arXiv Machine Learning
Sep 11

Revenge of Monosemanticity: Neuron Specialization as a New Form of Feature Learning in MLPs

The paper investigates how multilayer perceptrons (MLPs) learn features in regression tasks with clustered data. It finds that instead of forming a single global low‑dimensional representation, MLPs develop monosemantic specialized neurons—each neuron aligns strongly with a specific predictive feature relevant to a particular region of the input space. This specialization results in a collection of local low‑dimensional representations, giving MLPs a provable data‑efficiency advantage over methods that rely on a global representation.

By Amirhesam Abedsoltan, Enric Boix-Adsera, Fivos Kalogiannis, Mikhail Belkin
arXiv Statistics ML
Oct 19

A Class of R\'enyi-based Concentration Metrics for Kolmogorov-Arnold Geometry in Multilayer Perceptrons

The paper introduces a new family of concentration metrics, called α-RC, based on Rényi divergence to assess how the magnitudes of Jacobian minors in multilayer perceptrons are distributed. Unlike the existing Participation Ratio, these metrics are bounded between 0 and 1 regardless of network size, with 0 meaning uniform spread and 1 indicating dominance by a single minor. For α=2, the α-RC metric reduces to a transformed version of the Participation Ratio, and experiments on single-hidden-layer MLPs demonstrate its practical advantages.

By Juan Carlos Fern\'andez, Asunci\'on Jim\'enez-Cordero, Jos\'e Francisco Paris