Neural Networks Learn Statistics of Increasing Complexity
- URL: http://arxiv.org/abs/2402.04362v3
- Date: Wed, 09 Oct 2024 06:43:49 GMT
- Title: Neural Networks Learn Statistics of Increasing Complexity
- Authors: Nora Belrose, Quintin Pope, Lucia Quirke, Alex Mallen, Xiaoli Fern,
- Abstract summary: Distributional simplicity bias (DSB) posits that neural networks learn low-order moments of the data distribution first.
We show that networks automatically learn to perform well on maximum-entropy distributions whose low-order statistics match those of the training set early in training, then lose this ability later.
We use optimal transport methods to surgically edit the low-order statistics of one class to match those of another, and show that early-training networks treat the edited samples as if they were drawn from the target class.
- Score: 2.1004767452202637
- License:
- Abstract: The distributional simplicity bias (DSB) posits that neural networks learn low-order moments of the data distribution first, before moving on to higher-order correlations. In this work, we present compelling new evidence for the DSB by showing that networks automatically learn to perform well on maximum-entropy distributions whose low-order statistics match those of the training set early in training, then lose this ability later. We also extend the DSB to discrete domains by proving an equivalence between token $n$-gram frequencies and the moments of embedding vectors, and by finding empirical evidence for the bias in LLMs. Finally we use optimal transport methods to surgically edit the low-order statistics of one class to match those of another, and show that early-training networks treat the edited samples as if they were drawn from the target class. Code is available at https://github.com/EleutherAI/features-across-time.
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