So we might need significantly less brain matter for general intelligence.

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3. alanbe+Gt[view] [source] 2024-05-10 02:48:54
>>cybera+Xd
Or perhaps the housekeeping of existing in the physical world is a key aspect of general intelligence.
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4. Intral+0J[view] [source] 2024-05-10 06:34:51
>>alanbe+Gt
Isn't that kinda obvious? A baby that grows up in a sensory deprivation tank does not… develop, as most intelligent persons do.
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5. squigz+xv1[view] [source] 2024-05-10 13:52:03
>>Intral+0J
A true sensory deprivation tank is not a fair comparison, I think, because AI is not deprived of all its 'senses' - it is still prompted, responds, etc.

Would a baby that grows up in a sensory deprivation tank, but is still able to communicate and learn from other humans, develop in a recognizable manner?

I would think so. Let's not try it ;)

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