The Neuralink paper mentions that the technology could help patients with spinal cord injuries control linked devices. However, at the presentation, Musk described implanting these devices in healthy people, making the procedures as safe and common as Lasik eye surgery. That’s a major psychological hurdle, says Wu, who today struggles to convince patients with epilepsy to have brain surgery to improve their quality of life. All surgery comes with risk of bleeding and infection, but with brain surgery in areas of the brain key for normal movement and functioning, those risks can have major implications. Even with surgery for epilepsy, for example, which doesn’t involve movement centers of the brain, there’s a risk. “What if you get a hemorrhage in the motor cortex? You could paralyze patients otherwise moving fine,” Wu says. These implants would be proposed for healthy people, and there’s never zero risk, he says.