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Calculus For Brain Computation

src: video, pdf

How fruit flies remember smells
How fruit flies remember smells
  • olfactory intelligence: centring -> random projection (50 to 2000) -> sparsification
  • R50R2000{0,1}2000\mathbb{R}^{50} \to \mathbb{R}^{2000} \to \{0,1\}^{2000} (sparsity at the 10% level, thresholding the top).
Random projection preserves similarity.
Random projection preserves similarity.
  • similarity is preserved by this (random-projection+threshold) procedure; similarity here defined by overlap

    • not really sure what you're gaining though? 1
  • Calculus of the Brain

    • interesting experiment: have a neuron only fire when you see Eiffel tower (vs house or Obama)
      • then super-impose Obama onto Eiffel tower, see below
      • now show Obama, and the neuron will fire (most of the time)
    • what's going on?
      • one way you can think of this is that there's the set of neurons that fire for Eiffel (memory of Eiffel), and similarly for other objects
      • when you see two things together (learning relationships, causality, hierarchy), then what happens is that these two sets of neurons are now connected/merged
      • but in order for this to make sense, the merge operation needs to be a little bit elaborate. basically you have to create the merged version (so like Eiffel+Obama), and perhaps that becomes the channel that connects the two things?
    • this basically gives you something like a calculus on the brain, basically involving set operations on neurons
Ison et al. 2016 Experiment
Ison et al. 2016 Experiment

  1. I guess, the idea is that you have a sparse representation (binary vector that can be captured by binary-firing neurons). perhaps storage, like with computers, just has to be in binary, so there's nothing particularly profound here.
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Last updated on 1/29/2022