To determine whether simultaneously recorded motor cortex neurons can be us
ed for real-time device control, rats were trained to position a robot arm
to obtain water by pressing a lever. Mathematical transformations, includin
g neural networks, converted multineuron signals into 'neuronal population
functions' that accurately predicted lever trajectory. Next, these function
s were electronically converted into real-time signals for robot arm contro
l. After switching to this 'neurorobotic' mode, 4 of 6 animals (those with
>25 task-related neurons) routinely used these brain-derived signals to pos
ition the robot arm and obtain water. With continued training in neurorobot
ic mode, the animals' lever movement diminished or stopped. These results s
uggest a possible means for movement restoration in paralysis patients.