Inspecting what a network has learned
A particularly interesting research effort is being devoted to understand what neural networks are actually learning in order to be able to recognize images so well. This is called neural network “interpretability.” Activation atlases is a promising recent technique that aims to show the feature visualizations of averaged activation functions. In this way, activation atlases produce a global map seen through the eyes of the network. Let’s look at a demo available at https://distill.pub/2019/activation-atlas/:
Figure 20.13: Examples of inspections
In this image, an InceptionV1 network used for vision classification reveals many fully realized features, such as electronics, screens, a Polaroid camera, buildings, food, animal ears, plants, and watery backgrounds. Note that grid cells are labeled with the classification they give the most support for. Grid cells are also sized according to the number of activations...