The twin peaks of learning neural networks

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Demyanenko, Elizaveta, Feinauer, Christoph, Malatesta, Enrico M., Saglietti, Luca
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866914737009197056
author Demyanenko, Elizaveta
Feinauer, Christoph
Malatesta, Enrico M.
Saglietti, Luca
author_facet Demyanenko, Elizaveta
Feinauer, Christoph
Malatesta, Enrico M.
Saglietti, Luca
contents Recent works demonstrated the existence of a double-descent phenomenon for the generalization error of neural networks, where highly overparameterized models escape overfitting and achieve good test performance, at odds with the standard bias-variance trade-off described by statistical learning theory. In the present work, we explore a link between this phenomenon and the increase of complexity and sensitivity of the function represented by neural networks. In particular, we study the Boolean mean dimension (BMD), a metric developed in the context of Boolean function analysis. Focusing on a simple teacher-student setting for the random feature model, we derive a theoretical analysis based on the replica method that yields an interpretable expression for the BMD, in the high dimensional regime where the number of data points, the number of features, and the input size grow to infinity. We find that, as the degree of overparameterization of the network is increased, the BMD reaches an evident peak at the interpolation threshold, in correspondence with the generalization error peak, and then slowly approaches a low asymptotic value. The same phenomenology is then traced in numerical experiments with different model classes and training setups. Moreover, we find empirically that adversarially initialized models tend to show higher BMD values, and that models that are more robust to adversarial attacks exhibit a lower BMD.
format Preprint
id arxiv_https___arxiv_org_abs_2401_12610
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The twin peaks of learning neural networks
Demyanenko, Elizaveta
Feinauer, Christoph
Malatesta, Enrico M.
Saglietti, Luca
Machine Learning
Disordered Systems and Neural Networks
Probability
Statistics Theory
Recent works demonstrated the existence of a double-descent phenomenon for the generalization error of neural networks, where highly overparameterized models escape overfitting and achieve good test performance, at odds with the standard bias-variance trade-off described by statistical learning theory. In the present work, we explore a link between this phenomenon and the increase of complexity and sensitivity of the function represented by neural networks. In particular, we study the Boolean mean dimension (BMD), a metric developed in the context of Boolean function analysis. Focusing on a simple teacher-student setting for the random feature model, we derive a theoretical analysis based on the replica method that yields an interpretable expression for the BMD, in the high dimensional regime where the number of data points, the number of features, and the input size grow to infinity. We find that, as the degree of overparameterization of the network is increased, the BMD reaches an evident peak at the interpolation threshold, in correspondence with the generalization error peak, and then slowly approaches a low asymptotic value. The same phenomenology is then traced in numerical experiments with different model classes and training setups. Moreover, we find empirically that adversarially initialized models tend to show higher BMD values, and that models that are more robust to adversarial attacks exhibit a lower BMD.
title The twin peaks of learning neural networks
topic Machine Learning
Disordered Systems and Neural Networks
Probability
Statistics Theory
url https://arxiv.org/abs/2401.12610