Neuralink enables a monkey to play video games
Previously, the monkey was trained to play the game with a joystick. During that process, a Neuralink device was connected to the monkey's brain and collected training data. That training data was then used to understand the monkey's intent in a later trial with the joystick unplugged. In that trial all movement on the screen was controlled exclusively by brain signals interpreted by the Neuralink device.
Musk:
Later versions will be able to shunt signals from Neuralinks in brain to Neuralinks in body motor/sensory neuron clusters, thus enabling, for example, paraplegics to walk again. The device is implanted flush with skull & charges wirelessly, so you look & feel totally normal