There are some ideas about how to do this. Molecular biologists are developing ways of switching small groups of neurons in an animal’s brain off and on again, so the effect on behaviour can be observed. This technique will become routine over the next decade but will probably always remain of limited value to the human brain. Directly stimulating bits of the brain with microelectrodes is another approach, but requires opening the skull.

Neuro-engineers will develop better techniques. One possibility is using focused electromagnetic fields to target a small volume of brain matter, say the size of a pin head, from outside the skull. More likely is an implantable, organo-electrical brain-machine interface. The first use of such interfaces will be for research and neuroprosthetics, but their immense promise for enhancing the human mind and for effecting some sort of human-machine blend will begin to be realised by 2056.

Brilliant Minds Forecast the Next 50 Years — find many more in our exclusive Special Report. You can also have your say on what the biggest breakthrough of the next 50 years will be, in our