Visual control of our actions can be unconscious as well as conscious. For example, when a pedestrian steps onto a street and then suddenly steps back, to avoid being hit by an oncoming car, the pedestrian's visual system has been able to detect the car very rapidly. Since the registration of the approaching car in conscious vision could take a few hundreds of milliseconds - possibly too long to avoid being struck by it, the rapid injury-avoiding action has relied on the oncoming car being detected at unconscious levels in the visual system. So how, and at what level in the visual system is a...