Human brain scanning is one of these exponentially improving technologies. As I will show in chapter 4, the temporal and spatial resolution and bandwidth of brain scanning are doubling each year. We are just now obtaining the tools sufficient to begin serious reverse engineering (decoding) of the human brain’s principles of operation. We already have impressive models and simulations of a couple dozen of the brain’s several hundred regions. Within two decades, we will have a detailed understanding of how all the regions of the human brain work.