[anonytrary]

True, the post-processing algorithm could just be doing a randomish walk towards the answer, but I highly doubt that is what's happening. 2D cursor movement is well understood to be within the realm of possibility for EEG, so I imagine it is actually much easier with an in-vivo device. From what I understand, this is entirely supervised learning. The monkey is "telling" the device what neural pattern corresponds to moving the cursor. If I had to guess, then this chip is planted extremely close to the hippocampus, which is known to have cells that encode spatial information. The algorithm is probably doing a basic supervised learning on the cells that fire for a particular location of the cursor.

I'm just guessing on this, but the "training" session probably involved having the monkey stare at the screen for a while, while the cursor moved, which allowed the device to capture a spatial heatmap of which cells fired at which locations. There's probably some online optimization happening as the monkey then continues the "training" process by completing the task. Overall, this task is completely doable with the current technology, so I would not assume any foul play here. If the monkey was writing Shakespeare, I would definitely doubt it.

[natosaichek]

the chip is implanted in the motor cortex, I believe, so the training consisted of rewarding the monkey for moving the cursor to a target.

After the monkey has played the game a bunch, you can correlate the neuron firings generating motor signals to the arm with the motion of the cursor on the screen. Later, the monkey's arm need not actually move the joystick.

The hippocampus is pretty deep in the brain, and the Neuralink surgery can't go deeper than a centimeter or two.