Elon Musk's startup Neuralink has shown off the latest version of its brain-machine interface, which a monkey uses to wirelessly play Pong with its mind. The demonstration is both another step forward for the ambitious company and a fascinating look at the current state of the technology, which, amongst other things, could offer sufferers of paralysis a way to regain control of their limbs.
The last time we heard from Neuralink, it had implanted one of its computer chips into the brains of pigs to demonstrate how they can record neural activity as the animals sniff around a pen. These chips consists of arrays of electrodes that record patterns of neuron activity, which can then be decoded and converted into input commands for various devices.
Previous research in this field has shown how these brain-machine interfaces can be used to control drones, prosthetic limbs and computer tablets, just by recording and relaying the user's brain activity that signals their intentions. The most impressive feats, however, have required that these brain implants be tethered to computer systems to provide the necessary bandwidth for the signals to be transmitted.
The goal for Neuralink, and many researchers in the field, is to develop a completely wireless version, which would allow sufferers of paralysis far greater freedom and quality of life. A consortium of scientists working on this problem, known as BrainGate, earlier this week revealed it had developed the first wireless system to transmit neural signals at a similar bandwidth to wired systems. It uses arrays of 200 electrodes to gather the full spectrum of signals from the brain's motor cortex and pass them along to a connected wireless transmitter on the user's head.
Aiming for far greater levels of detail, Neuralink's solution, called Link, uses arrays of 1,024 electrodes that record the neural activity. For its latest and most impressive demonstration of the technology, two of these electrode arrays were implanted into the motor cortex of a monkey named Pager and used to record neural activity as it played Pong using a joystick.
This data was relayed every 25 milliseconds over Bluetooth to decoding software, which builds a model of the relationship between certain neural patterns and the monkey's desired movements. So, some spikes might correlate with an upward movement of the joystick, and others might indicate a downward movement. In time, the decoding software can predict the direction and speed of the movements based simply on brain activity.
To demonstrate this capability, the scientists simply unplugged the joystick, which allowed the monkey to physically keep moving it in the desired direction, but with the brain activity and decoding software actually moving the paddle up and down on the screen.
While impressive, the demonstration is still just a stepping stone for Neuralink as it works to offer this same kind capability in human subjects. This would pose some challenges, as a paralyzed person would be unable to move the joystick to help build the model of brain activity as it relates to their intentions. But promisingly, other research in the field has shown how this software can be calibrated by having subjects simply imagine carrying out certain movements.
You can see Pager the monkey play Pong with its mind in the video below.
Source: Neuralink
