[2602.15593] A unified theory of feature learning in RNNs and DNNs
Summary
This paper presents a unified theory of feature learning in recurrent neural networks (RNNs) and deep neural networks (DNNs), highlighting their structural similarities and distinct functional properties through a mean-field theory approach.
Why It Matters
Understanding the relationship between RNNs and DNNs is crucial for advancing machine learning techniques. This theory provides insights into how weight sharing in RNNs influences their performance on sequential tasks, potentially guiding future research and applications in AI.
Key Takeaways
- RNNs and DNNs differ primarily in weight sharing, affecting their functional properties.
- A unified mean-field theory connects architectural structure to functional biases in neural networks.
- RNNs exhibit a phase transition in performance based on the learning signal relative to noise.
- Weight sharing in RNNs aids generalization by interpolating unsupervised time steps.
- The findings may influence future designs and training methods for neural networks.
Computer Science > Machine Learning arXiv:2602.15593 (cs) [Submitted on 17 Feb 2026] Title:A unified theory of feature learning in RNNs and DNNs Authors:Jan P. Bauer, Kirsten Fischer, Moritz Helias, Agostina Palmigiano View a PDF of the paper titled A unified theory of feature learning in RNNs and DNNs, by Jan P. Bauer and 3 other authors View PDF Abstract:Recurrent and deep neural networks (RNNs/DNNs) are cornerstone architectures in machine learning. Remarkably, RNNs differ from DNNs only by weight sharing, as can be shown through unrolling in time. How does this structural similarity fit with the distinct functional properties these networks exhibit? To address this question, we here develop a unified mean-field theory for RNNs and DNNs in terms of representational kernels, describing fully trained networks in the feature learning ($\mu$P) regime. This theory casts training as Bayesian inference over sequences and patterns, directly revealing the functional implications induced by the RNNs' weight sharing. In DNN-typical tasks, we identify a phase transition when the learning signal overcomes the noise due to randomness in the weights: below this threshold, RNNs and DNNs behave identically; above it, only RNNs develop correlated representations across timesteps. For sequential tasks, the RNNs' weight sharing furthermore induces an inductive bias that aids generalization by interpolating unsupervised time steps. Overall, our theory offers a way to connect architectural s...