The small sub-tropical island of Okinawa, some 400 miles south of Japan, is home to a unique colony of creatures. About the size of large rabbits, they possess strange translucent heads into which a single eye is embedded. They spend most of their time foraging and mating and communicate with each other using a luminescent bulb located towards the small of their backs. Their predilection for reproduction has allowed their primitive genome to evolve rapidly to adapt to their unusual circumstances. For their food is a power supply to charge their battery packs, and mating involves infrared data transfer from their hard drives. They are cyber-rodents: mobile, autonomous robots confined only to their home in the Okinawa Institute of Science and Technology by the doors of the laboratory. There are two remarkable things about the cyber-rodents. First, they demonstrate that remarkably little computational power can sustain ‘awake’, behaving organisms. Their brain is a small four-CPU onboard computer, not a giant supercomputer as you might expect. Second, many algorithms used by the rodents are based on those thought to be implemented by live rats and indeed humans. These algorithms control basic behaviours of self-preservation, mimicking the functions thought to be controlled by neuromodulators such as serotonin and dopamine. This second fact underpins a basic fact about neuroscience: if we want to understand the brain, we need to understand how it actually processes information. Like it or not, the brain is a computer, and in the same way, as we cannot hope to understand the brain of the cyber-rodent without a fair knowledge of computer science, so too we are not going to understand the human brain without some sort of neural computer science framework. It is easy to feel a bit daunted by this prospect. With 100 billion neuronal processing units …