Analyzing the Noise Robustness of Deep Neural Networks
This work addresses the need for fine-grained explanations of adversarial examples in deep learning, which is incremental as it builds on existing research in adversarial robustness.
The paper tackled the problem of understanding why adversarial examples mislead deep neural networks by presenting a visual analysis method that compares datapaths of adversarial and normal examples, demonstrating its promise through quantitative evaluation and a case study.
Adversarial examples, generated by adding small but intentionally imperceptible perturbations to normal examples, can mislead deep neural networks (DNNs) to make incorrect predictions. Although much work has been done on both adversarial attack and defense, a fine-grained understanding of adversarial examples is still lacking. To address this issue, we present a visual analysis method to explain why adversarial examples are misclassified. The key is to compare and analyze the datapaths of both the adversarial and normal examples. A datapath is a group of critical neurons along with their connections. We formulate the datapath extraction as a subset selection problem and solve it by constructing and training a neural network. A multi-level visualization consisting of a network-level visualization of data flows, a layer-level visualization of feature maps, and a neuron-level visualization of learned features, has been designed to help investigate how datapaths of adversarial and normal examples diverge and merge in the prediction process. A quantitative evaluation and a case study were conducted to demonstrate the promise of our method to explain the misclassification of adversarial examples.