I don't think the analogy was pulled out of ... hrm, /dev/random. afaik, the brain researchers have data for opinions. E.g. the functions of the first levels o

I don't think the analogy was pulled out of ... hrm, /dev/random. afaik, the brain researchers have data for opinions. E.g. the functions of the first levels of the visual cortex is relatively well understood -- both from mapping the nerve connections and from copying the mechanism in computers. There is a long time evolutionary pressure to conserve energy, all the way back to the evolution of nerves. (The brain use quite a lot of your total energy use, unless you're a non-mechanized lumberjack...) Edit: The visual cortex might work differently than other parts of the brain (ask a researcher) because of speed demands, which otoh supports the point about energy efficiency.