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Comment by wmf

4 days ago

I think "clean" means something like each neuron encodes exactly one concept and it's possible to discover what the concept is.

But they don't. That's the whole reason they work in the first place.

Every neuron in the layer encodes fractionally something about the concepts embedded in the whole thing. It's more like a hologram than a series of connected facts.

  • Nick's claim is that that's the fundamental misinterpretation. Each neuron eventually ends up mostly doing one main thing (and the rare case that some neurons do several related things). Neurons compose to embed ideas which is a starkly different interpretation than them being holograms and fractional encodings.

    • Yes, I understand the claim. But it rests on the assumption that conflates multiple concepts that to me are substantially non-overlapping are one and the same thing. I would at least expect an explanation of why that is the case and so far I have not found it (at least not in the article).

      If neurons do 'one thing' then their position encodes the relationships then snipping out that one weight would make the net forget that one thing. And we already know from many practical experiments that this is not the case. So I really wonder what the underlying mechanism is for that claim to be true.

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Doesn't "orthogonal" convey that meaning more crisply and precisely?

  • Orthogonal means something different in mechinterp, so it'd be an overloaded term. Usually orthogonal would imply that there are actual vectors under consideration, which isn't the underlying claim.

  • Using "orthogonal" here would have the opposite effect, as it would impart a far more specific meaning which is also incorrect in this case.