A man paralyzed from the neck down by knife injuries sustained five years ago can now check his email, control a robot arm and even play computer games using the power of thought alone, according to John Donoghue of Brown University, who led the work reported in Nature.

Electrodes implanted in Matt Nagle’s brain measure the neural signals generated when he concentrates on trying to move one of his paralysed limbs. Software trained to recognize different patterns of neural activity then translates imagined gestures into the movement of an on-screen cursor or a robotic arm.

In the same issue of Nature, Krishna Shenoy and colleagues at Stanford University report a way to dramatically boost the efficiency of brain implants in monkeys. Using software that predicts the monkey’s intention from only the first few bursts of neural activity, the animals’ implants were able to function four times faster than normal — a rate that could enable a paralyzed person to type 15 words per minute.