"Why mathematicians are zombies."
The stream of visual processing that terminates in the parietal lobe has been called "the zombie stream" because we are unaware of much of the porcesses carried out there. "Smart" things we humans do such as speak, remember, recognise, choose, emote and create are associated with regions of the frontal and temporal cortices but our numerical abilities originate in the zombie that is the parietal cortex. Why is this? I will argue that it is because numerical processes are built on our ability to estimate magnitudes and the need to translate magnitude information about space, distance, time and other quantities into coordinates to be used for action. I will frame the argument according A Theory of Magnitude (ATOM) that makes many predictions for imaging and behavioural experiments.