'We’re growing brains outside of the body'

“The brains develop in the same way you would see in an embryo,” says Madeleine. This may be true, but their surroundings are rather different. In place of a womb, the disembodied brains are raised in giant incubators. Without a blood supply they are fed with a nutrient-rich fluid which is refreshed every few days. And, of course, they don’t have an immune system: everything – everything – which comes into contact with them must be disinfected first with alcohol.