Comment by fluoridation
2 days ago
>I haven't heard anything about biological systems doing something comparable to backpropogation
The brain isn't organized into layers like ANNs are. It's a general graph of neurons and cycles are probably common.
2 days ago
>I haven't heard anything about biological systems doing something comparable to backpropogation
The brain isn't organized into layers like ANNs are. It's a general graph of neurons and cycles are probably common.
Actually that's not true. Our neocortex - the "crumpled up" outer layer of our brain, which is basically responsible for cognition/intelligence, has a highly regular architecture. If you uncrumpled it, it'd be a thin sheet of neurons about the size of a teatowel, consisting of 6 layers of different types of neurons with a specific inter-layer and intra-layer pattern of connections. It's not a general graph at all, but rather a specific processing architecture.
None of what you've said contradicts it's a general graph instead of, say, a DAG. It doesn't rule out cyles either within a single layer or across multiple layers. And even if it did, the brain is not just the neocortex, and the neocortex isn't isolated from the rest of the topology.
It's a specific architecture. Of course there are (massive amounts) of feedback paths, since that's how we learn - top-down prediction and bottom-up sensory input. There is of course looping too - e.g. thalamo-cortical loop - we are not just as pass-thru reactionary LLM!
Yes, there is a lot more structure to the brain than just the neocortex - there are all the other major components (thalamus, hippocampus, etc) each with their own internal arhitecture, and then specific patterns of interconnect between them...
This all reinforces what I am saying - the brain is not just some random graph - it is a highly specific architecture.
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