Data-adaptive discriminative feature localization with statistically guaranteed interpretation

Abstract

In explainable artificial intelligence, discriminative feature localization is critical to reveal a black-box model’s decision-making process from raw data to prediction. In this article we use two real datasets, the MNIST handwritten digits and MIT-BIH electrocardiogram (ECG) signals, to motivate key characteristics of discriminative features, namely, adaptiveness, predictive importance and effectiveness. Then we develop a localization framework, based on adversarial attacks, to effectively localize discriminative features. In contrast to existing heuristic methods, we also provide a statistically guaranteed interpretability of the localized features by measuring a generalized partial ${\mathit{R}}^2$. We apply the proposed method to the MNIST dataset and the MIT-BIH dataset with a convolutional autoencoder. In the first, the compact image regions localized by the proposed method are visually appealing. Similarly, in the second, the identified ECG features are biologically plausible and consistent with cardiac electrophysiological principles while locating subtle anomalies in a QRS complex that may not be discernible by the naked eye. Overall, the proposed method compares favorably with state-of-the-art competitors. Accompanying this paper is a Python library dnn-locate that implements the proposed approach.