Elon Musk's Neuralink: what's science and what's not

Elon Musk wants everyone to get brain surgery. Specifically, he wants everyone to get a brain implant -- the brain-machine interface created by his company, Neuralink. He says it will be able to solve any number of medical conditions -- including paralysis, anxiety, and addiction. Machines that connect to the human brain and translate the electrical signals to a computer have been around since 2006. Since then, neuroscientists and engineers have made incremental improvements to that technology. ...