In a nutshell EY/LW folks got much of their brain model from the heuristics and biases, ev psych literature which is based on the evolved modularity hypothesis, which turned out to be near completely wrong. So just by merely reading the sequences and associated lit LW folks have unfortunately picked up a fairly inaccurate default view of the brain.
In a nutshell the brain is a very generic/universal learning system built mostly out of a few different complimentary types of neural computronium (cortex, cerebellum, etc) and an actual practical recursive self improvement learning system that rapidly learns efficient circuit architecture from lifetime experience. The general meta-architecture is not specific to humans, primates, or even mammals, and in fact is highly convergent and conserved—evolution found and preserved it again and again across wildly divergent lineages. So there isn’t so much room for improvement in architecture, most of the improvement comes solely from scaling.
Nonetheless there are important differences across the lineages: primates along with some birds and perhaps some octopoda have the most scaling efficient archs in terms of neuron/synapse density, but these differences are most likely due to diverging optimization pressures along a pareto efficiency frontier.
The difference in brain capabilities are then mostly just scaling differences: human brains are just 4x scaled up primate brains, having nearly zero detectable divergences from the core primate architecture (brain size is not a static feature of arch, the arch also defines a scaling plan, so you can think of size as being a tunable hyperparam with many downstream modifications to the wiring prior). Rodent brain arch has probably the worst scaling plan, probably they are optimized for speed and rarely grew large.
I already made much of the brain architecture/algorithms argument in an earlier post: “The Brain as a Universal Learning Machine”.
In a nutshell EY/LW folks got much of their brain model from the heuristics and biases, ev psych literature which is based on the evolved modularity hypothesis, which turned out to be near completely wrong. So just by merely reading the sequences and associated lit LW folks have unfortunately picked up a fairly inaccurate default view of the brain.
In a nutshell the brain is a very generic/universal learning system built mostly out of a few different complimentary types of neural computronium (cortex, cerebellum, etc) and an actual practical recursive self improvement learning system that rapidly learns efficient circuit architecture from lifetime experience. The general meta-architecture is not specific to humans, primates, or even mammals, and in fact is highly convergent and conserved—evolution found and preserved it again and again across wildly divergent lineages. So there isn’t so much room for improvement in architecture, most of the improvement comes solely from scaling.
Nonetheless there are important differences across the lineages: primates along with some birds and perhaps some octopoda have the most scaling efficient archs in terms of neuron/synapse density, but these differences are most likely due to diverging optimization pressures along a pareto efficiency frontier.
The difference in brain capabilities are then mostly just scaling differences: human brains are just 4x scaled up primate brains, having nearly zero detectable divergences from the core primate architecture (brain size is not a static feature of arch, the arch also defines a scaling plan, so you can think of size as being a tunable hyperparam with many downstream modifications to the wiring prior). Rodent brain arch has probably the worst scaling plan, probably they are optimized for speed and rarely grew large.