This illustration mixes images of a stack of sandwiches with a ResNet. The protagonist is adding a “skip connection” (blue wire) between neural layers (slices of bread). Such skip connections, inspired by biology, are the characteristic of ResNets. The skip connections allowed ResNets to be deeper than its predecessors (have a tall stack), and helped them to recognize more complex images.
Why is it good for a network to be deep? And why do skip connections help? I find it a stretch to explain them with the analogy of a sandwich, so I defer the answers to later posts. Let’s say for now that the ResNet has skip connections repeated every 2-3 layers, so it’s easy to make it deeper by stacking the same structure multiple times. That makes it look like the stacked sandwiches (see Figure 3 of the original paper).
Well, this was my first attempt at a neuroscience/AI-inspired illustration. The analogy leaves a lot to be desired, but hopefully it will get better as I try more. At least this fulfills my new year’s resolution—to post about neuroscience—on the new year’s day! 🙂