A paralysed man in the US has fed himself mashed potatoes for the first time in eight years, aided by a computer-brain interface that reads his thoughts and sends signals to move muscles in his arm.
The world-first procedure has allowed him to control his hand by the power of thought.
The system uses decoded brain signals and sends them to sensors in his arm, reconnecting his brain with his muscles and regaining movement.
"I thought about moving my arm, and it did. I'm still wild every time I do something amazing," test-patient Bill Kochevar said.
Mr Kochevar, 53, first learned to use the system to move a virtual reality arm on a computer screen.
He told The Guardian he thinks about what he wants to do, and the system does it for him.
"Now we can tell the world it's possible to reconnect the brain and make the arm move again."
Mr Kochevar was paralysed from the neck down after crashing head first on his bike into a truck during a charity bike ride in Cleveland, Ohio.
Bolu Ajiboye, biomedical engineering assistant professor at Case Western Reserve University in Cleveland, said they were "just at the forefront of significant understanding of how to bring functions, of how to take advantage of our knowledge, and can see exponential growth".
The experimental technology, pioneered by the university, is the first in the world to restore brain-controlled reach and grasp in a person in complete paralysis.
The procedure had only been tested on one participant in the US but the team behind the research say the findings could lead to greater independence for people with paralysis.
The process involves implanting two sensors, each about the size of a baby aspirin, loaded with 96 electrodes designed to pick up nerve activity in the movement centres of the brain.
The sensors record brain signals created when Mr Kochevar imagines moving his arm, and relay them to a computer.
The computer sends the signals to the electrical stimulation system, which directs impulses through about 30 wires implanted in muscles in Mr Kochevar's arm and hand to produce specific movements.
For the movement phase of the trial, Mr Kochevar had to go through 45 weeks of rehabilitation to restore muscle tone that had atrophied over the years of inactivity.
Using the brain interface system, he can now move each joint in his right arm individually, just by thinking about it.
Mr Kochevar said the chance to do simple things for himself has been "better than I thought it would be".