Regularizing Explanations in Bayesian Convolutional Neural Networks

TL;DR

This paper introduces a novel explanation regularization technique compatible with Bayesian neural networks, enhancing their ability to focus on relevant features, improve predictive accuracy, and quantify uncertainty, especially when overfitting on spurious patterns.

Contribution

It proposes a new explanation regularization method that works with Bayesian inference, enabling better feature focus and uncertainty estimation in neural networks.

Findings

Improves predictive performance on datasets with spurious features.

Outperforms data augmentation methods in regularizing explanations.

Enhances model focus on relevant features while maintaining uncertainty quantification.

Abstract

Neural networks are powerful function approximators with tremendous potential in learning complex distributions. However, they are prone to overfitting on spurious patterns. Bayesian inference provides a principled way to regularize neural networks and give well-calibrated uncertainty estimates. It allows us to specify prior knowledge on weights. However, specifying domain knowledge via distributions over weights is infeasible. Furthermore, it is unable to correct models when they focus on spurious or irrelevant features. New methods within explainable artificial intelligence allow us to regularize explanations in the form of feature importance to add domain knowledge and correct the models' focus. Nevertheless, they are incompatible with Bayesian neural networks, as they require us to modify the loss function. We propose a new explanation regularization method that is compatible with Bayesian inference. Consequently, we can quantify uncertainty and, at the same time, have correct explanations. We test our method using four different datasets. The results show that our method improves predictive performance when models overfit on spurious features or are uncertain of which features to focus on. Moreover, our method performs better than augmenting training data with samples where spurious features are removed through masking. We provide code, data, trained weights, and hyperparameters.